From 3dca43fdff3a0b5442574f0728e75f4f061c216f Mon Sep 17 00:00:00 2001 From: "Philip.Hazel" Date: Tue, 18 Apr 2017 12:32:52 +0000 Subject: [PATCH] Implement PCRE2_EXTENDED_MORE and friends. --- ChangeLog | 2 + doc/html/pcre2api.html | 9 +- doc/html/pcre2compat.html | 19 +- doc/html/pcre2pattern.html | 21 +- doc/html/pcre2syntax.html | 5 +- doc/html/pcre2test.html | 9 +- doc/pcre2.txt | 2971 ++++++++++++++++++------------------ doc/pcre2api.3 | 11 +- doc/pcre2compat.3 | 16 +- doc/pcre2pattern.3 | 22 +- doc/pcre2syntax.3 | 7 +- doc/pcre2test.1 | 11 +- doc/pcre2test.txt | 708 ++++----- src/pcre2.h | 1 + src/pcre2.h.generic | 7 + src/pcre2.h.in | 1 + src/pcre2_compile.c | 69 +- src/pcre2test.c | 16 +- testdata/testinput2 | 14 + testdata/testoutput2 | 72 + testdata/testoutput8-16-2 | 4 +- testdata/testoutput8-32-2 | 2 - testdata/testoutput8-8-2 | 3 +- 23 files changed, 2084 insertions(+), 1916 deletions(-) diff --git a/ChangeLog b/ChangeLog index d63d3b3..bf50857 100644 --- a/ChangeLog +++ b/ChangeLog @@ -148,6 +148,8 @@ tests to improve coverage. (d) Avoid warning for never-use case OP_TABLE_LENGTH which is just a fudge for checking at compile time that tables are the right size. (e) Add missing "fall through" comment. + +29. Implemented PCRE2_EXTENDED_MORE and related /xx and (?xx) features. Version 10.23 14-February-2017 diff --git a/doc/html/pcre2api.html b/doc/html/pcre2api.html index a8a4638..74ef04c 100644 --- a/doc/html/pcre2api.html +++ b/doc/html/pcre2api.html @@ -1377,6 +1377,13 @@ sequence at the start of the pattern, as described in the section entitled "Newline conventions" in the pcre2pattern documentation. A default is defined when PCRE2 is built. +
+  PCRE2_EXTENDED_MORE
+
+This option has the effect of PCRE2_EXTENDED, but, in addition, space and +horizontal tab characters are also ignored inside a character class. +PCRE2_EXTENDED_MORE is equivalent to Perl's 5.26 /xx option, and it can be +changed within a pattern by a (?xx) option setting. 
   PCRE2_FIRSTLINE
@@ -3344,7 +3351,7 @@ Cambridge, England.


REVISION

-Last updated: 14 April 2017 +Last updated: 17 April 2017
Copyright © 1997-2017 University of Cambridge.
diff --git a/doc/html/pcre2compat.html b/doc/html/pcre2compat.html index df8c9d2..5c890b0 100644 --- a/doc/html/pcre2compat.html +++ b/doc/html/pcre2compat.html @@ -200,16 +200,13 @@ different way and is not Perl-compatible. (l) PCRE2 recognizes some special sequences such as (*CR) or (*NO_JIT) at the start of a pattern that set overall options that cannot be changed within the pattern. -
-
-18. The following new Perl 5.26 constructs are not yet supported in PCRE2: -
-
-(a) The Perl /a modifier restricts /d numbers to pure ascii, the new /aa -modifier restricts /i case-insensitive matching to pure ascii also, ignoring -unicode rules. This separation cannot be represented with PCRE2_UTF. -
-
+

+

+18. The Perl /a modifier restricts /d numbers to pure ascii, and the /aa +modifier restricts /i case-insensitive matching to pure ascii, ignoring Unicode +rules. This separation cannot be represented with PCRE2_UCP. +

+

19. Perl has different limits than PCRE2. See the pcre2limit documentation for details. Perl went with 5.10 from recursion to iteration @@ -232,7 +229,7 @@ Cambridge, England. REVISION

-Last updated: 17 April 2017 +Last updated: 18 April 2017
Copyright © 1997-2017 University of Cambridge.
diff --git a/doc/html/pcre2pattern.html b/doc/html/pcre2pattern.html index 66500c1..b8e9d73 100644 --- a/doc/html/pcre2pattern.html +++ b/doc/html/pcre2pattern.html @@ -1544,20 +1544,25 @@ alternative in the subpattern.


INTERNAL OPTION SETTING

-The settings of the PCRE2_CASELESS, PCRE2_MULTILINE, PCRE2_DOTALL, and -PCRE2_EXTENDED options (which are Perl-compatible) can be changed from within -the pattern by a sequence of Perl option letters enclosed between "(?" and ")". -The option letters are +The settings of the PCRE2_CASELESS, PCRE2_MULTILINE, PCRE2_DOTALL, +PCRE2_EXTENDED, and PCRE2_EXTENDED_MORE options (which are Perl-compatible) can +be changed from within the pattern by a sequence of Perl option letters +enclosed between "(?" and ")". The option letters are 

   i  for PCRE2_CASELESS
   m  for PCRE2_MULTILINE
   s  for PCRE2_DOTALL
   x  for PCRE2_EXTENDED
+  xx for PCRE2_EXTENDED_MORE
For example, (?im) sets caseless, multiline matching. It is also possible to -unset these options by preceding the letter with a hyphen, and a combined -setting and unsetting such as (?im-sx), which sets PCRE2_CASELESS and -PCRE2_MULTILINE while unsetting PCRE2_DOTALL and PCRE2_EXTENDED, is also +unset these options by preceding the letter with a hyphen. The two "extended" +options are not independent; unsetting either one cancels the effects of both +of them. +

+

+A combined setting and unsetting such as (?im-sx), which sets PCRE2_CASELESS +and PCRE2_MULTILINE while unsetting PCRE2_DOTALL and PCRE2_EXTENDED, is also permitted. If a letter appears both before and after the hyphen, the option is unset. An empty options setting "(?)" is allowed. Needless to say, it has no effect. @@ -3438,7 +3443,7 @@ Cambridge, England.


REVISION

-Last updated: 11 April 2017 +Last updated: 18 April 2017
Copyright © 1997-2017 University of Cambridge.
diff --git a/doc/html/pcre2syntax.html b/doc/html/pcre2syntax.html index 0241002..ee58070 100644 --- a/doc/html/pcre2syntax.html +++ b/doc/html/pcre2syntax.html @@ -432,7 +432,8 @@ but some of them use Unicode properties if PCRE2_UCP is set. You can use (?m) multiline (?s) single line (dotall) (?U) default ungreedy (lazy) - (?x) extended (ignore white space) + (?x) extended: ignore white space except in classes + (?xx) as (?x) but also ignore space and tab in classes (?-...) unset option(s) The following are recognized only at the very start of a pattern or after one @@ -596,7 +597,7 @@ Cambridge, England.


REVISION

-Last updated: 31 March 2017 +Last updated: 18 April 2017
Copyright © 1997-2017 University of Cambridge.
diff --git a/doc/html/pcre2test.html b/doc/html/pcre2test.html index 2e8a0b8..d24548d 100644 --- a/doc/html/pcre2test.html +++ b/doc/html/pcre2test.html @@ -560,9 +560,11 @@ Setting compilation options

The following modifiers set options for pcre2_compile(). The most common -ones have single-letter abbreviations. See +ones have single-letter abbreviations, with special handling for /x (to make +it like Perl). If a second x is present, PCRE2_EXTENDED is converted into +PCRE2_EXTENDED_MORE. A third appearance adds PCRE2_EXTENDED as well. See pcre2api -for a description of their effects. +for a description of the effects of these options. 

       allow_empty_class         set PCRE2_ALLOW_EMPTY_CLASS
       alt_bsux                  set PCRE2_ALT_BSUX
@@ -576,6 +578,7 @@ for a description of their effects.
       dupnames                  set PCRE2_DUPNAMES
       endanchored               set PCRE2_ENDANCHORED
   /x  extended                  set PCRE2_EXTENDED
+  /xx extended_more             set PCRE2_EXTENDED_MORE 
       firstline                 set PCRE2_FIRSTLINE
       match_unset_backref       set PCRE2_MATCH_UNSET_BACKREF
   /m  multiline                 set PCRE2_MULTILINE
@@ -1807,7 +1810,7 @@ Cambridge, England.
 

 
REVISION

 

-Last updated: 11 April 2017
+Last updated: 17 April 2017
 

 Copyright © 1997-2017 University of Cambridge.
 

diff --git a/doc/pcre2.txt b/doc/pcre2.txt
index 04bb9ca..4998a29 100644
--- a/doc/pcre2.txt
+++ b/doc/pcre2.txt
@@ -1396,226 +1396,233 @@ COMPILING A PATTERN
        tion entitled "Newline conventions" in the pcre2pattern  documentation.
        A default is defined when PCRE2 is built.
 
+         PCRE2_EXTENDED_MORE
+
+       This  option  has the effect of PCRE2_EXTENDED, but, in addition, space
+       and horizontal tab characters  are  also  ignored  inside  a  character
+       class.   PCRE2_EXTENDED_MORE  is  equivalent to Perl's 5.26 /xx option,
+       and it can be changed within a pattern by a (?xx) option setting.
+
          PCRE2_FIRSTLINE
 
-       If  this  option  is  set,  an  unanchored pattern is required to match
-       before or at the first  newline  in  the  subject  string,  though  the
-       matched  text  may  continue  over the newline. See also PCRE2_USE_OFF-
-       SET_LIMIT,  which  provides  a  more  general  limiting  facility.   If
-       PCRE2_FIRSTLINE  is set with an offset limit, a match must occur in the
-       first line and also within the offset limit. In other words,  whichever
+       If this option is set, an  unanchored  pattern  is  required  to  match
+       before  or  at  the  first  newline  in  the subject string, though the
+       matched text may continue over the  newline.  See  also  PCRE2_USE_OFF-
+       SET_LIMIT,   which  provides  a  more  general  limiting  facility.  If
+       PCRE2_FIRSTLINE is set with an offset limit, a match must occur in  the
+       first  line and also within the offset limit. In other words, whichever
        limit comes first is used.
 
          PCRE2_MATCH_UNSET_BACKREF
 
-       If  this  option  is set, a back reference to an unset subpattern group
-       matches an empty string (by default this causes  the  current  matching
-       alternative  to  fail).   A  pattern such as (\1)(a) succeeds when this
-       option is set (assuming it can find an "a" in the subject), whereas  it
-       fails  by  default,  for  Perl compatibility. Setting this option makes
+       If this option is set, a back reference to an  unset  subpattern  group
+       matches  an  empty  string (by default this causes the current matching
+       alternative to fail).  A pattern such as  (\1)(a)  succeeds  when  this
+       option  is set (assuming it can find an "a" in the subject), whereas it
+       fails by default, for Perl compatibility.  Setting  this  option  makes
        PCRE2 behave more like ECMAscript (aka JavaScript).
 
          PCRE2_MULTILINE
 
-       By default, for the purposes of matching "start of line"  and  "end  of
-       line",  PCRE2  treats the subject string as consisting of a single line
-       of characters, even if it actually contains  newlines.  The  "start  of
-       line"  metacharacter  (^)  matches only at the start of the string, and
-       the "end of line" metacharacter ($) matches only  at  the  end  of  the
+       By  default,  for  the purposes of matching "start of line" and "end of
+       line", PCRE2 treats the subject string as consisting of a  single  line
+       of  characters,  even  if  it actually contains newlines. The "start of
+       line" metacharacter (^) matches only at the start of  the  string,  and
+       the  "end  of  line"  metacharacter  ($) matches only at the end of the
        string,  or  before  a  terminating  newline  (except  when  PCRE2_DOL-
-       LAR_ENDONLY is set). Note, however, that unless  PCRE2_DOTALL  is  set,
+       LAR_ENDONLY  is  set).  Note, however, that unless PCRE2_DOTALL is set,
        the "any character" metacharacter (.) does not match at a newline. This
        behaviour (for ^, $, and dot) is the same as Perl.
 
-       When PCRE2_MULTILINE it is set, the "start of line" and "end  of  line"
-       constructs  match  immediately following or immediately before internal
-       newlines in the subject string, respectively, as well as  at  the  very
-       start  and  end.  This is equivalent to Perl's /m option, and it can be
+       When  PCRE2_MULTILINE  it is set, the "start of line" and "end of line"
+       constructs match immediately following or immediately  before  internal
+       newlines  in  the  subject string, respectively, as well as at the very
+       start and end. This is equivalent to Perl's /m option, and  it  can  be
        changed within a pattern by a (?m) option setting. Note that the "start
        of line" metacharacter does not match after a newline at the end of the
-       subject, for compatibility with Perl.  However, you can change this  by
-       setting  the PCRE2_ALT_CIRCUMFLEX option. If there are no newlines in a
-       subject string, or no occurrences of ^  or  $  in  a  pattern,  setting
+       subject,  for compatibility with Perl.  However, you can change this by
+       setting the PCRE2_ALT_CIRCUMFLEX option. If there are no newlines in  a
+       subject  string,  or  no  occurrences  of  ^ or $ in a pattern, setting
        PCRE2_MULTILINE has no effect.
 
          PCRE2_NEVER_BACKSLASH_C
 
-       This  option  locks out the use of \C in the pattern that is being com-
-       piled.  This escape can  cause  unpredictable  behaviour  in  UTF-8  or
-       UTF-16  modes,  because  it may leave the current matching point in the
-       middle of a multi-code-unit character. This option  may  be  useful  in
-       applications  that  process  patterns  from external sources. Note that
+       This option locks out the use of \C in the pattern that is  being  com-
+       piled.   This  escape  can  cause  unpredictable  behaviour in UTF-8 or
+       UTF-16 modes, because it may leave the current matching  point  in  the
+       middle  of  a  multi-code-unit  character. This option may be useful in
+       applications that process patterns from  external  sources.  Note  that
        there is also a build-time option that permanently locks out the use of
        \C.
 
          PCRE2_NEVER_UCP
 
-       This  option  locks  out the use of Unicode properties for handling \B,
+       This option locks out the use of Unicode properties  for  handling  \B,
        \b, \D, \d, \S, \s, \W, \w, and some of the POSIX character classes, as
-       described  for  the  PCRE2_UCP option below. In particular, it prevents
-       the creator of the pattern from enabling this facility by starting  the
-       pattern  with  (*UCP).  This  option may be useful in applications that
+       described for the PCRE2_UCP option below. In  particular,  it  prevents
+       the  creator of the pattern from enabling this facility by starting the
+       pattern with (*UCP). This option may be  useful  in  applications  that
        process patterns from external sources. The option combination PCRE_UCP
        and PCRE_NEVER_UCP causes an error.
 
          PCRE2_NEVER_UTF
 
-       This  option  locks out interpretation of the pattern as UTF-8, UTF-16,
+       This option locks out interpretation of the pattern as  UTF-8,  UTF-16,
        or UTF-32, depending on which library is in use. In particular, it pre-
-       vents  the  creator of the pattern from switching to UTF interpretation
-       by starting the pattern with (*UTF).  This  option  may  be  useful  in
-       applications  that process patterns from external sources. The combina-
+       vents the creator of the pattern from switching to  UTF  interpretation
+       by  starting  the  pattern  with  (*UTF).  This option may be useful in
+       applications that process patterns from external sources. The  combina-
        tion of PCRE2_UTF and PCRE2_NEVER_UTF causes an error.
 
          PCRE2_NO_AUTO_CAPTURE
 
        If this option is set, it disables the use of numbered capturing paren-
-       theses  in the pattern. Any opening parenthesis that is not followed by
-       ? behaves as if it were followed by ?: but named parentheses can  still
-       be  used  for  capturing  (and  they acquire numbers in the usual way).
-       There is no equivalent of this option  in  Perl.  Note  that,  if  this
-       option  is  set,  references  to  capturing  groups (back references or
-       recursion/subroutine calls) may only refer to named groups, though  the
+       theses in the pattern. Any opening parenthesis that is not followed  by
+       ?  behaves as if it were followed by ?: but named parentheses can still
+       be used for capturing (and they acquire  numbers  in  the  usual  way).
+       There  is  no  equivalent  of  this  option in Perl. Note that, if this
+       option is set, references  to  capturing  groups  (back  references  or
+       recursion/subroutine  calls) may only refer to named groups, though the
        reference can be by name or by number.
 
          PCRE2_NO_AUTO_POSSESS
 
        If this option is set, it disables "auto-possessification", which is an
-       optimization that, for example, turns a+b into a++b in order  to  avoid
-       backtracks  into  a+ that can never be successful. However, if callouts
-       are in use, auto-possessification means that some  callouts  are  never
+       optimization  that,  for example, turns a+b into a++b in order to avoid
+       backtracks into a+ that can never be successful. However,  if  callouts
+       are  in  use,  auto-possessification means that some callouts are never
        taken. You can set this option if you want the matching functions to do
-       a full unoptimized search and run all the callouts, but  it  is  mainly
+       a  full  unoptimized  search and run all the callouts, but it is mainly
        provided for testing purposes.
 
          PCRE2_NO_DOTSTAR_ANCHOR
 
        If this option is set, it disables an optimization that is applied when
-       .* is the first significant item in a top-level branch  of  a  pattern,
-       and  all  the  other branches also start with .* or with \A or \G or ^.
-       The optimization is automatically disabled for .* if it  is  inside  an
-       atomic  group or a capturing group that is the subject of a back refer-
-       ence, or if the pattern contains (*PRUNE) or (*SKIP).  When  the  opti-
-       mization  is  not disabled, such a pattern is automatically anchored if
+       .*  is  the  first significant item in a top-level branch of a pattern,
+       and all the other branches also start with .* or with \A or  \G  or  ^.
+       The  optimization  is  automatically disabled for .* if it is inside an
+       atomic group or a capturing group that is the subject of a back  refer-
+       ence,  or  if  the pattern contains (*PRUNE) or (*SKIP). When the opti-
+       mization is not disabled, such a pattern is automatically  anchored  if
        PCRE2_DOTALL is set for all the .* items and PCRE2_MULTILINE is not set
-       for  any  ^ items. Otherwise, the fact that any match must start either
-       at the start of the subject or following a newline is remembered.  Like
+       for any ^ items. Otherwise, the fact that any match must  start  either
+       at  the start of the subject or following a newline is remembered. Like
        other optimizations, this can cause callouts to be skipped.
 
          PCRE2_NO_START_OPTIMIZE
 
-       This  is  an  option whose main effect is at matching time. It does not
+       This is an option whose main effect is at matching time.  It  does  not
        change what pcre2_compile() generates, but it does affect the output of
        the JIT compiler.
 
-       There  are  a  number of optimizations that may occur at the start of a
-       match, in order to speed up the process. For example, if  it  is  known
-       that  an  unanchored  match  must  start with a specific character, the
-       matching code searches the subject for that character, and fails  imme-
-       diately  if it cannot find it, without actually running the main match-
-       ing function. This means that a special item such as (*COMMIT)  at  the
-       start  of  a  pattern is not considered until after a suitable starting
-       point for the match has been found.  Also,  when  callouts  or  (*MARK)
-       items  are  in use, these "start-up" optimizations can cause them to be
-       skipped if the pattern is never actually used. The  start-up  optimiza-
-       tions  are  in effect a pre-scan of the subject that takes place before
+       There are a number of optimizations that may occur at the  start  of  a
+       match,  in  order  to speed up the process. For example, if it is known
+       that an unanchored match must start  with  a  specific  character,  the
+       matching  code searches the subject for that character, and fails imme-
+       diately if it cannot find it, without actually running the main  match-
+       ing  function.  This means that a special item such as (*COMMIT) at the
+       start of a pattern is not considered until after  a  suitable  starting
+       point  for  the  match  has  been found. Also, when callouts or (*MARK)
+       items are in use, these "start-up" optimizations can cause them  to  be
+       skipped  if  the pattern is never actually used. The start-up optimiza-
+       tions are in effect a pre-scan of the subject that takes  place  before
        the pattern is run.
 
        The PCRE2_NO_START_OPTIMIZE option disables the start-up optimizations,
-       possibly  causing  performance  to  suffer,  but ensuring that in cases
-       where the result is "no match", the callouts do occur, and  that  items
+       possibly causing performance to suffer,  but  ensuring  that  in  cases
+       where  the  result is "no match", the callouts do occur, and that items
        such as (*COMMIT) and (*MARK) are considered at every possible starting
        position in the subject string.
 
-       Setting PCRE2_NO_START_OPTIMIZE may change the outcome  of  a  matching
+       Setting  PCRE2_NO_START_OPTIMIZE  may  change the outcome of a matching
        operation.  Consider the pattern
 
          (*COMMIT)ABC
 
-       When  this  is compiled, PCRE2 records the fact that a match must start
-       with the character "A". Suppose the subject  string  is  "DEFABC".  The
-       start-up  optimization  scans along the subject, finds "A" and runs the
-       first match attempt from there. The (*COMMIT) item means that the  pat-
-       tern  must  match the current starting position, which in this case, it
-       does. However, if the same match is  run  with  PCRE2_NO_START_OPTIMIZE
-       set,  the  initial  scan  along the subject string does not happen. The
-       first match attempt is run starting  from  "D"  and  when  this  fails,
-       (*COMMIT)  prevents  any  further  matches  being tried, so the overall
+       When this is compiled, PCRE2 records the fact that a match  must  start
+       with  the  character  "A".  Suppose the subject string is "DEFABC". The
+       start-up optimization scans along the subject, finds "A" and  runs  the
+       first  match attempt from there. The (*COMMIT) item means that the pat-
+       tern must match the current starting position, which in this  case,  it
+       does.  However,  if  the same match is run with PCRE2_NO_START_OPTIMIZE
+       set, the initial scan along the subject string  does  not  happen.  The
+       first  match  attempt  is  run  starting  from "D" and when this fails,
+       (*COMMIT) prevents any further matches  being  tried,  so  the  overall
        result is "no match". There are also other start-up optimizations.  For
        example, a minimum length for the subject may be recorded. Consider the
        pattern
 
          (*MARK:A)(X|Y)
 
-       The minimum length for a match is one  character.  If  the  subject  is
+       The  minimum  length  for  a  match is one character. If the subject is
        "ABC", there will be attempts to match "ABC", "BC", and "C". An attempt
        to match an empty string at the end of the subject does not take place,
-       because  PCRE2  knows  that  the  subject  is now too short, and so the
-       (*MARK) is never encountered. In this case, the optimization  does  not
+       because PCRE2 knows that the subject is  now  too  short,  and  so  the
+       (*MARK)  is  never encountered. In this case, the optimization does not
        affect the overall match result, which is still "no match", but it does
        affect the auxiliary information that is returned.
 
          PCRE2_NO_UTF_CHECK
 
-       When PCRE2_UTF is set, the validity of the pattern as a UTF  string  is
-       automatically  checked.  There  are  discussions  about the validity of
-       UTF-8 strings, UTF-16 strings, and UTF-32 strings in  the  pcre2unicode
-       document.  If an invalid UTF sequence is found, pcre2_compile() returns
+       When  PCRE2_UTF  is set, the validity of the pattern as a UTF string is
+       automatically checked. There are  discussions  about  the  validity  of
+       UTF-8  strings,  UTF-16 strings, and UTF-32 strings in the pcre2unicode
+       document. If an invalid UTF sequence is found, pcre2_compile()  returns
        a negative error code.
 
        If you know that your pattern is valid, and you want to skip this check
-       for  performance  reasons,  you  can set the PCRE2_NO_UTF_CHECK option.
-       When it is set, the effect of passing an invalid UTF string as  a  pat-
-       tern  is  undefined.  It  may cause your program to crash or loop. Note
-       that  this  option  can   also   be   passed   to   pcre2_match()   and
+       for performance reasons, you can  set  the  PCRE2_NO_UTF_CHECK  option.
+       When  it  is set, the effect of passing an invalid UTF string as a pat-
+       tern is undefined. It may cause your program to  crash  or  loop.  Note
+       that   this   option   can   also   be   passed  to  pcre2_match()  and
        pcre_dfa_match(), to suppress validity checking of the subject string.
 
          PCRE2_UCP
 
        This option changes the way PCRE2 processes \B, \b, \D, \d, \S, \s, \W,
-       \w, and some of the POSIX character classes.  By  default,  only  ASCII
-       characters  are recognized, but if PCRE2_UCP is set, Unicode properties
-       are used instead to classify characters. More details are given in  the
+       \w,  and  some  of  the POSIX character classes. By default, only ASCII
+       characters are recognized, but if PCRE2_UCP is set, Unicode  properties
+       are  used instead to classify characters. More details are given in the
        section on generic character types in the pcre2pattern page. If you set
-       PCRE2_UCP, matching one of the items it affects takes much longer.  The
-       option  is  available only if PCRE2 has been compiled with Unicode sup-
+       PCRE2_UCP,  matching one of the items it affects takes much longer. The
+       option is available only if PCRE2 has been compiled with  Unicode  sup-
        port (which is the default).
 
          PCRE2_UNGREEDY
 
-       This option inverts the "greediness" of the quantifiers  so  that  they
-       are  not greedy by default, but become greedy if followed by "?". It is
-       not compatible with Perl. It can also be set by a (?U)  option  setting
+       This  option  inverts  the "greediness" of the quantifiers so that they
+       are not greedy by default, but become greedy if followed by "?". It  is
+       not  compatible  with Perl. It can also be set by a (?U) option setting
        within the pattern.
 
          PCRE2_USE_OFFSET_LIMIT
 
        This option must be set for pcre2_compile() if pcre2_set_offset_limit()
-       is going to be used to set a non-default offset limit in a  match  con-
-       text  for  matches  that  use this pattern. An error is generated if an
-       offset limit is set without this option.  For  more  details,  see  the
-       description  of  pcre2_set_offset_limit() in the section that describes
+       is  going  to be used to set a non-default offset limit in a match con-
+       text for matches that use this pattern. An error  is  generated  if  an
+       offset  limit  is  set  without  this option. For more details, see the
+       description of pcre2_set_offset_limit() in the section  that  describes
        match contexts. See also the PCRE2_FIRSTLINE option above.
 
          PCRE2_UTF
 
-       This option causes PCRE2 to regard both the  pattern  and  the  subject
-       strings  that  are  subsequently processed as strings of UTF characters
-       instead of single-code-unit strings. It  is  available  when  PCRE2  is
-       built  to  include  Unicode  support (which is the default). If Unicode
-       support is not available, the use of this  option  provokes  an  error.
-       Details  of how this option changes the behaviour of PCRE2 are given in
+       This  option  causes  PCRE2  to regard both the pattern and the subject
+       strings that are subsequently processed as strings  of  UTF  characters
+       instead  of  single-code-unit  strings.  It  is available when PCRE2 is
+       built to include Unicode support (which is  the  default).  If  Unicode
+       support  is  not  available,  the use of this option provokes an error.
+       Details of how this option changes the behaviour of PCRE2 are given  in
        the pcre2unicode page.
 
 
 COMPILATION ERROR CODES
 
-       There are nearly 100 positive  error  codes  that  pcre2_compile()  may
-       return  (via  errorcode) if it finds an error in the pattern. There are
-       also some negative error codes that are used for invalid  UTF  strings.
+       There  are  nearly  100  positive  error codes that pcre2_compile() may
+       return (via errorcode) if it finds an error in the pattern.  There  are
+       also  some  negative error codes that are used for invalid UTF strings.
        These are the same as given by pcre2_match() and pcre2_dfa_match(), and
-       are described in the pcre2unicode page.  The  pcre2_get_error_message()
-       function  (see "Obtaining a textual error message" below) can be called
+       are  described  in the pcre2unicode page. The pcre2_get_error_message()
+       function (see "Obtaining a textual error message" below) can be  called
        to obtain a textual error message from any error code.
 
 
@@ -1638,53 +1645,53 @@ JUST-IN-TIME (JIT) COMPILATION
 
        void pcre2_jit_stack_free(pcre2_jit_stack *jit_stack);
 
-       These functions provide support for  JIT  compilation,  which,  if  the
-       just-in-time  compiler  is available, further processes a compiled pat-
+       These  functions  provide  support  for  JIT compilation, which, if the
+       just-in-time compiler is available, further processes a  compiled  pat-
        tern into machine code that executes much faster than the pcre2_match()
-       interpretive  matching function. Full details are given in the pcre2jit
+       interpretive matching function. Full details are given in the  pcre2jit
        documentation.
 
-       JIT compilation is a heavyweight optimization. It can  take  some  time
-       for  patterns  to  be analyzed, and for one-off matches and simple pat-
-       terns the benefit of faster execution might be offset by a much  slower
-       compilation  time.  Most (but not all) patterns can be optimized by the
+       JIT  compilation  is  a heavyweight optimization. It can take some time
+       for patterns to be analyzed, and for one-off matches  and  simple  pat-
+       terns  the benefit of faster execution might be offset by a much slower
+       compilation time.  Most (but not all) patterns can be optimized by  the
        JIT compiler.
 
 
 LOCALE SUPPORT
 
-       PCRE2 handles caseless matching, and determines whether characters  are
-       letters,  digits, or whatever, by reference to a set of tables, indexed
-       by character code point. This applies only  to  characters  whose  code
-       points  are  less than 256. By default, higher-valued code points never
-       match escapes such as \w or \d.  However, if PCRE2 is built  with  Uni-
+       PCRE2  handles caseless matching, and determines whether characters are
+       letters, digits, or whatever, by reference to a set of tables,  indexed
+       by  character  code  point.  This applies only to characters whose code
+       points are less than 256. By default, higher-valued code  points  never
+       match  escapes  such as \w or \d.  However, if PCRE2 is built with Uni-
        code support, all characters can be tested with \p and \P, or, alterna-
-       tively, the PCRE2_UCP option can be set when  a  pattern  is  compiled;
-       this  causes  \w and friends to use Unicode property support instead of
+       tively,  the  PCRE2_UCP  option  can be set when a pattern is compiled;
+       this causes \w and friends to use Unicode property support  instead  of
        the built-in tables.
 
-       The use of locales with Unicode is discouraged.  If  you  are  handling
-       characters  with  code  points  greater than 128, you should either use
+       The  use  of  locales  with Unicode is discouraged. If you are handling
+       characters with code points greater than 128,  you  should  either  use
        Unicode support, or use locales, but not try to mix the two.
 
-       PCRE2 contains an internal set of character tables  that  are  used  by
-       default.   These  are  sufficient  for many applications. Normally, the
+       PCRE2  contains  an  internal  set of character tables that are used by
+       default.  These are sufficient for  many  applications.  Normally,  the
        internal tables recognize only ASCII characters. However, when PCRE2 is
        built, it is possible to cause the internal tables to be rebuilt in the
        default "C" locale of the local system, which may cause them to be dif-
        ferent.
 
-       The  internal tables can be overridden by tables supplied by the appli-
-       cation that calls PCRE2. These may be created  in  a  different  locale
-       from  the  default.  As more and more applications change to using Uni-
+       The internal tables can be overridden by tables supplied by the  appli-
+       cation  that  calls  PCRE2.  These may be created in a different locale
+       from the default.  As more and more applications change to  using  Uni-
        code, the need for this locale support is expected to die away.
 
-       External tables are built by calling the  pcre2_maketables()  function,
-       in  the relevant locale. The result can be passed to pcre2_compile() as
-       often  as  necessary,  by  creating  a  compile  context  and   calling
-       pcre2_set_character_tables()  to  set  the  tables pointer therein. For
-       example, to build and use tables that are appropriate  for  the  French
-       locale  (where  accented  characters  with  values greater than 128 are
+       External  tables  are built by calling the pcre2_maketables() function,
+       in the relevant locale. The result can be passed to pcre2_compile()  as
+       often   as  necessary,  by  creating  a  compile  context  and  calling
+       pcre2_set_character_tables() to set the  tables  pointer  therein.  For
+       example,  to  build  and use tables that are appropriate for the French
+       locale (where accented characters with  values  greater  than  128  are
        treated as letters), the following code could be used:
 
          setlocale(LC_CTYPE, "fr_FR");
@@ -1693,15 +1700,15 @@ LOCALE SUPPORT
          pcre2_set_character_tables(ccontext, tables);
          re = pcre2_compile(..., ccontext);
 
-       The locale name "fr_FR" is used on Linux and other  Unix-like  systems;
-       if  you  are using Windows, the name for the French locale is "french".
-       It is the caller's responsibility to ensure that the memory  containing
+       The  locale  name "fr_FR" is used on Linux and other Unix-like systems;
+       if you are using Windows, the name for the French locale  is  "french".
+       It  is the caller's responsibility to ensure that the memory containing
        the tables remains available for as long as it is needed.
 
        The pointer that is passed (via the compile context) to pcre2_compile()
-       is saved with the compiled pattern, and the same  tables  are  used  by
-       pcre2_match()  and pcre_dfa_match(). Thus, for any single pattern, com-
-       pilation and matching both happen in the  same  locale,  but  different
+       is  saved  with  the  compiled pattern, and the same tables are used by
+       pcre2_match() and pcre_dfa_match(). Thus, for any single pattern,  com-
+       pilation  and  matching  both  happen in the same locale, but different
        patterns can be processed in different locales.
 
 
@@ -1709,13 +1716,13 @@ INFORMATION ABOUT A COMPILED PATTERN
 
        int pcre2_pattern_info(const pcre2 *code, uint32_t what, void *where);
 
-       The  pcre2_pattern_info()  function returns general information about a
+       The pcre2_pattern_info() function returns general information  about  a
        compiled pattern. For information about callouts, see the next section.
-       The  first  argument  for pcre2_pattern_info() is a pointer to the com-
+       The first argument for pcre2_pattern_info() is a pointer  to  the  com-
        piled pattern. The second argument specifies which piece of information
-       is  required,  and  the  third  argument  is a pointer to a variable to
-       receive the data. If the third argument is NULL, the first argument  is
-       ignored,  and  the  function  returns the size in bytes of the variable
+       is required, and the third argument is  a  pointer  to  a  variable  to
+       receive  the data. If the third argument is NULL, the first argument is
+       ignored, and the function returns the size in  bytes  of  the  variable
        that is required for the information requested. Otherwise, the yield of
        the function is zero for success, or one of the following negative num-
        bers:
@@ -1725,9 +1732,9 @@ INFORMATION ABOUT A COMPILED PATTERN
          PCRE2_ERROR_BADOPTION      the value of what was invalid
          PCRE2_ERROR_UNSET          the requested field is not set
 
-       The "magic number" is placed at the start of each compiled  pattern  as
-       an  simple check against passing an arbitrary memory pointer. Here is a
-       typical call of pcre2_pattern_info(), to obtain the length of the  com-
+       The  "magic  number" is placed at the start of each compiled pattern as
+       an simple check against passing an arbitrary memory pointer. Here is  a
+       typical  call of pcre2_pattern_info(), to obtain the length of the com-
        piled pattern:
 
          int rc;
@@ -1744,19 +1751,19 @@ INFORMATION ABOUT A COMPILED PATTERN
          PCRE2_INFO_ARGOPTIONS
 
        Return a copy of the pattern's options. The third argument should point
-       to  a  uint32_t  variable.  PCRE2_INFO_ARGOPTIONS  returns  exactly the
-       options that were passed to pcre2_compile(), whereas  PCRE2_INFO_ALLOP-
-       TIONS  returns  the compile options as modified by any top-level (*XXX)
+       to a  uint32_t  variable.  PCRE2_INFO_ARGOPTIONS  returns  exactly  the
+       options  that were passed to pcre2_compile(), whereas PCRE2_INFO_ALLOP-
+       TIONS returns the compile options as modified by any  top-level  (*XXX)
        option settings such as (*UTF) at the start of the pattern itself.
 
-       For  example,  if  the  pattern  /(*UTF)abc/  is  compiled   with   the
-       PCRE2_EXTENDED   option,   the   result  for  PCRE2_INFO_ALLOPTIONS  is
-       PCRE2_EXTENDED and PCRE2_UTF.  Option settings such as  (?i)  that  can
-       change  within  a pattern do not affect the result of PCRE2_INFO_ALLOP-
+       For   example,   if  the  pattern  /(*UTF)abc/  is  compiled  with  the
+       PCRE2_EXTENDED  option,  the  result   for   PCRE2_INFO_ALLOPTIONS   is
+       PCRE2_EXTENDED  and  PCRE2_UTF.   Option settings such as (?i) that can
+       change within a pattern do not affect the result  of  PCRE2_INFO_ALLOP-
        TIONS, even if they appear right at the start of the pattern. (This was
        different in some earlier releases.)
 
-       A  pattern compiled without PCRE2_ANCHORED is automatically anchored by
+       A pattern compiled without PCRE2_ANCHORED is automatically anchored  by
        PCRE2 if the first significant item in every top-level branch is one of
        the following:
 
@@ -1765,7 +1772,7 @@ INFORMATION ABOUT A COMPILED PATTERN
          \G    always
          .*    sometimes - see below
 
-       When  .* is the first significant item, anchoring is possible only when
+       When .* is the first significant item, anchoring is possible only  when
        all the following are true:
 
          .* is not in an atomic group
@@ -1775,172 +1782,172 @@ INFORMATION ABOUT A COMPILED PATTERN
          Neither (*PRUNE) nor (*SKIP) appears in the pattern
          PCRE2_NO_DOTSTAR_ANCHOR is not set
 
-       For patterns that are auto-anchored, the PCRE2_ANCHORED bit is  set  in
+       For  patterns  that are auto-anchored, the PCRE2_ANCHORED bit is set in
        the options returned for PCRE2_INFO_ALLOPTIONS.
 
          PCRE2_INFO_BACKREFMAX
 
-       Return  the  number  of  the highest back reference in the pattern. The
-       third argument should point to an uint32_t variable. Named  subpatterns
-       acquire  numbers  as well as names, and these count towards the highest
-       back reference.  Back references such as \4 or \g{12}  match  the  cap-
-       tured  characters of the given group, but in addition, the check that a
+       Return the number of the highest back reference  in  the  pattern.  The
+       third  argument should point to an uint32_t variable. Named subpatterns
+       acquire numbers as well as names, and these count towards  the  highest
+       back  reference.   Back  references such as \4 or \g{12} match the cap-
+       tured characters of the given group, but in addition, the check that  a
        capturing group is set in a conditional subpattern such as (?(3)a|b) is
-       also  a  back  reference.  Zero is returned if there are no back refer-
+       also a back reference. Zero is returned if there  are  no  back  refer-
        ences.
 
          PCRE2_INFO_BSR
 
        The output is a uint32_t whose value indicates what character sequences
        the \R escape sequence matches. A value of PCRE2_BSR_UNICODE means that
-       \R matches any Unicode line ending sequence; a value of  PCRE2_BSR_ANY-
+       \R  matches any Unicode line ending sequence; a value of PCRE2_BSR_ANY-
        CRLF means that \R matches only CR, LF, or CRLF.
 
          PCRE2_INFO_CAPTURECOUNT
 
-       Return  the highest capturing subpattern number in the pattern. In pat-
+       Return the highest capturing subpattern number in the pattern. In  pat-
        terns where (?| is not used, this is also the total number of capturing
        subpatterns.  The third argument should point to an uint32_t variable.
 
          PCRE2_INFO_DEPTHLIMIT
 
-       If  the  pattern set a backtracking depth limit by including an item of
-       the form (*LIMIT_DEPTH=nnnn) at the start, the value is  returned.  The
-       third  argument  should point to an unsigned 32-bit integer. If no such
-       value has been set, the call to pcre2_pattern_info() returns the  error
+       If the pattern set a backtracking depth limit by including an  item  of
+       the  form  (*LIMIT_DEPTH=nnnn) at the start, the value is returned. The
+       third argument should point to an unsigned 32-bit integer. If  no  such
+       value  has been set, the call to pcre2_pattern_info() returns the error
        PCRE2_ERROR_UNSET.
 
          PCRE2_INFO_FIRSTBITMAP
 
-       In  the absence of a single first code unit for a non-anchored pattern,
-       pcre2_compile() may construct a 256-bit table that defines a fixed  set
-       of  values for the first code unit in any match. For example, a pattern
-       that starts with [abc] results in a table with  three  bits  set.  When
-       code  unit  values greater than 255 are supported, the flag bit for 255
-       means "any code unit of value 255 or above". If such a table  was  con-
-       structed,  a pointer to it is returned. Otherwise NULL is returned. The
+       In the absence of a single first code unit for a non-anchored  pattern,
+       pcre2_compile()  may construct a 256-bit table that defines a fixed set
+       of values for the first code unit in any match. For example, a  pattern
+       that  starts  with  [abc]  results in a table with three bits set. When
+       code unit values greater than 255 are supported, the flag bit  for  255
+       means  "any  code unit of value 255 or above". If such a table was con-
+       structed, a pointer to it is returned. Otherwise NULL is returned.  The
        third argument should point to an const uint8_t * variable.
 
          PCRE2_INFO_FIRSTCODETYPE
 
        Return information about the first code unit of any matched string, for
-       a  non-anchored pattern. The third argument should point to an uint32_t
-       variable. If there is a fixed first value, for example, the letter  "c"
+       a non-anchored pattern. The third argument should point to an  uint32_t
+       variable.  If there is a fixed first value, for example, the letter "c"
        from a pattern such as (cat|cow|coyote), 1 is returned, and the charac-
-       ter value can be retrieved using PCRE2_INFO_FIRSTCODEUNIT. If there  is
-       no  fixed  first  value, but it is known that a match can occur only at
-       the start of the subject or following a newline in the  subject,  2  is
+       ter  value can be retrieved using PCRE2_INFO_FIRSTCODEUNIT. If there is
+       no fixed first value, but it is known that a match can  occur  only  at
+       the  start  of  the subject or following a newline in the subject, 2 is
        returned. Otherwise, and for anchored patterns, 0 is returned.
 
          PCRE2_INFO_FIRSTCODEUNIT
 
-       Return  the  value  of the first code unit of any matched string in the
+       Return the value of the first code unit of any matched  string  in  the
        situation where PCRE2_INFO_FIRSTCODETYPE returns 1; otherwise return 0.
-       The  third  argument should point to an uint32_t variable. In the 8-bit
-       library, the value is always less than 256. In the 16-bit  library  the
-       value  can  be  up  to 0xffff. In the 32-bit library in UTF-32 mode the
+       The third argument should point to an uint32_t variable. In  the  8-bit
+       library,  the  value is always less than 256. In the 16-bit library the
+       value can be up to 0xffff. In the 32-bit library  in  UTF-32  mode  the
        value can be up to 0x10ffff, and up to 0xffffffff when not using UTF-32
        mode.
 
          PCRE2_INFO_FRAMESIZE
 
        Return the size (in bytes) of the data frames that are used to remember
-       backtracking positions when the pattern is processed  by  pcre2_match()
-       without  the  use  of JIT. The third argument should point to an size_t
+       backtracking  positions  when the pattern is processed by pcre2_match()
+       without the use of JIT. The third argument should point  to  an  size_t
        variable. The frame size depends on the number of capturing parentheses
-       in  the  pattern.  Each  additional capturing group adds two PCRE2_SIZE
+       in the pattern. Each additional capturing  group  adds  two  PCRE2_SIZE
        variables.
 
          PCRE2_INFO_HASBACKSLASHC
 
-       Return 1 if the pattern contains any instances of \C, otherwise 0.  The
+       Return  1 if the pattern contains any instances of \C, otherwise 0. The
        third argument should point to an uint32_t variable.
 
          PCRE2_INFO_HASCRORLF
 
-       Return  1  if  the  pattern  contains any explicit matches for CR or LF
+       Return 1 if the pattern contains any explicit  matches  for  CR  or  LF
        characters, otherwise 0. The third argument should point to an uint32_t
-       variable.  An explicit match is either a literal CR or LF character, or
-       \r or  \n  or  one  of  the  equivalent  hexadecimal  or  octal  escape
+       variable. An explicit match is either a literal CR or LF character,  or
+       \r  or  \n  or  one  of  the  equivalent  hexadecimal  or  octal escape
        sequences.
 
          PCRE2_INFO_HEAPLIMIT
 
        If the pattern set a heap memory limit by including an item of the form
        (*LIMIT_HEAP=nnnn) at the start, the value is returned. The third argu-
-       ment  should  point to an unsigned 32-bit integer. If no such value has
-       been  set,  the  call  to  pcre2_pattern_info()   returns   the   error
+       ment should point to an unsigned 32-bit integer. If no such  value  has
+       been   set,   the   call  to  pcre2_pattern_info()  returns  the  error
        PCRE2_ERROR_UNSET.
 
          PCRE2_INFO_JCHANGED
 
-       Return  1  if  the (?J) or (?-J) option setting is used in the pattern,
-       otherwise 0. The third argument should point to an  uint32_t  variable.
-       (?J)  and  (?-J) set and unset the local PCRE2_DUPNAMES option, respec-
+       Return 1 if the (?J) or (?-J) option setting is used  in  the  pattern,
+       otherwise  0.  The third argument should point to an uint32_t variable.
+       (?J) and (?-J) set and unset the local PCRE2_DUPNAMES  option,  respec-
        tively.
 
          PCRE2_INFO_JITSIZE
 
-       If the compiled pattern was successfully  processed  by  pcre2_jit_com-
-       pile(),  return  the  size  of  the JIT compiled code, otherwise return
+       If  the  compiled  pattern was successfully processed by pcre2_jit_com-
+       pile(), return the size of the  JIT  compiled  code,  otherwise  return
        zero. The third argument should point to a size_t variable.
 
          PCRE2_INFO_LASTCODETYPE
 
-       Returns 1 if there is a rightmost literal code unit that must exist  in
-       any  matched string, other than at its start. The third argument should
-       point to an uint32_t  variable.  If  there  is  no  such  value,  0  is
-       returned.  When  1  is  returned,  the  code  unit  value itself can be
-       retrieved using PCRE2_INFO_LASTCODEUNIT. For anchored patterns, a  last
-       literal  value  is  recorded  only  if it follows something of variable
-       length. For example, for the pattern /^a\d+z\d+/ the returned value  is
-       1  (with  "z" returned from PCRE2_INFO_LASTCODEUNIT), but for /^a\dz\d/
+       Returns  1 if there is a rightmost literal code unit that must exist in
+       any matched string, other than at its start. The third argument  should
+       point  to  an  uint32_t  variable.  If  there  is  no  such value, 0 is
+       returned. When 1 is  returned,  the  code  unit  value  itself  can  be
+       retrieved  using PCRE2_INFO_LASTCODEUNIT. For anchored patterns, a last
+       literal value is recorded only if  it  follows  something  of  variable
+       length.  For example, for the pattern /^a\d+z\d+/ the returned value is
+       1 (with "z" returned from PCRE2_INFO_LASTCODEUNIT), but  for  /^a\dz\d/
        the returned value is 0.
 
          PCRE2_INFO_LASTCODEUNIT
 
-       Return the value of the rightmost literal data unit that must exist  in
-       any  matched  string, other than at its start, if such a value has been
-       recorded. The third argument should point to an uint32_t  variable.  If
+       Return  the value of the rightmost literal data unit that must exist in
+       any matched string, other than at its start, if such a value  has  been
+       recorded.  The  third argument should point to an uint32_t variable. If
        there is no such value, 0 is returned.
 
          PCRE2_INFO_MATCHEMPTY
 
-       Return  1  if the pattern might match an empty string, otherwise 0. The
-       third argument should point to an uint32_t  variable.  When  a  pattern
+       Return 1 if the pattern might match an empty string, otherwise  0.  The
+       third  argument  should  point  to an uint32_t variable. When a pattern
        contains recursive subroutine calls it is not always possible to deter-
-       mine whether or not it can match an empty string. PCRE2  takes  a  cau-
+       mine  whether  or  not it can match an empty string. PCRE2 takes a cau-
        tious approach and returns 1 in such cases.
 
          PCRE2_INFO_MATCHLIMIT
 
-       If  the  pattern  set  a  match  limit by including an item of the form
-       (*LIMIT_MATCH=nnnn) at the start, the  value  is  returned.  The  third
-       argument  should  point to an unsigned 32-bit integer. If no such value
-       has been set,  the  call  to  pcre2_pattern_info()  returns  the  error
+       If the pattern set a match limit by  including  an  item  of  the  form
+       (*LIMIT_MATCH=nnnn)  at  the  start,  the  value is returned. The third
+       argument should point to an unsigned 32-bit integer. If no  such  value
+       has  been  set,  the  call  to  pcre2_pattern_info()  returns the error
        PCRE2_ERROR_UNSET.
 
          PCRE2_INFO_MAXLOOKBEHIND
 
        Return the number of characters (not code units) in the longest lookbe-
-       hind assertion in the pattern. The third argument should  point  to  an
-       unsigned  32-bit  integer. This information is useful when doing multi-
-       segment matching using the partial matching facilities. Note  that  the
+       hind  assertion  in  the pattern. The third argument should point to an
+       unsigned 32-bit integer. This information is useful when  doing  multi-
+       segment  matching  using the partial matching facilities. Note that the
        simple assertions \b and \B require a one-character lookbehind. \A also
-       registers a one-character  lookbehind,  though  it  does  not  actually
-       inspect  the  previous  character.  This is to ensure that at least one
-       character from the old segment is retained when a new segment  is  pro-
+       registers  a  one-character  lookbehind,  though  it  does not actually
+       inspect the previous character. This is to ensure  that  at  least  one
+       character  from  the old segment is retained when a new segment is pro-
        cessed. Otherwise, if there are no lookbehinds in the pattern, \A might
        match incorrectly at the start of a new segment.
 
          PCRE2_INFO_MINLENGTH
 
-       If a minimum length for matching  subject  strings  was  computed,  its
-       value  is  returned.  Otherwise the returned value is 0. The value is a
-       number of characters, which in UTF mode may be different from the  num-
-       ber  of  code  units.   The  third argument should point to an uint32_t
-       variable. The value is a lower bound to  the  length  of  any  matching
-       string.  There  may  not be any strings of that length that do actually
+       If  a  minimum  length  for  matching subject strings was computed, its
+       value is returned. Otherwise the returned value is 0. The  value  is  a
+       number  of characters, which in UTF mode may be different from the num-
+       ber of code units.  The third argument  should  point  to  an  uint32_t
+       variable.  The  value  is  a  lower bound to the length of any matching
+       string. There may not be any strings of that length  that  do  actually
        match, but every string that does match is at least that long.
 
          PCRE2_INFO_NAMECOUNT
@@ -1948,50 +1955,50 @@ INFORMATION ABOUT A COMPILED PATTERN
          PCRE2_INFO_NAMETABLE
 
        PCRE2 supports the use of named as well as numbered capturing parenthe-
-       ses.  The names are just an additional way of identifying the parenthe-
+       ses. The names are just an additional way of identifying the  parenthe-
        ses, which still acquire numbers. Several convenience functions such as
-       pcre2_substring_get_byname()  are provided for extracting captured sub-
-       strings by name. It is also possible to extract the data  directly,  by
-       first  converting  the  name to a number in order to access the correct
-       pointers in the output vector (described with pcre2_match() below).  To
-       do  the  conversion,  you  need to use the name-to-number map, which is
+       pcre2_substring_get_byname() are provided for extracting captured  sub-
+       strings  by  name. It is also possible to extract the data directly, by
+       first converting the name to a number in order to  access  the  correct
+       pointers  in the output vector (described with pcre2_match() below). To
+       do the conversion, you need to use the  name-to-number  map,  which  is
        described by these three values.
 
-       The map consists of a number of  fixed-size  entries.  PCRE2_INFO_NAME-
-       COUNT  gives  the number of entries, and PCRE2_INFO_NAMEENTRYSIZE gives
-       the size of each entry in code units; both of these return  a  uint32_t
+       The  map  consists  of a number of fixed-size entries. PCRE2_INFO_NAME-
+       COUNT gives the number of entries, and  PCRE2_INFO_NAMEENTRYSIZE  gives
+       the  size  of each entry in code units; both of these return a uint32_t
        value. The entry size depends on the length of the longest name.
 
        PCRE2_INFO_NAMETABLE returns a pointer to the first entry of the table.
-       This is a PCRE2_SPTR pointer to a block of code  units.  In  the  8-bit
-       library,  the  first two bytes of each entry are the number of the cap-
+       This  is  a  PCRE2_SPTR  pointer to a block of code units. In the 8-bit
+       library, the first two bytes of each entry are the number of  the  cap-
        turing parenthesis, most significant byte first. In the 16-bit library,
-       the  pointer  points  to 16-bit code units, the first of which contains
-       the parenthesis number. In the 32-bit library, the  pointer  points  to
-       32-bit  code units, the first of which contains the parenthesis number.
+       the pointer points to 16-bit code units, the first  of  which  contains
+       the  parenthesis  number.  In the 32-bit library, the pointer points to
+       32-bit code units, the first of which contains the parenthesis  number.
        The rest of the entry is the corresponding name, zero terminated.
 
-       The names are in alphabetical order. If (?| is used to create  multiple
-       groups  with  the same number, as described in the section on duplicate
-       subpattern numbers in the pcre2pattern page, the groups  may  be  given
-       the  same  name,  but  there  is only one entry in the table. Different
+       The  names are in alphabetical order. If (?| is used to create multiple
+       groups with the same number, as described in the section  on  duplicate
+       subpattern  numbers  in  the pcre2pattern page, the groups may be given
+       the same name, but there is only one  entry  in  the  table.  Different
        names for groups of the same number are not permitted.
 
-       Duplicate names for subpatterns with different numbers  are  permitted,
-       but  only  if  PCRE2_DUPNAMES  is  set. They appear in the table in the
-       order in which they were found in the pattern. In the  absence  of  (?|
-       this  is  the  order of increasing number; when (?| is used this is not
+       Duplicate  names  for subpatterns with different numbers are permitted,
+       but only if PCRE2_DUPNAMES is set. They appear  in  the  table  in  the
+       order  in  which  they were found in the pattern. In the absence of (?|
+       this is the order of increasing number; when (?| is used  this  is  not
        necessarily the case because later subpatterns may have lower numbers.
 
-       As a simple example of the name/number table,  consider  the  following
-       pattern  after  compilation by the 8-bit library (assume PCRE2_EXTENDED
+       As  a  simple  example of the name/number table, consider the following
+       pattern after compilation by the 8-bit library  (assume  PCRE2_EXTENDED
        is set, so white space - including newlines - is ignored):
 
          (? (?(\d\d)?\d\d) -
          (?\d\d) - (?\d\d) )
 
-       There are four named subpatterns, so the table has  four  entries,  and
-       each  entry  in the table is eight bytes long. The table is as follows,
+       There  are  four  named subpatterns, so the table has four entries, and
+       each entry in the table is eight bytes long. The table is  as  follows,
        with non-printing bytes shows in hexadecimal, and undefined bytes shown
        as ??:
 
@@ -2000,8 +2007,8 @@ INFORMATION ABOUT A COMPILED PATTERN
          00 04 m  o  n  t  h  00
          00 02 y  e  a  r  00 ??
 
-       When  writing  code  to  extract  data from named subpatterns using the
-       name-to-number map, remember that the length of the entries  is  likely
+       When writing code to extract data  from  named  subpatterns  using  the
+       name-to-number  map,  remember that the length of the entries is likely
        to be different for each compiled pattern.
 
          PCRE2_INFO_NEWLINE
@@ -2019,14 +2026,14 @@ INFORMATION ABOUT A COMPILED PATTERN
 
          PCRE2_INFO_SIZE
 
-       Return the size of  the  compiled  pattern  in  bytes  (for  all  three
-       libraries).  The third argument should point to a size_t variable. This
-       value includes the size of the general data  block  that  precedes  the
-       code  units of the compiled pattern itself. The value that is used when
-       pcre2_compile() is getting memory in which to place the  compiled  pat-
-       tern  may  be  slightly  larger than the value returned by this option,
-       because there are cases where the code that calculates the size has  to
-       over-estimate.  Processing  a  pattern  with  the JIT compiler does not
+       Return  the  size  of  the  compiled  pattern  in  bytes (for all three
+       libraries). The third argument should point to a size_t variable.  This
+       value  includes  the  size  of the general data block that precedes the
+       code units of the compiled pattern itself. The value that is used  when
+       pcre2_compile()  is  getting memory in which to place the compiled pat-
+       tern may be slightly larger than the value  returned  by  this  option,
+       because  there are cases where the code that calculates the size has to
+       over-estimate. Processing a pattern with  the  JIT  compiler  does  not
        alter the value returned by this option.
 
 
@@ -2037,22 +2044,22 @@ INFORMATION ABOUT A PATTERN'S CALLOUTS
          void *user_data);
 
        A script language that supports the use of string arguments in callouts
-       might  like  to  scan  all the callouts in a pattern before running the
+       might like to scan all the callouts in a  pattern  before  running  the
        match. This can be done by calling pcre2_callout_enumerate(). The first
-       argument  is  a  pointer  to a compiled pattern, the second points to a
-       callback function, and the third is arbitrary user data.  The  callback
-       function  is  called  for  every callout in the pattern in the order in
+       argument is a pointer to a compiled pattern, the  second  points  to  a
+       callback  function,  and the third is arbitrary user data. The callback
+       function is called for every callout in the pattern  in  the  order  in
        which they appear. Its first argument is a pointer to a callout enumer-
-       ation  block,  and  its second argument is the user_data value that was
-       passed to pcre2_callout_enumerate(). The contents of the  callout  enu-
-       meration  block  are described in the pcre2callout documentation, which
+       ation block, and its second argument is the user_data  value  that  was
+       passed  to  pcre2_callout_enumerate(). The contents of the callout enu-
+       meration block are described in the pcre2callout  documentation,  which
        also gives further details about callouts.
 
 
 SERIALIZATION AND PRECOMPILING
 
-       It is possible to save compiled patterns  on  disc  or  elsewhere,  and
-       reload  them  later, subject to a number of restrictions. The functions
+       It  is  possible  to  save  compiled patterns on disc or elsewhere, and
+       reload them later, subject to a number of restrictions.  The  functions
        whose names begin with pcre2_serialize_ are used for this purpose. They
        are described in the pcre2serialize documentation.
 
@@ -2067,56 +2074,56 @@ THE MATCH DATA BLOCK
 
        void pcre2_match_data_free(pcre2_match_data *match_data);
 
-       Information  about  a  successful  or unsuccessful match is placed in a
-       match data block, which is an opaque  structure  that  is  accessed  by
-       function  calls.  In particular, the match data block contains a vector
-       of offsets into the subject string that define the matched part of  the
-       subject  and  any  substrings  that were captured. This is known as the
+       Information about a successful or unsuccessful match  is  placed  in  a
+       match  data  block,  which  is  an opaque structure that is accessed by
+       function calls. In particular, the match data block contains  a  vector
+       of  offsets into the subject string that define the matched part of the
+       subject and any substrings that were captured. This  is  known  as  the
        ovector.
 
-       Before calling pcre2_match(), pcre2_dfa_match(),  or  pcre2_jit_match()
+       Before  calling  pcre2_match(), pcre2_dfa_match(), or pcre2_jit_match()
        you must create a match data block by calling one of the creation func-
-       tions above. For pcre2_match_data_create(), the first argument  is  the
-       number  of  pairs  of  offsets  in  the ovector. One pair of offsets is
+       tions  above.  For pcre2_match_data_create(), the first argument is the
+       number of pairs of offsets in the  ovector.  One  pair  of  offsets  is
        required to identify the string that matched the whole pattern, with an
-       additional  pair for each captured substring. For example, a value of 4
-       creates enough space to record the matched portion of the subject  plus
-       three  captured  substrings. A minimum of at least 1 pair is imposed by
+       additional pair for each captured substring. For example, a value of  4
+       creates  enough space to record the matched portion of the subject plus
+       three captured substrings. A minimum of at least 1 pair is  imposed  by
        pcre2_match_data_create(), so it is always possible to return the over-
        all matched string.
 
        The second argument of pcre2_match_data_create() is a pointer to a gen-
-       eral context, which can specify custom memory management for  obtaining
+       eral  context, which can specify custom memory management for obtaining
        the memory for the match data block. If you are not using custom memory
        management, pass NULL, which causes malloc() to be used.
 
-       For pcre2_match_data_create_from_pattern(), the  first  argument  is  a
+       For  pcre2_match_data_create_from_pattern(),  the  first  argument is a
        pointer to a compiled pattern. The ovector is created to be exactly the
        right size to hold all the substrings a pattern might capture. The sec-
-       ond  argument is again a pointer to a general context, but in this case
+       ond argument is again a pointer to a general context, but in this  case
        if NULL is passed, the memory is obtained using the same allocator that
        was used for the compiled pattern (custom or default).
 
-       A  match  data block can be used many times, with the same or different
-       compiled patterns. You can extract information from a match data  block
+       A match data block can be used many times, with the same  or  different
+       compiled  patterns. You can extract information from a match data block
        after  a  match  operation  has  finished,  using  functions  that  are
-       described in the sections on  matched  strings  and  other  match  data
+       described  in  the  sections  on  matched  strings and other match data
        below.
 
-       When  a  call  of  pcre2_match()  fails, valid data is available in the
-       match   block   only   when   the   error    is    PCRE2_ERROR_NOMATCH,
-       PCRE2_ERROR_PARTIAL,  or  one  of  the  error  codes for an invalid UTF
+       When a call of pcre2_match() fails, valid  data  is  available  in  the
+       match    block    only   when   the   error   is   PCRE2_ERROR_NOMATCH,
+       PCRE2_ERROR_PARTIAL, or one of the  error  codes  for  an  invalid  UTF
        string. Exactly what is available depends on the error, and is detailed
        below.
 
-       When  one of the matching functions is called, pointers to the compiled
-       pattern and the subject string are set in the match data block so  that
-       they  can  be  referenced  by the extraction functions. After running a
-       match, you must not free a compiled pattern or a subject  string  until
-       after  all  operations  on  the  match data block (for that match) have
+       When one of the matching functions is called, pointers to the  compiled
+       pattern  and the subject string are set in the match data block so that
+       they can be referenced by the extraction  functions.  After  running  a
+       match,  you  must not free a compiled pattern or a subject string until
+       after all operations on the match data  block  (for  that  match)  have
        taken place.
 
-       When a match data block itself is no longer needed, it should be  freed
+       When  a match data block itself is no longer needed, it should be freed
        by calling pcre2_match_data_free().
 
 
@@ -2127,15 +2134,15 @@ MATCHING A PATTERN: THE TRADITIONAL FUNCTION
          uint32_t options, pcre2_match_data *match_data,
          pcre2_match_context *mcontext);
 
-       The  function pcre2_match() is called to match a subject string against
-       a compiled pattern, which is passed in the code argument. You can  call
+       The function pcre2_match() is called to match a subject string  against
+       a  compiled pattern, which is passed in the code argument. You can call
        pcre2_match() with the same code argument as many times as you like, in
-       order to find multiple matches in the subject string or to  match  dif-
+       order  to  find multiple matches in the subject string or to match dif-
        ferent subject strings with the same pattern.
 
-       This  function  is  the  main  matching facility of the library, and it
-       operates in a Perl-like manner. For specialist use  there  is  also  an
-       alternative  matching function, which is described below in the section
+       This function is the main matching facility  of  the  library,  and  it
+       operates  in  a  Perl-like  manner. For specialist use there is also an
+       alternative matching function, which is described below in the  section
        about the pcre2_dfa_match() function.
 
        Here is an example of a simple call to pcre2_match():
@@ -2150,187 +2157,187 @@ MATCHING A PATTERN: THE TRADITIONAL FUNCTION
            match_data,     /* the match data block */
            NULL);          /* a match context; NULL means use defaults */
 
-       If the subject string is zero-terminated, the length can  be  given  as
+       If  the  subject  string is zero-terminated, the length can be given as
        PCRE2_ZERO_TERMINATED. A match context must be provided if certain less
        common matching parameters are to be changed. For details, see the sec-
        tion on the match context above.
 
    The string to be matched by pcre2_match()
 
-       The  subject string is passed to pcre2_match() as a pointer in subject,
-       a length in length, and a starting offset in  startoffset.  The  length
-       and  offset  are  in  code units, not characters.  That is, they are in
-       bytes for the 8-bit library, 16-bit code units for the 16-bit  library,
-       and  32-bit  code units for the 32-bit library, whether or not UTF pro-
+       The subject string is passed to pcre2_match() as a pointer in  subject,
+       a  length  in  length, and a starting offset in startoffset. The length
+       and offset are in code units, not characters.  That  is,  they  are  in
+       bytes  for the 8-bit library, 16-bit code units for the 16-bit library,
+       and 32-bit code units for the 32-bit library, whether or not  UTF  pro-
        cessing is enabled.
 
        If startoffset is greater than the length of the subject, pcre2_match()
-       returns  PCRE2_ERROR_BADOFFSET.  When  the starting offset is zero, the
-       search for a match starts at the beginning of the subject, and this  is
+       returns PCRE2_ERROR_BADOFFSET. When the starting offset  is  zero,  the
+       search  for a match starts at the beginning of the subject, and this is
        by far the most common case. In UTF-8 or UTF-16 mode, the starting off-
-       set must point to the start of a character, or to the end of  the  sub-
-       ject  (in  UTF-32 mode, one code unit equals one character, so all off-
-       sets are valid). Like the  pattern  string,  the  subject  may  contain
+       set  must  point to the start of a character, or to the end of the sub-
+       ject (in UTF-32 mode, one code unit equals one character, so  all  off-
+       sets  are  valid).  Like  the  pattern  string, the subject may contain
        binary zeroes.
 
-       A  non-zero  starting offset is useful when searching for another match
-       in the same subject by calling pcre2_match()  again  after  a  previous
-       success.   Setting  startoffset  differs  from passing over a shortened
-       string and setting PCRE2_NOTBOL in the case of a  pattern  that  begins
+       A non-zero starting offset is useful when searching for  another  match
+       in  the  same  subject  by calling pcre2_match() again after a previous
+       success.  Setting startoffset differs from  passing  over  a  shortened
+       string  and  setting  PCRE2_NOTBOL in the case of a pattern that begins
        with any kind of lookbehind. For example, consider the pattern
 
          \Biss\B
 
-       which  finds  occurrences  of "iss" in the middle of words. (\B matches
-       only if the current position in the subject is not  a  word  boundary.)
+       which finds occurrences of "iss" in the middle of  words.  (\B  matches
+       only  if  the  current position in the subject is not a word boundary.)
        When applied to the string "Mississipi" the first call to pcre2_match()
-       finds the first occurrence. If pcre2_match() is called again with  just
-       the  remainder  of  the  subject,  namely  "issipi", it does not match,
+       finds  the first occurrence. If pcre2_match() is called again with just
+       the remainder of the subject,  namely  "issipi",  it  does  not  match,
        because \B is always false at the start of the subject, which is deemed
-       to  be  a word boundary. However, if pcre2_match() is passed the entire
+       to be a word boundary. However, if pcre2_match() is passed  the  entire
        string again, but with startoffset set to 4, it finds the second occur-
-       rence  of "iss" because it is able to look behind the starting point to
+       rence of "iss" because it is able to look behind the starting point  to
        discover that it is preceded by a letter.
 
-       Finding all the matches in a subject is tricky  when  the  pattern  can
+       Finding  all  the  matches  in a subject is tricky when the pattern can
        match an empty string. It is possible to emulate Perl's /g behaviour by
-       first  trying  the  match  again  at  the   same   offset,   with   the
-       PCRE2_NOTEMPTY_ATSTART  and  PCRE2_ANCHORED  options,  and then if that
-       fails, advancing the starting  offset  and  trying  an  ordinary  match
-       again.  There  is  some  code  that  demonstrates how to do this in the
-       pcre2demo sample program. In the most general case, you have  to  check
-       to  see  if the newline convention recognizes CRLF as a newline, and if
-       so, and the current character is CR followed by LF, advance the  start-
+       first   trying   the   match   again  at  the  same  offset,  with  the
+       PCRE2_NOTEMPTY_ATSTART and PCRE2_ANCHORED options,  and  then  if  that
+       fails,  advancing  the  starting  offset  and  trying an ordinary match
+       again. There is some code that demonstrates  how  to  do  this  in  the
+       pcre2demo  sample  program. In the most general case, you have to check
+       to see if the newline convention recognizes CRLF as a newline,  and  if
+       so,  and the current character is CR followed by LF, advance the start-
        ing offset by two characters instead of one.
 
-       If  a  non-zero starting offset is passed when the pattern is anchored,
-       an single attempt to match at the given offset is made. This  can  only
+       If a non-zero starting offset is passed when the pattern  is  anchored,
+       an  single  attempt to match at the given offset is made. This can only
        succeed if the pattern does not require the match to be at the start of
-       the subject. In other words, the anchoring must be the result  of  set-
-       ting  the PCRE2_ANCHORED option or the use of .* with PCRE2_DOTALL, not
+       the  subject.  In other words, the anchoring must be the result of set-
+       ting the PCRE2_ANCHORED option or the use of .* with PCRE2_DOTALL,  not
        by starting the pattern with ^ or \A.
 
    Option bits for pcre2_match()
 
        The unused bits of the options argument for pcre2_match() must be zero.
-       The  only  bits  that may be set are PCRE2_ANCHORED, PCRE2_ENDANCHORED,
-       PCRE2_NOTBOL,  PCRE2_NOTEOL,  PCRE2_NOTEMPTY,   PCRE2_NOTEMPTY_ATSTART,
-       PCRE2_NO_JIT,  PCRE2_NO_UTF_CHECK,  PCRE2_PARTIAL_HARD,  and PCRE2_PAR-
+       The only bits that may be set  are  PCRE2_ANCHORED,  PCRE2_ENDANCHORED,
+       PCRE2_NOTBOL,   PCRE2_NOTEOL,  PCRE2_NOTEMPTY,  PCRE2_NOTEMPTY_ATSTART,
+       PCRE2_NO_JIT, PCRE2_NO_UTF_CHECK,  PCRE2_PARTIAL_HARD,  and  PCRE2_PAR-
        TIAL_SOFT.  Their action is described below.
 
-       Setting PCRE2_ANCHORED or PCRE2_ENDANCHORED at match time is  not  sup-
-       ported  by  the just-in-time (JIT) compiler. If it is set, JIT matching
-       is disabled and the interpretive code in pcre2_match()  is  run.  Apart
-       from  PCRE2_NO_JIT (obviously), the remaining options are supported for
+       Setting  PCRE2_ANCHORED  or PCRE2_ENDANCHORED at match time is not sup-
+       ported by the just-in-time (JIT) compiler. If it is set,  JIT  matching
+       is  disabled  and  the interpretive code in pcre2_match() is run. Apart
+       from PCRE2_NO_JIT (obviously), the remaining options are supported  for
        JIT matching.
 
          PCRE2_ANCHORED
 
        The PCRE2_ANCHORED option limits pcre2_match() to matching at the first
-       matching  position.  If  a pattern was compiled with PCRE2_ANCHORED, or
-       turned out to be anchored by virtue of its contents, it cannot be  made
-       unachored  at matching time. Note that setting the option at match time
+       matching position. If a pattern was compiled  with  PCRE2_ANCHORED,  or
+       turned  out to be anchored by virtue of its contents, it cannot be made
+       unachored at matching time. Note that setting the option at match  time
        disables JIT matching.
 
          PCRE2_ENDANCHORED
 
-       If the PCRE2_ENDANCHORED option is set, any string  that  pcre2_match()
-       matches  must be right at the end of the subject string. Note that set-
+       If  the  PCRE2_ENDANCHORED option is set, any string that pcre2_match()
+       matches must be right at the end of the subject string. Note that  set-
        ting the option at match time disables JIT matching.
 
          PCRE2_NOTBOL
 
        This option specifies that first character of the subject string is not
-       the  beginning  of  a  line, so the circumflex metacharacter should not
-       match before it. Setting this without  having  set  PCRE2_MULTILINE  at
+       the beginning of a line, so the  circumflex  metacharacter  should  not
+       match  before  it.  Setting  this without having set PCRE2_MULTILINE at
        compile time causes circumflex never to match. This option affects only
        the behaviour of the circumflex metacharacter. It does not affect \A.
 
          PCRE2_NOTEOL
 
        This option specifies that the end of the subject string is not the end
-       of  a line, so the dollar metacharacter should not match it nor (except
-       in multiline mode) a newline immediately before it. Setting this  with-
-       out  having  set PCRE2_MULTILINE at compile time causes dollar never to
+       of a line, so the dollar metacharacter should not match it nor  (except
+       in  multiline mode) a newline immediately before it. Setting this with-
+       out having set PCRE2_MULTILINE at compile time causes dollar  never  to
        match. This option affects only the behaviour of the dollar metacharac-
        ter. It does not affect \Z or \z.
 
          PCRE2_NOTEMPTY
 
        An empty string is not considered to be a valid match if this option is
-       set. If there are alternatives in the pattern, they are tried.  If  all
-       the  alternatives  match  the empty string, the entire match fails. For
+       set.  If  there are alternatives in the pattern, they are tried. If all
+       the alternatives match the empty string, the entire  match  fails.  For
        example, if the pattern
 
          a?b?
 
-       is applied to a string not beginning with "a" or  "b",  it  matches  an
+       is  applied  to  a  string not beginning with "a" or "b", it matches an
        empty string at the start of the subject. With PCRE2_NOTEMPTY set, this
-       match is not valid, so pcre2_match() searches further into  the  string
+       match  is  not valid, so pcre2_match() searches further into the string
        for occurrences of "a" or "b".
 
          PCRE2_NOTEMPTY_ATSTART
 
-       This  is  like PCRE2_NOTEMPTY, except that it locks out an empty string
+       This is like PCRE2_NOTEMPTY, except that it locks out an  empty  string
        match only at the first matching position, that is, at the start of the
-       subject  plus  the  starting offset. An empty string match later in the
-       subject is permitted.  If the pattern is anchored,  such  a  match  can
+       subject plus the starting offset. An empty string match  later  in  the
+       subject  is  permitted.   If  the pattern is anchored, such a match can
        occur only if the pattern contains \K.
 
          PCRE2_NO_JIT
 
-       By   default,   if   a  pattern  has  been  successfully  processed  by
-       pcre2_jit_compile(), JIT is automatically used  when  pcre2_match()  is
-       called  with  options  that JIT supports. Setting PCRE2_NO_JIT disables
+       By  default,  if  a  pattern  has  been   successfully   processed   by
+       pcre2_jit_compile(),  JIT  is  automatically used when pcre2_match() is
+       called with options that JIT supports.  Setting  PCRE2_NO_JIT  disables
        the use of JIT; it forces matching to be done by the interpreter.
 
          PCRE2_NO_UTF_CHECK
 
        When PCRE2_UTF is set at compile time, the validity of the subject as a
-       UTF  string  is  checked  by default when pcre2_match() is subsequently
-       called.  If a non-zero starting offset is given, the check  is  applied
-       only  to that part of the subject that could be inspected during match-
-       ing, and there is a check that the starting offset points to the  first
-       code  unit of a character or to the end of the subject. If there are no
-       lookbehind assertions in the pattern, the check starts at the  starting
-       offset.  Otherwise,  it  starts at the length of the longest lookbehind
+       UTF string is checked by default  when  pcre2_match()  is  subsequently
+       called.   If  a non-zero starting offset is given, the check is applied
+       only to that part of the subject that could be inspected during  match-
+       ing,  and there is a check that the starting offset points to the first
+       code unit of a character or to the end of the subject. If there are  no
+       lookbehind  assertions in the pattern, the check starts at the starting
+       offset. Otherwise, it starts at the length of  the  longest  lookbehind
        before the starting offset, or at the start of the subject if there are
-       not  that  many  characters  before  the starting offset. Note that the
+       not that many characters before the  starting  offset.  Note  that  the
        sequences \b and \B are one-character lookbehinds.
 
        The check is carried out before any other processing takes place, and a
-       negative  error  code is returned if the check fails. There are several
-       UTF error codes for each code unit width,  corresponding  to  different
-       problems  with  the code unit sequence. There are discussions about the
-       validity of UTF-8 strings, UTF-16 strings, and UTF-32  strings  in  the
+       negative error code is returned if the check fails. There  are  several
+       UTF  error  codes  for each code unit width, corresponding to different
+       problems with the code unit sequence. There are discussions  about  the
+       validity  of  UTF-8  strings, UTF-16 strings, and UTF-32 strings in the
        pcre2unicode page.
 
-       If  you  know  that  your  subject is valid, and you want to skip these
-       checks for performance reasons,  you  can  set  the  PCRE2_NO_UTF_CHECK
-       option  when  calling  pcre2_match(). You might want to do this for the
+       If you know that your subject is valid, and  you  want  to  skip  these
+       checks  for  performance  reasons,  you  can set the PCRE2_NO_UTF_CHECK
+       option when calling pcre2_match(). You might want to do  this  for  the
        second and subsequent calls to pcre2_match() if you are making repeated
        calls to find other matches in the same subject string.
 
-       WARNING:  When  PCRE2_NO_UTF_CHECK  is  set,  the  effect of passing an
-       invalid string as a subject, or an invalid  value  of  startoffset,  is
+       WARNING: When PCRE2_NO_UTF_CHECK is  set,  the  effect  of  passing  an
+       invalid  string  as  a  subject, or an invalid value of startoffset, is
        undefined.  Your program may crash or loop indefinitely.
 
          PCRE2_PARTIAL_HARD
          PCRE2_PARTIAL_SOFT
 
-       These  options  turn  on  the partial matching feature. A partial match
-       occurs if the end of the subject string is  reached  successfully,  but
-       there  are not enough subject characters to complete the match. If this
-       happens when PCRE2_PARTIAL_SOFT (but not  PCRE2_PARTIAL_HARD)  is  set,
-       matching  continues  by  testing any remaining alternatives. Only if no
-       complete match can be found is PCRE2_ERROR_PARTIAL returned instead  of
-       PCRE2_ERROR_NOMATCH.  In other words, PCRE2_PARTIAL_SOFT specifies that
-       the caller is prepared to handle a partial match, but only if  no  com-
+       These options turn on the partial matching  feature.  A  partial  match
+       occurs  if  the  end of the subject string is reached successfully, but
+       there are not enough subject characters to complete the match. If  this
+       happens  when  PCRE2_PARTIAL_SOFT  (but not PCRE2_PARTIAL_HARD) is set,
+       matching continues by testing any remaining alternatives.  Only  if  no
+       complete  match can be found is PCRE2_ERROR_PARTIAL returned instead of
+       PCRE2_ERROR_NOMATCH. In other words, PCRE2_PARTIAL_SOFT specifies  that
+       the  caller  is prepared to handle a partial match, but only if no com-
        plete match can be found.
 
-       If  PCRE2_PARTIAL_HARD is set, it overrides PCRE2_PARTIAL_SOFT. In this
-       case, if a partial match is found,  pcre2_match()  immediately  returns
-       PCRE2_ERROR_PARTIAL,  without  considering  any  other alternatives. In
+       If PCRE2_PARTIAL_HARD is set, it overrides PCRE2_PARTIAL_SOFT. In  this
+       case,  if  a  partial match is found, pcre2_match() immediately returns
+       PCRE2_ERROR_PARTIAL, without considering  any  other  alternatives.  In
        other words, when PCRE2_PARTIAL_HARD is set, a partial match is consid-
        ered to be more important that an alternative complete match.
 
@@ -2340,38 +2347,38 @@ MATCHING A PATTERN: THE TRADITIONAL FUNCTION
 
 NEWLINE HANDLING WHEN MATCHING
 
-       When PCRE2 is built, a default newline convention is set; this is  usu-
-       ally  the standard convention for the operating system. The default can
-       be overridden in a compile context by calling  pcre2_set_newline().  It
-       can  also be overridden by starting a pattern string with, for example,
-       (*CRLF), as described in the section  on  newline  conventions  in  the
-       pcre2pattern  page. During matching, the newline choice affects the be-
-       haviour of the dot, circumflex, and dollar metacharacters. It may  also
-       alter  the  way  the  match starting position is advanced after a match
+       When  PCRE2 is built, a default newline convention is set; this is usu-
+       ally the standard convention for the operating system. The default  can
+       be  overridden  in a compile context by calling pcre2_set_newline(). It
+       can also be overridden by starting a pattern string with, for  example,
+       (*CRLF),  as  described  in  the  section on newline conventions in the
+       pcre2pattern page. During matching, the newline choice affects the  be-
+       haviour  of the dot, circumflex, and dollar metacharacters. It may also
+       alter the way the match starting position is  advanced  after  a  match
        failure for an unanchored pattern.
 
        When PCRE2_NEWLINE_CRLF, PCRE2_NEWLINE_ANYCRLF, or PCRE2_NEWLINE_ANY is
-       set  as  the  newline convention, and a match attempt for an unanchored
+       set as the newline convention, and a match attempt  for  an  unanchored
        pattern fails when the current starting position is at a CRLF sequence,
-       and  the  pattern contains no explicit matches for CR or LF characters,
-       the match position is advanced by two characters  instead  of  one,  in
+       and the pattern contains no explicit matches for CR or  LF  characters,
+       the  match  position  is  advanced by two characters instead of one, in
        other words, to after the CRLF.
 
        The above rule is a compromise that makes the most common cases work as
-       expected. For example, if the pattern  is  .+A  (and  the  PCRE2_DOTALL
+       expected.  For  example,  if  the  pattern is .+A (and the PCRE2_DOTALL
        option is not set), it does not match the string "\r\nA" because, after
-       failing at the start, it skips both the CR and the LF before  retrying.
-       However,  the  pattern  [\r\n]A does match that string, because it con-
+       failing  at the start, it skips both the CR and the LF before retrying.
+       However, the pattern [\r\n]A does match that string,  because  it  con-
        tains an explicit CR or LF reference, and so advances only by one char-
        acter after the first failure.
 
        An explicit match for CR of LF is either a literal appearance of one of
-       those characters in the pattern, or one of the \r or \n  or  equivalent
+       those  characters  in the pattern, or one of the \r or \n or equivalent
        octal or hexadecimal escape sequences. Implicit matches such as [^X] do
-       not count, nor does \s, even though it includes CR and LF in the  char-
+       not  count, nor does \s, even though it includes CR and LF in the char-
        acters that it matches.
 
-       Notwithstanding  the above, anomalous effects may still occur when CRLF
+       Notwithstanding the above, anomalous effects may still occur when  CRLF
        is a valid newline sequence and explicit \r or \n escapes appear in the
        pattern.
 
@@ -2382,81 +2389,81 @@ HOW PCRE2_MATCH() RETURNS A STRING AND CAPTURED SUBSTRINGS
 
        PCRE2_SIZE *pcre2_get_ovector_pointer(pcre2_match_data *match_data);
 
-       In  general, a pattern matches a certain portion of the subject, and in
-       addition, further substrings from the subject  may  be  picked  out  by
-       parenthesized  parts  of  the  pattern.  Following the usage in Jeffrey
-       Friedl's book, this is called "capturing"  in  what  follows,  and  the
-       phrase  "capturing subpattern" or "capturing group" is used for a frag-
-       ment of a pattern that picks out a substring.  PCRE2  supports  several
+       In general, a pattern matches a certain portion of the subject, and  in
+       addition,  further  substrings  from  the  subject may be picked out by
+       parenthesized parts of the pattern.  Following  the  usage  in  Jeffrey
+       Friedl's  book,  this  is  called  "capturing" in what follows, and the
+       phrase "capturing subpattern" or "capturing group" is used for a  frag-
+       ment  of  a  pattern that picks out a substring. PCRE2 supports several
        other kinds of parenthesized subpattern that do not cause substrings to
-       be captured. The pcre2_pattern_info() function can be used to find  out
+       be  captured. The pcre2_pattern_info() function can be used to find out
        how many capturing subpatterns there are in a compiled pattern.
 
-       You  can  use  auxiliary functions for accessing captured substrings by
+       You can use auxiliary functions for accessing  captured  substrings  by
        number or by name, as described in sections below.
 
        Alternatively, you can make direct use of the vector of PCRE2_SIZE val-
-       ues,  called  the  ovector,  which  contains  the  offsets  of captured
-       strings.  It  is  part  of  the  match  data   block.    The   function
-       pcre2_get_ovector_pointer()  returns  the  address  of the ovector, and
+       ues, called  the  ovector,  which  contains  the  offsets  of  captured
+       strings.   It   is   part  of  the  match  data  block.   The  function
+       pcre2_get_ovector_pointer() returns the address  of  the  ovector,  and
        pcre2_get_ovector_count() returns the number of pairs of values it con-
        tains.
 
        Within the ovector, the first in each pair of values is set to the off-
        set of the first code unit of a substring, and the second is set to the
-       offset  of the first code unit after the end of a substring. These val-
-       ues are always code unit offsets, not character offsets. That is,  they
-       are  byte  offsets  in  the 8-bit library, 16-bit offsets in the 16-bit
+       offset of the first code unit after the end of a substring. These  val-
+       ues  are always code unit offsets, not character offsets. That is, they
+       are byte offsets in the 8-bit library, 16-bit  offsets  in  the  16-bit
        library, and 32-bit offsets in the 32-bit library.
 
-       After a partial match  (error  return  PCRE2_ERROR_PARTIAL),  only  the
-       first  pair  of  offsets  (that is, ovector[0] and ovector[1]) are set.
-       They identify the part of the subject that was partially  matched.  See
+       After  a  partial  match  (error  return PCRE2_ERROR_PARTIAL), only the
+       first pair of offsets (that is, ovector[0]  and  ovector[1])  are  set.
+       They  identify  the part of the subject that was partially matched. See
        the pcre2partial documentation for details of partial matching.
 
-       After  a  fully  successful match, the first pair of offsets identifies
-       the portion of the subject string that was matched by the  entire  pat-
-       tern.  The  next  pair is used for the first captured substring, and so
-       on. The value returned by pcre2_match() is one more  than  the  highest
-       numbered  pair  that  has been set. For example, if two substrings have
-       been captured, the returned value is 3. If there are no  captured  sub-
+       After a fully successful match, the first pair  of  offsets  identifies
+       the  portion  of the subject string that was matched by the entire pat-
+       tern. The next pair is used for the first captured  substring,  and  so
+       on.  The  value  returned by pcre2_match() is one more than the highest
+       numbered pair that has been set. For example, if  two  substrings  have
+       been  captured,  the returned value is 3. If there are no captured sub-
        strings, the return value from a successful match is 1, indicating that
        just the first pair of offsets has been set.
 
-       If a pattern uses the \K escape sequence within a  positive  assertion,
+       If  a  pattern uses the \K escape sequence within a positive assertion,
        the reported start of a successful match can be greater than the end of
-       the match.  For example, if the pattern  (?=ab\K)  is  matched  against
+       the  match.   For  example,  if the pattern (?=ab\K) is matched against
        "ab", the start and end offset values for the match are 2 and 0.
 
-       If  a  capturing subpattern group is matched repeatedly within a single
-       match operation, it is the last portion of the subject that it  matched
+       If a capturing subpattern group is matched repeatedly within  a  single
+       match  operation, it is the last portion of the subject that it matched
        that is returned.
 
        If the ovector is too small to hold all the captured substring offsets,
-       as much as possible is filled in, and the function returns a  value  of
-       zero.  If captured substrings are not of interest, pcre2_match() may be
+       as  much  as possible is filled in, and the function returns a value of
+       zero. If captured substrings are not of interest, pcre2_match() may  be
        called with a match data block whose ovector is of minimum length (that
        is, one pair).
 
-       It  is  possible for capturing subpattern number n+1 to match some part
+       It is possible for capturing subpattern number n+1 to match  some  part
        of the subject when subpattern n has not been used at all. For example,
-       if  the  string  "abc"  is  matched against the pattern (a|(z))(bc) the
+       if the string "abc" is matched  against  the  pattern  (a|(z))(bc)  the
        return from the function is 4, and subpatterns 1 and 3 are matched, but
-       2  is  not.  When  this happens, both values in the offset pairs corre-
+       2 is not. When this happens, both values in  the  offset  pairs  corre-
        sponding to unused subpatterns are set to PCRE2_UNSET.
 
-       Offset values that correspond to unused subpatterns at the end  of  the
-       expression  are  also  set  to  PCRE2_UNSET. For example, if the string
+       Offset  values  that correspond to unused subpatterns at the end of the
+       expression are also set to PCRE2_UNSET.  For  example,  if  the  string
        "abc" is matched against the pattern (abc)(x(yz)?)? subpatterns 2 and 3
-       are  not matched.  The return from the function is 2, because the high-
+       are not matched.  The return from the function is 2, because the  high-
        est used capturing subpattern number is 1. The offsets for for the sec-
-       ond  and  third  capturing  subpatterns  (assuming  the vector is large
+       ond and third capturing  subpatterns  (assuming  the  vector  is  large
        enough, of course) are set to PCRE2_UNSET.
 
        Elements in the ovector that do not correspond to capturing parentheses
        in the pattern are never changed. That is, if a pattern contains n cap-
        turing parentheses, no more than ovector[0] to ovector[2n+1] are set by
-       pcre2_match().  The  other  elements retain whatever values they previ-
+       pcre2_match(). The other elements retain whatever  values  they  previ-
        ously had.
 
 
@@ -2466,56 +2473,56 @@ OTHER INFORMATION ABOUT A MATCH
 
        PCRE2_SIZE pcre2_get_startchar(pcre2_match_data *match_data);
 
-       As well as the offsets in the ovector, other information about a  match
-       is  retained  in the match data block and can be retrieved by the above
-       functions in appropriate circumstances. If they  are  called  at  other
+       As  well as the offsets in the ovector, other information about a match
+       is retained in the match data block and can be retrieved by  the  above
+       functions  in  appropriate  circumstances.  If they are called at other
        times, the result is undefined.
 
-       After  a  successful match, a partial match (PCRE2_ERROR_PARTIAL), or a
-       failure to match (PCRE2_ERROR_NOMATCH), a (*MARK) name  may  be  avail-
-       able,  and  pcre2_get_mark() can be called. It returns a pointer to the
-       zero-terminated name, which is within the compiled  pattern.  Otherwise
-       NULL  is returned. The length of the (*MARK) name (excluding the termi-
-       nating zero) is stored in the code unit that  preceeds  the  name.  You
-       should  use  this  instead  of  relying  on the terminating zero if the
+       After a successful match, a partial match (PCRE2_ERROR_PARTIAL),  or  a
+       failure  to  match  (PCRE2_ERROR_NOMATCH), a (*MARK) name may be avail-
+       able, and pcre2_get_mark() can be called. It returns a pointer  to  the
+       zero-terminated  name,  which is within the compiled pattern. Otherwise
+       NULL is returned. The length of the (*MARK) name (excluding the  termi-
+       nating  zero)  is  stored  in the code unit that preceeds the name. You
+       should use this instead of relying  on  the  terminating  zero  if  the
        (*MARK) name might contain a binary zero.
 
        After a successful match, the (*MARK) name that is returned is the last
-       one  encountered  on the matching path through the pattern. After a "no
-       match" or a  partial  match,  the  last  encountered  (*MARK)  name  is
+       one encountered on the matching path through the pattern. After  a  "no
+       match"  or  a  partial  match,  the  last  encountered  (*MARK) name is
        returned. For example, consider this pattern:
 
          ^(*MARK:A)((*MARK:B)a|b)c
 
-       When  it  matches "bc", the returned mark is A. The B mark is "seen" in
-       the first branch of the group, but it is not on the matching  path.  On
-       the  other  hand,  when  this pattern fails to match "bx", the returned
+       When it matches "bc", the returned mark is A. The B mark is  "seen"  in
+       the  first  branch of the group, but it is not on the matching path. On
+       the other hand, when this pattern fails to  match  "bx",  the  returned
        mark is B.
 
-       After a successful match, a partial match, or one of  the  invalid  UTF
-       errors  (for example, PCRE2_ERROR_UTF8_ERR5), pcre2_get_startchar() can
+       After  a  successful  match, a partial match, or one of the invalid UTF
+       errors (for example, PCRE2_ERROR_UTF8_ERR5), pcre2_get_startchar()  can
        be called. After a successful or partial match it returns the code unit
-       offset  of  the character at which the match started. For a non-partial
-       match, this can be different to the value of ovector[0] if the  pattern
-       contains  the  \K escape sequence. After a partial match, however, this
-       value is always the same as ovector[0] because \K does not  affect  the
+       offset of the character at which the match started. For  a  non-partial
+       match,  this can be different to the value of ovector[0] if the pattern
+       contains the \K escape sequence. After a partial match,  however,  this
+       value  is  always the same as ovector[0] because \K does not affect the
        result of a partial match.
 
-       After  a UTF check failure, pcre2_get_startchar() can be used to obtain
+       After a UTF check failure, pcre2_get_startchar() can be used to  obtain
        the code unit offset of the invalid UTF character. Details are given in
        the pcre2unicode page.
 
 
 ERROR RETURNS FROM pcre2_match()
 
-       If  pcre2_match() fails, it returns a negative number. This can be con-
-       verted to a text string by calling the pcre2_get_error_message()  func-
-       tion  (see  "Obtaining a textual error message" below).  Negative error
-       codes are also returned by other functions,  and  are  documented  with
-       them.  The codes are given names in the header file. If UTF checking is
+       If pcre2_match() fails, it returns a negative number. This can be  con-
+       verted  to a text string by calling the pcre2_get_error_message() func-
+       tion (see "Obtaining a textual error message" below).   Negative  error
+       codes  are  also  returned  by other functions, and are documented with
+       them. The codes are given names in the header file. If UTF checking  is
        in force and an invalid UTF subject string is detected, one of a number
-       of  UTF-specific negative error codes is returned. Details are given in
-       the pcre2unicode page. The following are the other errors that  may  be
+       of UTF-specific negative error codes is returned. Details are given  in
+       the  pcre2unicode  page. The following are the other errors that may be
        returned by pcre2_match():
 
          PCRE2_ERROR_NOMATCH
@@ -2524,20 +2531,20 @@ ERROR RETURNS FROM pcre2_match()
 
          PCRE2_ERROR_PARTIAL
 
-       The  subject  string did not match, but it did match partially. See the
+       The subject string did not match, but it did match partially.  See  the
        pcre2partial documentation for details of partial matching.
 
          PCRE2_ERROR_BADMAGIC
 
        PCRE2 stores a 4-byte "magic number" at the start of the compiled code,
-       to  catch  the case when it is passed a junk pointer. This is the error
+       to catch the case when it is passed a junk pointer. This is  the  error
        that is returned when the magic number is not present.
 
          PCRE2_ERROR_BADMODE
 
-       This error is given when a compiled pattern is passed to a function  in
-       a  library  of a different code unit width, for example, a pattern com-
-       piled by the 8-bit library is passed to  a  16-bit  or  32-bit  library
+       This  error is given when a compiled pattern is passed to a function in
+       a library of a different code unit width, for example, a  pattern  com-
+       piled  by  the  8-bit  library  is passed to a 16-bit or 32-bit library
        function.
 
          PCRE2_ERROR_BADOFFSET
@@ -2551,15 +2558,15 @@ ERROR RETURNS FROM pcre2_match()
          PCRE2_ERROR_BADUTFOFFSET
 
        The UTF code unit sequence that was passed as a subject was checked and
-       found to be valid (the PCRE2_NO_UTF_CHECK option was not set), but  the
-       value  of startoffset did not point to the beginning of a UTF character
+       found  to be valid (the PCRE2_NO_UTF_CHECK option was not set), but the
+       value of startoffset did not point to the beginning of a UTF  character
        or the end of the subject.
 
          PCRE2_ERROR_CALLOUT
 
-       This error is never generated by pcre2_match() itself. It  is  provided
-       for  use  by  callout  functions  that  want  to cause pcre2_match() or
-       pcre2_callout_enumerate() to return a distinctive error code.  See  the
+       This  error  is never generated by pcre2_match() itself. It is provided
+       for use by callout  functions  that  want  to  cause  pcre2_match()  or
+       pcre2_callout_enumerate()  to  return a distinctive error code. See the
        pcre2callout documentation for details.
 
          PCRE2_ERROR_DEPTHLIMIT
@@ -2568,14 +2575,14 @@ ERROR RETURNS FROM pcre2_match()
 
          PCRE2_ERROR_INTERNAL
 
-       An  unexpected  internal error has occurred. This error could be caused
+       An unexpected internal error has occurred. This error could  be  caused
        by a bug in PCRE2 or by overwriting of the compiled pattern.
 
          PCRE2_ERROR_JIT_STACKLIMIT
 
-       This error is returned when a pattern  that  was  successfully  studied
-       using  JIT  is being matched, but the memory available for the just-in-
-       time processing stack is not large enough. See the pcre2jit  documenta-
+       This  error  is  returned  when a pattern that was successfully studied
+       using JIT is being matched, but the memory available for  the  just-in-
+       time  processing stack is not large enough. See the pcre2jit documenta-
        tion for more details.
 
          PCRE2_ERROR_MATCHLIMIT
@@ -2584,10 +2591,10 @@ ERROR RETURNS FROM pcre2_match()
 
          PCRE2_ERROR_NOMEMORY
 
-       If  a  pattern contains many nested backtracking points, heap memory is
-       used to remember them. This error is given when the  memory  allocation
-       function  (default  or  custom)  fails.  Note  that  a different error,
-       PCRE2_ERROR_HEAPLIMIT, is given if the amount of memory needed  exceeds
+       If a pattern contains many nested backtracking points, heap  memory  is
+       used  to  remember them. This error is given when the memory allocation
+       function (default or  custom)  fails.  Note  that  a  different  error,
+       PCRE2_ERROR_HEAPLIMIT,  is given if the amount of memory needed exceeds
        the heap limit.
 
          PCRE2_ERROR_NULL
@@ -2596,12 +2603,12 @@ ERROR RETURNS FROM pcre2_match()
 
          PCRE2_ERROR_RECURSELOOP
 
-       This  error  is  returned  when  pcre2_match() detects a recursion loop
-       within the pattern. Specifically, it means that either the  whole  pat-
+       This error is returned when  pcre2_match()  detects  a  recursion  loop
+       within  the  pattern. Specifically, it means that either the whole pat-
        tern or a subpattern has been called recursively for the second time at
-       the same position in the subject  string.  Some  simple  patterns  that
-       might  do  this are detected and faulted at compile time, but more com-
-       plicated cases, in particular mutual recursions between  two  different
+       the  same  position  in  the  subject string. Some simple patterns that
+       might do this are detected and faulted at compile time, but  more  com-
+       plicated  cases,  in particular mutual recursions between two different
        subpatterns, cannot be detected until matching is attempted.
 
 
@@ -2610,20 +2617,20 @@ OBTAINING A TEXTUAL ERROR MESSAGE
        int pcre2_get_error_message(int errorcode, PCRE2_UCHAR *buffer,
          PCRE2_SIZE bufflen);
 
-       A  text  message  for  an  error code from any PCRE2 function (compile,
-       match, or auxiliary) can be obtained  by  calling  pcre2_get_error_mes-
-       sage().  The  code  is passed as the first argument, with the remaining
-       two arguments specifying a code unit buffer  and  its  length  in  code
-       units,  into  which the text message is placed. The message is returned
-       in code units of the appropriate width for the library  that  is  being
+       A text message for an error code  from  any  PCRE2  function  (compile,
+       match,  or  auxiliary)  can be obtained by calling pcre2_get_error_mes-
+       sage(). The code is passed as the first argument,  with  the  remaining
+       two  arguments  specifying  a  code  unit buffer and its length in code
+       units, into which the text message is placed. The message  is  returned
+       in  code  units  of the appropriate width for the library that is being
        used.
 
-       The  returned message is terminated with a trailing zero, and the func-
-       tion returns the number of code  units  used,  excluding  the  trailing
+       The returned message is terminated with a trailing zero, and the  func-
+       tion  returns  the  number  of  code units used, excluding the trailing
        zero.  If  the  error  number  is  unknown,  the  negative  error  code
-       PCRE2_ERROR_BADDATA is returned. If the buffer is too small,  the  mes-
-       sage  is  truncated  (but still with a trailing zero), and the negative
-       error code PCRE2_ERROR_NOMEMORY is returned.  None of the messages  are
+       PCRE2_ERROR_BADDATA  is  returned. If the buffer is too small, the mes-
+       sage is truncated (but still with a trailing zero),  and  the  negative
+       error  code PCRE2_ERROR_NOMEMORY is returned.  None of the messages are
        very long; a buffer size of 120 code units is ample.
 
 
@@ -2642,39 +2649,39 @@ EXTRACTING CAPTURED SUBSTRINGS BY NUMBER
 
        void pcre2_substring_free(PCRE2_UCHAR *buffer);
 
-       Captured  substrings  can  be accessed directly by using the ovector as
+       Captured substrings can be accessed directly by using  the  ovector  as
        described above.  For convenience, auxiliary functions are provided for
-       extracting   captured  substrings  as  new,  separate,  zero-terminated
+       extracting  captured  substrings  as  new,  separate,   zero-terminated
        strings. A substring that contains a binary zero is correctly extracted
-       and  has  a  further  zero  added on the end, but the result is not, of
+       and has a further zero added on the end, but  the  result  is  not,  of
        course, a C string.
 
        The functions in this section identify substrings by number. The number
        zero refers to the entire matched substring, with higher numbers refer-
-       ring to substrings captured by parenthesized groups.  After  a  partial
-       match,  only  substring  zero  is  available. An attempt to extract any
-       other substring gives the error PCRE2_ERROR_PARTIAL. The  next  section
+       ring  to  substrings  captured by parenthesized groups. After a partial
+       match, only substring zero is available.  An  attempt  to  extract  any
+       other  substring  gives the error PCRE2_ERROR_PARTIAL. The next section
        describes similar functions for extracting captured substrings by name.
 
-       If  a  pattern uses the \K escape sequence within a positive assertion,
+       If a pattern uses the \K escape sequence within a  positive  assertion,
        the reported start of a successful match can be greater than the end of
-       the  match.   For  example,  if the pattern (?=ab\K) is matched against
-       "ab", the start and end offset values for the match are  2  and  0.  In
-       this  situation,  calling  these functions with a zero substring number
+       the match.  For example, if the pattern  (?=ab\K)  is  matched  against
+       "ab",  the  start  and  end offset values for the match are 2 and 0. In
+       this situation, calling these functions with a  zero  substring  number
        extracts a zero-length empty string.
 
-       You can find the length in code units of a captured  substring  without
-       extracting  it  by calling pcre2_substring_length_bynumber(). The first
-       argument is a pointer to the match data block, the second is the  group
-       number,  and the third is a pointer to a variable into which the length
-       is placed. If you just want to know whether or not  the  substring  has
+       You  can  find the length in code units of a captured substring without
+       extracting it by calling pcre2_substring_length_bynumber().  The  first
+       argument  is a pointer to the match data block, the second is the group
+       number, and the third is a pointer to a variable into which the  length
+       is  placed.  If  you just want to know whether or not the substring has
        been captured, you can pass the third argument as NULL.
 
-       The  pcre2_substring_copy_bynumber()  function  copies  a captured sub-
-       string into a supplied buffer,  whereas  pcre2_substring_get_bynumber()
-       copies  it  into  new memory, obtained using the same memory allocation
-       function that was used for the match data block. The  first  two  argu-
-       ments  of  these  functions are a pointer to the match data block and a
+       The pcre2_substring_copy_bynumber() function  copies  a  captured  sub-
+       string  into  a supplied buffer, whereas pcre2_substring_get_bynumber()
+       copies it into new memory, obtained using the  same  memory  allocation
+       function  that  was  used for the match data block. The first two argu-
+       ments of these functions are a pointer to the match data  block  and  a
        capturing group number.
 
        The final arguments of pcre2_substring_copy_bynumber() are a pointer to
@@ -2683,25 +2690,25 @@ EXTRACTING CAPTURED SUBSTRINGS BY NUMBER
        for the extracted substring, excluding the terminating zero.
 
        For pcre2_substring_get_bynumber() the third and fourth arguments point
-       to variables that are updated with a pointer to the new memory and  the
-       number  of  code units that comprise the substring, again excluding the
-       terminating zero. When the substring is no longer  needed,  the  memory
+       to  variables that are updated with a pointer to the new memory and the
+       number of code units that comprise the substring, again  excluding  the
+       terminating  zero.  When  the substring is no longer needed, the memory
        should be freed by calling pcre2_substring_free().
 
-       The  return  value  from  all these functions is zero for success, or a
-       negative error code. If the pattern match  failed,  the  match  failure
-       code  is  returned.   If  a  substring number greater than zero is used
-       after a partial match, PCRE2_ERROR_PARTIAL is returned. Other  possible
+       The return value from all these functions is zero  for  success,  or  a
+       negative  error  code.  If  the pattern match failed, the match failure
+       code is returned.  If a substring number  greater  than  zero  is  used
+       after  a partial match, PCRE2_ERROR_PARTIAL is returned. Other possible
        error codes are:
 
          PCRE2_ERROR_NOMEMORY
 
-       The  buffer  was  too small for pcre2_substring_copy_bynumber(), or the
+       The buffer was too small for  pcre2_substring_copy_bynumber(),  or  the
        attempt to get memory failed for pcre2_substring_get_bynumber().
 
          PCRE2_ERROR_NOSUBSTRING
 
-       There is no substring with that number in the  pattern,  that  is,  the
+       There  is  no  substring  with that number in the pattern, that is, the
        number is greater than the number of capturing parentheses.
 
          PCRE2_ERROR_UNAVAILABLE
@@ -2712,8 +2719,8 @@ EXTRACTING CAPTURED SUBSTRINGS BY NUMBER
 
          PCRE2_ERROR_UNSET
 
-       The  substring  did  not  participate in the match. For example, if the
-       pattern is (abc)|(def) and the subject is "def", and the  ovector  con-
+       The substring did not participate in the match.  For  example,  if  the
+       pattern  is  (abc)|(def) and the subject is "def", and the ovector con-
        tains at least two capturing slots, substring number 1 is unset.
 
 
@@ -2724,32 +2731,32 @@ EXTRACTING A LIST OF ALL CAPTURED SUBSTRINGS
 
        void pcre2_substring_list_free(PCRE2_SPTR *list);
 
-       The  pcre2_substring_list_get()  function  extracts  all available sub-
-       strings and builds a list of pointers to  them.  It  also  (optionally)
-       builds  a  second  list  that  contains  their lengths (in code units),
+       The pcre2_substring_list_get() function  extracts  all  available  sub-
+       strings  and  builds  a  list of pointers to them. It also (optionally)
+       builds a second list that  contains  their  lengths  (in  code  units),
        excluding a terminating zero that is added to each of them. All this is
        done in a single block of memory that is obtained using the same memory
        allocation function that was used to get the match data block.
 
-       This function must be called only after a successful match.  If  called
+       This  function  must be called only after a successful match. If called
        after a partial match, the error code PCRE2_ERROR_PARTIAL is returned.
 
-       The  address of the memory block is returned via listptr, which is also
+       The address of the memory block is returned via listptr, which is  also
        the start of the list of string pointers. The end of the list is marked
-       by  a  NULL pointer. The address of the list of lengths is returned via
-       lengthsptr. If your strings do not contain binary zeros and you do  not
+       by a NULL pointer. The address of the list of lengths is  returned  via
+       lengthsptr.  If your strings do not contain binary zeros and you do not
        therefore need the lengths, you may supply NULL as the lengthsptr argu-
-       ment to disable the creation of a list of lengths.  The  yield  of  the
-       function  is zero if all went well, or PCRE2_ERROR_NOMEMORY if the mem-
-       ory block could not be obtained. When the list is no longer needed,  it
+       ment  to  disable  the  creation of a list of lengths. The yield of the
+       function is zero if all went well, or PCRE2_ERROR_NOMEMORY if the  mem-
+       ory  block could not be obtained. When the list is no longer needed, it
        should be freed by calling pcre2_substring_list_free().
 
        If this function encounters a substring that is unset, which can happen
-       when capturing subpattern number n+1 matches some part of the  subject,
-       but  subpattern n has not been used at all, it returns an empty string.
-       This can be distinguished  from  a  genuine  zero-length  substring  by
+       when  capturing subpattern number n+1 matches some part of the subject,
+       but subpattern n has not been used at all, it returns an empty  string.
+       This  can  be  distinguished  from  a  genuine zero-length substring by
        inspecting  the  appropriate  offset  in  the  ovector,  which  contain
-       PCRE2_UNSET  for   unset   substrings,   or   by   calling   pcre2_sub-
+       PCRE2_UNSET   for   unset   substrings,   or   by   calling  pcre2_sub-
        string_length_bynumber().
 
 
@@ -2769,39 +2776,39 @@ EXTRACTING CAPTURED SUBSTRINGS BY NAME
 
        void pcre2_substring_free(PCRE2_UCHAR *buffer);
 
-       To  extract a substring by name, you first have to find associated num-
+       To extract a substring by name, you first have to find associated  num-
        ber.  For example, for this pattern:
 
          (a+)b(?\d+)...
 
        the number of the subpattern called "xxx" is 2. If the name is known to
-       be  unique  (PCRE2_DUPNAMES  was not set), you can find the number from
+       be unique (PCRE2_DUPNAMES was not set), you can find  the  number  from
        the name by calling pcre2_substring_number_from_name(). The first argu-
-       ment  is the compiled pattern, and the second is the name. The yield of
+       ment is the compiled pattern, and the second is the name. The yield  of
        the function is the subpattern number, PCRE2_ERROR_NOSUBSTRING if there
-       is  no  subpattern  of  that  name, or PCRE2_ERROR_NOUNIQUESUBSTRING if
-       there is more than one subpattern of that name. Given the  number,  you
-       can  extract the substring directly from the ovector, or use one of the
+       is no subpattern of  that  name,  or  PCRE2_ERROR_NOUNIQUESUBSTRING  if
+       there  is  more than one subpattern of that name. Given the number, you
+       can extract the substring directly from the ovector, or use one of  the
        "bynumber" functions described above.
 
-       For convenience, there are also "byname" functions that  correspond  to
-       the  "bynumber"  functions,  the  only difference being that the second
-       argument is a name instead of a number. If PCRE2_DUPNAMES  is  set  and
+       For  convenience,  there are also "byname" functions that correspond to
+       the "bynumber" functions, the only difference  being  that  the  second
+       argument  is  a  name instead of a number. If PCRE2_DUPNAMES is set and
        there are duplicate names, these functions scan all the groups with the
        given name, and return the first named string that is set.
 
-       If there are no groups with the given name, PCRE2_ERROR_NOSUBSTRING  is
-       returned.  If  all  groups  with the name have numbers that are greater
-       than the number of slots in  the  ovector,  PCRE2_ERROR_UNAVAILABLE  is
-       returned.  If  there  is at least one group with a slot in the ovector,
+       If  there are no groups with the given name, PCRE2_ERROR_NOSUBSTRING is
+       returned. If all groups with the name have  numbers  that  are  greater
+       than  the  number  of  slots in the ovector, PCRE2_ERROR_UNAVAILABLE is
+       returned. If there is at least one group with a slot  in  the  ovector,
        but no group is found to be set, PCRE2_ERROR_UNSET is returned.
 
        Warning: If the pattern uses the (?| feature to set up multiple subpat-
-       terns  with  the  same number, as described in the section on duplicate
-       subpattern numbers in the pcre2pattern page, you cannot  use  names  to
-       distinguish  the  different subpatterns, because names are not included
-       in the compiled code. The matching process uses only numbers. For  this
-       reason,  the  use of different names for subpatterns of the same number
+       terns with the same number, as described in the  section  on  duplicate
+       subpattern  numbers  in  the pcre2pattern page, you cannot use names to
+       distinguish the different subpatterns, because names are  not  included
+       in  the compiled code. The matching process uses only numbers. For this
+       reason, the use of different names for subpatterns of the  same  number
        causes an error at compile time.
 
 
@@ -2814,52 +2821,52 @@ CREATING A NEW STRING WITH SUBSTITUTIONS
          PCRE2_SIZE rlength, PCRE2_UCHAR *outputbufferP,
          PCRE2_SIZE *outlengthptr);
 
-       This function calls pcre2_match() and then makes a copy of the  subject
-       string  in  outputbuffer,  replacing the part that was matched with the
-       replacement string, whose length is supplied in rlength.  This  can  be
+       This  function calls pcre2_match() and then makes a copy of the subject
+       string in outputbuffer, replacing the part that was  matched  with  the
+       replacement  string,  whose  length is supplied in rlength. This can be
        given as PCRE2_ZERO_TERMINATED for a zero-terminated string. Matches in
-       which a \K item in a lookahead in the pattern causes the match  to  end
+       which  a  \K item in a lookahead in the pattern causes the match to end
        before it starts are not supported, and give rise to an error return.
 
-       The  first  seven  arguments  of pcre2_substitute() are the same as for
+       The first seven arguments of pcre2_substitute() are  the  same  as  for
        pcre2_match(), except that the partial matching options are not permit-
-       ted,  and  match_data may be passed as NULL, in which case a match data
-       block is obtained and freed within this function, using memory  manage-
-       ment  functions from the match context, if provided, or else those that
+       ted, and match_data may be passed as NULL, in which case a  match  data
+       block  is obtained and freed within this function, using memory manage-
+       ment functions from the match context, if provided, or else those  that
        were used to allocate memory for the compiled code.
 
-       The outlengthptr argument must point to a variable  that  contains  the
-       length,  in  code  units, of the output buffer. If the function is suc-
-       cessful, the value is updated to contain the length of the new  string,
+       The  outlengthptr  argument  must point to a variable that contains the
+       length, in code units, of the output buffer. If the  function  is  suc-
+       cessful,  the value is updated to contain the length of the new string,
        excluding the trailing zero that is automatically added.
 
-       If  the  function  is  not  successful,  the value set via outlengthptr
-       depends on the type of error. For  syntax  errors  in  the  replacement
-       string,  the  value  is  the offset in the replacement string where the
-       error was detected. For other  errors,  the  value  is  PCRE2_UNSET  by
-       default.  This  includes the case of the output buffer being too small,
-       unless PCRE2_SUBSTITUTE_OVERFLOW_LENGTH is set (see  below),  in  which
-       case  the  value  is the minimum length needed, including space for the
-       trailing zero. Note that in  order  to  compute  the  required  length,
-       pcre2_substitute()  has  to  simulate  all  the  matching  and copying,
+       If the function is not  successful,  the  value  set  via  outlengthptr
+       depends  on  the  type  of  error. For syntax errors in the replacement
+       string, the value is the offset in the  replacement  string  where  the
+       error  was  detected.  For  other  errors,  the value is PCRE2_UNSET by
+       default. This includes the case of the output buffer being  too  small,
+       unless  PCRE2_SUBSTITUTE_OVERFLOW_LENGTH  is  set (see below), in which
+       case the value is the minimum length needed, including  space  for  the
+       trailing  zero.  Note  that  in  order  to compute the required length,
+       pcre2_substitute() has  to  simulate  all  the  matching  and  copying,
        instead of giving an error return as soon as the buffer overflows. Note
        also that the length is in code units, not bytes.
 
-       In  the replacement string, which is interpreted as a UTF string in UTF
-       mode, and is checked for UTF  validity  unless  the  PCRE2_NO_UTF_CHECK
+       In the replacement string, which is interpreted as a UTF string in  UTF
+       mode,  and  is  checked  for UTF validity unless the PCRE2_NO_UTF_CHECK
        option is set, a dollar character is an escape character that can spec-
-       ify the insertion of characters from capturing groups or (*MARK)  items
+       ify  the insertion of characters from capturing groups or (*MARK) items
        in the pattern. The following forms are always recognized:
 
          $$                  insert a dollar character
          $ or ${}      insert the contents of group 
          $*MARK or ${*MARK}  insert the name of the last (*MARK) encountered
 
-       Either  a  group  number  or  a  group name can be given for . Curly
-       brackets are required only if the following character would  be  inter-
+       Either a group number or a group name  can  be  given  for  .  Curly
+       brackets  are  required only if the following character would be inter-
        preted as part of the number or name. The number may be zero to include
-       the entire matched string.   For  example,  if  the  pattern  a(b)c  is
-       matched  with "=abc=" and the replacement string "+$1$0$1+", the result
+       the  entire  matched  string.   For  example,  if  the pattern a(b)c is
+       matched with "=abc=" and the replacement string "+$1$0$1+", the  result
        is "=+babcb+=".
 
        The facility for inserting a (*MARK) name can be used to perform simple
@@ -2869,92 +2876,92 @@ CREATING A NEW STRING WITH SUBSTITUTIONS
              apple lemon
           2: pear orange
 
-       As  well as the usual options for pcre2_match(), a number of additional
+       As well as the usual options for pcre2_match(), a number of  additional
        options can be set in the options argument.
 
        PCRE2_SUBSTITUTE_GLOBAL causes the function to iterate over the subject
-       string,  replacing  every  matching substring. If this is not set, only
-       the first matching substring is replaced. If any matched substring  has
-       zero  length, after the substitution has happened, an attempt to find a
-       non-empty match at the same position is performed. If this is not  suc-
-       cessful,  the current position is advanced by one character except when
-       CRLF is a valid newline sequence and the next two  characters  are  CR,
+       string, replacing every matching substring. If this is  not  set,  only
+       the  first matching substring is replaced. If any matched substring has
+       zero length, after the substitution has happened, an attempt to find  a
+       non-empty  match at the same position is performed. If this is not suc-
+       cessful, the current position is advanced by one character except  when
+       CRLF  is  a  valid newline sequence and the next two characters are CR,
        LF. In this case, the current position is advanced by two characters.
 
-       PCRE2_SUBSTITUTE_OVERFLOW_LENGTH  changes  what happens when the output
+       PCRE2_SUBSTITUTE_OVERFLOW_LENGTH changes what happens when  the  output
        buffer is too small. The default action is to return PCRE2_ERROR_NOMEM-
-       ORY  immediately.  If  this  option is set, however, pcre2_substitute()
+       ORY immediately. If this option  is  set,  however,  pcre2_substitute()
        continues to go through the motions of matching and substituting (with-
-       out,  of course, writing anything) in order to compute the size of buf-
-       fer that is needed. This value is  passed  back  via  the  outlengthptr
-       variable,    with    the   result   of   the   function   still   being
+       out, of course, writing anything) in order to compute the size of  buf-
+       fer  that  is  needed.  This  value is passed back via the outlengthptr
+       variable,   with   the   result   of   the   function    still    being
        PCRE2_ERROR_NOMEMORY.
 
-       Passing a buffer size of zero is a permitted way  of  finding  out  how
-       much  memory  is needed for given substitution. However, this does mean
+       Passing  a  buffer  size  of zero is a permitted way of finding out how
+       much memory is needed for given substitution. However, this  does  mean
        that the entire operation is carried out twice. Depending on the appli-
-       cation,  it  may  be more efficient to allocate a large buffer and free
-       the  excess  afterwards,  instead   of   using   PCRE2_SUBSTITUTE_OVER-
+       cation, it may be more efficient to allocate a large  buffer  and  free
+       the   excess   afterwards,   instead  of  using  PCRE2_SUBSTITUTE_OVER-
        FLOW_LENGTH.
 
-       PCRE2_SUBSTITUTE_UNKNOWN_UNSET  causes  references  to capturing groups
-       that do not appear in the pattern to be treated as unset  groups.  This
-       option  should  be  used  with  care, because it means that a typo in a
-       group name or  number  no  longer  causes  the  PCRE2_ERROR_NOSUBSTRING
+       PCRE2_SUBSTITUTE_UNKNOWN_UNSET causes references  to  capturing  groups
+       that  do  not appear in the pattern to be treated as unset groups. This
+       option should be used with care, because it means  that  a  typo  in  a
+       group  name  or  number  no  longer  causes the PCRE2_ERROR_NOSUBSTRING
        error.
 
-       PCRE2_SUBSTITUTE_UNSET_EMPTY  causes  unset capturing groups (including
+       PCRE2_SUBSTITUTE_UNSET_EMPTY causes unset capturing  groups  (including
        unknown  groups  when  PCRE2_SUBSTITUTE_UNKNOWN_UNSET  is  set)  to  be
-       treated  as  empty  strings  when  inserted as described above. If this
-       option is not set, an attempt to  insert  an  unset  group  causes  the
-       PCRE2_ERROR_UNSET  error.  This  option does not influence the extended
+       treated as empty strings when inserted  as  described  above.  If  this
+       option  is  not  set,  an  attempt  to insert an unset group causes the
+       PCRE2_ERROR_UNSET error. This option does not  influence  the  extended
        substitution syntax described below.
 
-       PCRE2_SUBSTITUTE_EXTENDED causes extra processing to be applied to  the
-       replacement  string.  Without this option, only the dollar character is
-       special, and only the group insertion forms  listed  above  are  valid.
+       PCRE2_SUBSTITUTE_EXTENDED  causes extra processing to be applied to the
+       replacement string. Without this option, only the dollar  character  is
+       special,  and  only  the  group insertion forms listed above are valid.
        When PCRE2_SUBSTITUTE_EXTENDED is set, two things change:
 
-       Firstly,  backslash in a replacement string is interpreted as an escape
+       Firstly, backslash in a replacement string is interpreted as an  escape
        character. The usual forms such as \n or \x{ddd} can be used to specify
-       particular  character codes, and backslash followed by any non-alphanu-
-       meric character quotes that character. Extended quoting  can  be  coded
+       particular character codes, and backslash followed by any  non-alphanu-
+       meric  character  quotes  that character. Extended quoting can be coded
        using \Q...\E, exactly as in pattern strings.
 
-       There  are  also four escape sequences for forcing the case of inserted
-       letters.  The insertion mechanism has three states:  no  case  forcing,
+       There are also four escape sequences for forcing the case  of  inserted
+       letters.   The  insertion  mechanism has three states: no case forcing,
        force upper case, and force lower case. The escape sequences change the
        current state: \U and \L change to upper or lower case forcing, respec-
-       tively,  and  \E (when not terminating a \Q quoted sequence) reverts to
-       no case forcing. The sequences \u and \l force the next  character  (if
-       it  is  a  letter)  to  upper or lower case, respectively, and then the
+       tively, and \E (when not terminating a \Q quoted sequence)  reverts  to
+       no  case  forcing. The sequences \u and \l force the next character (if
+       it is a letter) to upper or lower  case,  respectively,  and  then  the
        state automatically reverts to no case forcing. Case forcing applies to
        all inserted  characters, including those from captured groups and let-
        ters within \Q...\E quoted sequences.
 
        Note that case forcing sequences such as \U...\E do not nest. For exam-
-       ple,  the  result of processing "\Uaa\LBB\Ecc\E" is "AAbbcc"; the final
+       ple, the result of processing "\Uaa\LBB\Ecc\E" is "AAbbcc";  the  final
        \E has no effect.
 
-       The second effect of setting PCRE2_SUBSTITUTE_EXTENDED is to  add  more
-       flexibility  to  group substitution. The syntax is similar to that used
+       The  second  effect of setting PCRE2_SUBSTITUTE_EXTENDED is to add more
+       flexibility to group substitution. The syntax is similar to  that  used
        by Bash:
 
          ${:-}
          ${:+:}
 
-       As before,  may be a group number or a name. The first  form  speci-
-       fies  a  default  value. If group  is set, its value is inserted; if
-       not,  is expanded and the  result  inserted.  The  second  form
-       specifies  strings that are expanded and inserted when group  is set
-       or unset, respectively. The first form is just a  convenient  shorthand
+       As  before,   may be a group number or a name. The first form speci-
+       fies a default value. If group  is set, its value  is  inserted;  if
+       not,    is  expanded  and  the result inserted. The second form
+       specifies strings that are expanded and inserted when group  is  set
+       or  unset,  respectively. The first form is just a convenient shorthand
        for
 
          ${:+${}:}
 
-       Backslash  can  be  used to escape colons and closing curly brackets in
-       the replacement strings. A change of the case forcing  state  within  a
-       replacement  string  remains  in  force  afterwards,  as  shown in this
+       Backslash can be used to escape colons and closing  curly  brackets  in
+       the  replacement  strings.  A change of the case forcing state within a
+       replacement string remains  in  force  afterwards,  as  shown  in  this
        pcre2test example:
 
          /(some)?(body)/substitute_extended,replace=${1:+\U:\L}HeLLo
@@ -2963,41 +2970,41 @@ CREATING A NEW STRING WITH SUBSTITUTIONS
              somebody
           1: HELLO
 
-       The PCRE2_SUBSTITUTE_UNSET_EMPTY option does not affect these  extended
-       substitutions.   However,   PCRE2_SUBSTITUTE_UNKNOWN_UNSET  does  cause
+       The  PCRE2_SUBSTITUTE_UNSET_EMPTY option does not affect these extended
+       substitutions.  However,  PCRE2_SUBSTITUTE_UNKNOWN_UNSET   does   cause
        unknown groups in the extended syntax forms to be treated as unset.
 
-       If successful, pcre2_substitute() returns the  number  of  replacements
+       If  successful,  pcre2_substitute()  returns the number of replacements
        that were made. This may be zero if no matches were found, and is never
        greater than 1 unless PCRE2_SUBSTITUTE_GLOBAL is set.
 
        In the event of an error, a negative error code is returned. Except for
-       PCRE2_ERROR_NOMATCH    (which   is   never   returned),   errors   from
+       PCRE2_ERROR_NOMATCH   (which   is   never   returned),   errors    from
        pcre2_match() are passed straight back.
 
        PCRE2_ERROR_NOSUBSTRING is returned for a non-existent substring inser-
        tion, unless PCRE2_SUBSTITUTE_UNKNOWN_UNSET is set.
 
        PCRE2_ERROR_UNSET is returned for an unset substring insertion (includ-
-       ing an unknown substring when  PCRE2_SUBSTITUTE_UNKNOWN_UNSET  is  set)
+       ing  an  unknown  substring when PCRE2_SUBSTITUTE_UNKNOWN_UNSET is set)
        when  the  simple  (non-extended)  syntax  is  used  and  PCRE2_SUBSTI-
        TUTE_UNSET_EMPTY is not set.
 
-       PCRE2_ERROR_NOMEMORY is returned  if  the  output  buffer  is  not  big
+       PCRE2_ERROR_NOMEMORY  is  returned  if  the  output  buffer  is not big
        enough. If the PCRE2_SUBSTITUTE_OVERFLOW_LENGTH option is set, the size
-       of buffer that is needed is returned via outlengthptr. Note  that  this
+       of  buffer  that is needed is returned via outlengthptr. Note that this
        does not happen by default.
 
-       PCRE2_ERROR_BADREPLACEMENT  is  used for miscellaneous syntax errors in
+       PCRE2_ERROR_BADREPLACEMENT is used for miscellaneous syntax  errors  in
        the   replacement   string,   with   more   particular   errors   being
-       PCRE2_ERROR_BADREPESCAPE  (invalid  escape  sequence), PCRE2_ERROR_REP-
-       MISSING_BRACE (closing curly bracket not found),  PCRE2_BADSUBSTITUTION
-       (syntax  error in extended group substitution), and PCRE2_BADSUBPATTERN
-       (the pattern match ended before it started, which can happen if  \K  is
+       PCRE2_ERROR_BADREPESCAPE (invalid  escape  sequence),  PCRE2_ERROR_REP-
+       MISSING_BRACE  (closing curly bracket not found), PCRE2_BADSUBSTITUTION
+       (syntax error in extended group substitution), and  PCRE2_BADSUBPATTERN
+       (the  pattern  match ended before it started, which can happen if \K is
        used in an assertion).
 
        As for all PCRE2 errors, a text message that describes the error can be
-       obtained  by  calling  the  pcre2_get_error_message()   function   (see
+       obtained   by   calling  the  pcre2_get_error_message()  function  (see
        "Obtaining a textual error message" above).
 
 
@@ -3006,56 +3013,56 @@ DUPLICATE SUBPATTERN NAMES
        int pcre2_substring_nametable_scan(const pcre2_code *code,
          PCRE2_SPTR name, PCRE2_SPTR *first, PCRE2_SPTR *last);
 
-       When  a  pattern  is compiled with the PCRE2_DUPNAMES option, names for
-       subpatterns are not required to be unique. Duplicate names  are  always
-       allowed  for subpatterns with the same number, created by using the (?|
-       feature. Indeed, if such subpatterns are named, they  are  required  to
+       When a pattern is compiled with the PCRE2_DUPNAMES  option,  names  for
+       subpatterns  are  not required to be unique. Duplicate names are always
+       allowed for subpatterns with the same number, created by using the  (?|
+       feature.  Indeed,  if  such subpatterns are named, they are required to
        use the same names.
 
        Normally, patterns with duplicate names are such that in any one match,
-       only one of the named subpatterns participates. An example is shown  in
+       only  one of the named subpatterns participates. An example is shown in
        the pcre2pattern documentation.
 
-       When   duplicates   are   present,   pcre2_substring_copy_byname()  and
-       pcre2_substring_get_byname() return the first  substring  corresponding
-       to   the   given   name   that   is  set.  Only  if  none  are  set  is
-       PCRE2_ERROR_UNSET is returned.  The  pcre2_substring_number_from_name()
+       When  duplicates   are   present,   pcre2_substring_copy_byname()   and
+       pcre2_substring_get_byname()  return  the first substring corresponding
+       to  the  given  name  that  is  set.  Only   if   none   are   set   is
+       PCRE2_ERROR_UNSET  is  returned. The pcre2_substring_number_from_name()
        function returns the error PCRE2_ERROR_NOUNIQUESUBSTRING when there are
        duplicate names.
 
-       If you want to get full details of all captured substrings for a  given
-       name,  you  must use the pcre2_substring_nametable_scan() function. The
-       first argument is the compiled pattern, and the second is the name.  If
-       the  third  and fourth arguments are NULL, the function returns a group
+       If  you want to get full details of all captured substrings for a given
+       name, you must use the pcre2_substring_nametable_scan()  function.  The
+       first  argument is the compiled pattern, and the second is the name. If
+       the third and fourth arguments are NULL, the function returns  a  group
        number for a unique name, or PCRE2_ERROR_NOUNIQUESUBSTRING otherwise.
 
        When the third and fourth arguments are not NULL, they must be pointers
-       to  variables  that are updated by the function. After it has run, they
+       to variables that are updated by the function. After it has  run,  they
        point to the first and last entries in the name-to-number table for the
-       given  name,  and the function returns the length of each entry in code
-       units. In both cases, PCRE2_ERROR_NOSUBSTRING is returned if there  are
+       given name, and the function returns the length of each entry  in  code
+       units.  In both cases, PCRE2_ERROR_NOSUBSTRING is returned if there are
        no entries for the given name.
 
        The format of the name table is described above in the section entitled
-       Information about a pattern. Given all the  relevant  entries  for  the
-       name,  you  can  extract  each of their numbers, and hence the captured
+       Information  about  a  pattern.  Given all the relevant entries for the
+       name, you can extract each of their numbers,  and  hence  the  captured
        data.
 
 
 FINDING ALL POSSIBLE MATCHES AT ONE POSITION
 
-       The traditional matching function uses a  similar  algorithm  to  Perl,
-       which  stops when it finds the first match at a given point in the sub-
+       The  traditional  matching  function  uses a similar algorithm to Perl,
+       which stops when it finds the first match at a given point in the  sub-
        ject. If you want to find all possible matches, or the longest possible
-       match  at  a  given  position,  consider using the alternative matching
-       function (see below) instead. If you cannot use the  alternative  func-
+       match at a given position,  consider  using  the  alternative  matching
+       function  (see  below) instead. If you cannot use the alternative func-
        tion, you can kludge it up by making use of the callout facility, which
        is described in the pcre2callout documentation.
 
        What you have to do is to insert a callout right at the end of the pat-
-       tern.   When your callout function is called, extract and save the cur-
-       rent matched substring. Then return 1, which  forces  pcre2_match()  to
-       backtrack  and  try other alternatives. Ultimately, when it runs out of
+       tern.  When your callout function is called, extract and save the  cur-
+       rent  matched  substring.  Then return 1, which forces pcre2_match() to
+       backtrack and try other alternatives. Ultimately, when it runs  out  of
        matches, pcre2_match() will yield PCRE2_ERROR_NOMATCH.
 
 
@@ -3067,26 +3074,26 @@ MATCHING A PATTERN: THE ALTERNATIVE FUNCTION
          pcre2_match_context *mcontext,
          int *workspace, PCRE2_SIZE wscount);
 
-       The function pcre2_dfa_match() is called  to  match  a  subject  string
-       against  a  compiled pattern, using a matching algorithm that scans the
+       The  function  pcre2_dfa_match()  is  called  to match a subject string
+       against a compiled pattern, using a matching algorithm that  scans  the
        subject string just once (not counting lookaround assertions), and does
-       not  backtrack.  This has different characteristics to the normal algo-
-       rithm, and is not compatible with Perl. Some of the features  of  PCRE2
-       patterns  are  not  supported.  Nevertheless, there are times when this
-       kind of matching can be useful. For a discussion of  the  two  matching
+       not backtrack.  This has different characteristics to the normal  algo-
+       rithm,  and  is not compatible with Perl. Some of the features of PCRE2
+       patterns are not supported.  Nevertheless, there are  times  when  this
+       kind  of  matching  can be useful. For a discussion of the two matching
        algorithms, and a list of features that pcre2_dfa_match() does not sup-
        port, see the pcre2matching documentation.
 
-       The arguments for the pcre2_dfa_match() function are the  same  as  for
+       The  arguments  for  the pcre2_dfa_match() function are the same as for
        pcre2_match(), plus two extras. The ovector within the match data block
        is used in a different way, and this is described below. The other com-
-       mon  arguments  are used in the same way as for pcre2_match(), so their
+       mon arguments are used in the same way as for pcre2_match(),  so  their
        description is not repeated here.
 
-       The two additional arguments provide workspace for  the  function.  The
-       workspace  vector  should  contain at least 20 elements. It is used for
+       The  two  additional  arguments provide workspace for the function. The
+       workspace vector should contain at least 20 elements. It  is  used  for
        keeping  track  of  multiple  paths  through  the  pattern  tree.  More
-       workspace  is needed for patterns and subjects where there are a lot of
+       workspace is needed for patterns and subjects where there are a lot  of
        potential matches.
 
        Here is an example of a simple call to pcre2_dfa_match():
@@ -3106,45 +3113,45 @@ MATCHING A PATTERN: THE ALTERNATIVE FUNCTION
 
    Option bits for pcre_dfa_match()
 
-       The unused bits of the options argument for pcre2_dfa_match()  must  be
-       zero.  The  only  bits that may be set are PCRE2_ANCHORED, PCRE2_ENDAN-
-       CHORED,       PCRE2_NOTBOL,        PCRE2_NOTEOL,        PCRE2_NOTEMPTY,
+       The  unused  bits of the options argument for pcre2_dfa_match() must be
+       zero. The only bits that may be set  are  PCRE2_ANCHORED,  PCRE2_ENDAN-
+       CHORED,        PCRE2_NOTBOL,        PCRE2_NOTEOL,       PCRE2_NOTEMPTY,
        PCRE2_NOTEMPTY_ATSTART,     PCRE2_NO_UTF_CHECK,     PCRE2_PARTIAL_HARD,
-       PCRE2_PARTIAL_SOFT, PCRE2_DFA_SHORTEST, and PCRE2_DFA_RESTART. All  but
-       the  last  four  of these are exactly the same as for pcre2_match(), so
+       PCRE2_PARTIAL_SOFT,  PCRE2_DFA_SHORTEST, and PCRE2_DFA_RESTART. All but
+       the last four of these are exactly the same as  for  pcre2_match(),  so
        their description is not repeated here.
 
          PCRE2_PARTIAL_HARD
          PCRE2_PARTIAL_SOFT
 
-       These have the same general effect as they do  for  pcre2_match(),  but
-       the  details are slightly different. When PCRE2_PARTIAL_HARD is set for
-       pcre2_dfa_match(), it returns PCRE2_ERROR_PARTIAL if  the  end  of  the
+       These  have  the  same general effect as they do for pcre2_match(), but
+       the details are slightly different. When PCRE2_PARTIAL_HARD is set  for
+       pcre2_dfa_match(),  it  returns  PCRE2_ERROR_PARTIAL  if the end of the
        subject is reached and there is still at least one matching possibility
        that requires additional characters. This happens even if some complete
-       matches  have  already  been found. When PCRE2_PARTIAL_SOFT is set, the
-       return code PCRE2_ERROR_NOMATCH is converted  into  PCRE2_ERROR_PARTIAL
-       if  the  end  of  the  subject  is reached, there have been no complete
+       matches have already been found. When PCRE2_PARTIAL_SOFT  is  set,  the
+       return  code  PCRE2_ERROR_NOMATCH is converted into PCRE2_ERROR_PARTIAL
+       if the end of the subject is  reached,  there  have  been  no  complete
        matches, but there is still at least one matching possibility. The por-
-       tion  of  the  string that was inspected when the longest partial match
+       tion of the string that was inspected when the  longest  partial  match
        was found is set as the first matching string in both cases. There is a
-       more  detailed  discussion  of partial and multi-segment matching, with
+       more detailed discussion of partial and  multi-segment  matching,  with
        examples, in the pcre2partial documentation.
 
          PCRE2_DFA_SHORTEST
 
-       Setting the PCRE2_DFA_SHORTEST option causes the matching algorithm  to
+       Setting  the PCRE2_DFA_SHORTEST option causes the matching algorithm to
        stop as soon as it has found one match. Because of the way the alterna-
-       tive algorithm works, this is necessarily the shortest  possible  match
+       tive  algorithm  works, this is necessarily the shortest possible match
        at the first possible matching point in the subject string.
 
          PCRE2_DFA_RESTART
 
-       When  pcre2_dfa_match() returns a partial match, it is possible to call
+       When pcre2_dfa_match() returns a partial match, it is possible to  call
        it again, with additional subject characters, and have it continue with
        the same match. The PCRE2_DFA_RESTART option requests this action; when
-       it is set, the workspace and wscount options must  reference  the  same
-       vector  as  before  because data about the match so far is left in them
+       it  is  set,  the workspace and wscount options must reference the same
+       vector as before because data about the match so far is  left  in  them
        after a partial match. There is more discussion of this facility in the
        pcre2partial documentation.
 
@@ -3152,8 +3159,8 @@ MATCHING A PATTERN: THE ALTERNATIVE FUNCTION
 
        When pcre2_dfa_match() succeeds, it may have matched more than one sub-
        string in the subject. Note, however, that all the matches from one run
-       of  the  function  start  at the same point in the subject. The shorter
-       matches are all initial substrings of the longer matches. For  example,
+       of the function start at the same point in  the  subject.  The  shorter
+       matches  are all initial substrings of the longer matches. For example,
        if the pattern
 
          <.*>
@@ -3168,17 +3175,17 @@ MATCHING A PATTERN: THE ALTERNATIVE FUNCTION
           
          
 
-       On  success,  the  yield of the function is a number greater than zero,
-       which is the number of matched substrings.  The  offsets  of  the  sub-
-       strings  are returned in the ovector, and can be extracted by number in
-       the same way as for pcre2_match(), but the numbers bear no relation  to
-       any  capturing groups that may exist in the pattern, because DFA match-
+       On success, the yield of the function is a number  greater  than  zero,
+       which  is  the  number  of  matched substrings. The offsets of the sub-
+       strings are returned in the ovector, and can be extracted by number  in
+       the  same way as for pcre2_match(), but the numbers bear no relation to
+       any capturing groups that may exist in the pattern, because DFA  match-
        ing does not support group capture.
 
-       Calls to the convenience functions  that  extract  substrings  by  name
-       return  the  error PCRE2_ERROR_DFA_UFUNC (unsupported function) if used
+       Calls  to  the  convenience  functions  that extract substrings by name
+       return the error PCRE2_ERROR_DFA_UFUNC (unsupported function)  if  used
        after a DFA match. The convenience functions that extract substrings by
-       number  never  return PCRE2_ERROR_NOSUBSTRING, and the meanings of some
+       number never return PCRE2_ERROR_NOSUBSTRING, and the meanings  of  some
        other errors are slightly different:
 
          PCRE2_ERROR_UNAVAILABLE
@@ -3188,64 +3195,64 @@ MATCHING A PATTERN: THE ALTERNATIVE FUNCTION
 
          PCRE2_ERROR_UNSET
 
-       There  is  a  slot  in  the  ovector for this substring, but there were
+       There is a slot in the ovector  for  this  substring,  but  there  were
        insufficient matches to fill it.
 
-       The matched strings are stored in  the  ovector  in  reverse  order  of
-       length;  that  is,  the longest matching string is first. If there were
-       too many matches to fit into the ovector, the yield of the function  is
+       The  matched  strings  are  stored  in  the ovector in reverse order of
+       length; that is, the longest matching string is first.  If  there  were
+       too  many matches to fit into the ovector, the yield of the function is
        zero, and the vector is filled with the longest matches.
 
-       NOTE:  PCRE2's  "auto-possessification" optimization usually applies to
-       character repeats at the end of a pattern (as well as internally).  For
-       example,  the pattern "a\d+" is compiled as if it were "a\d++". For DFA
-       matching, this means that only one possible  match  is  found.  If  you
-       really  do  want multiple matches in such cases, either use an ungreedy
-       repeat auch as "a\d+?" or set  the  PCRE2_NO_AUTO_POSSESS  option  when
+       NOTE: PCRE2's "auto-possessification" optimization usually  applies  to
+       character  repeats at the end of a pattern (as well as internally). For
+       example, the pattern "a\d+" is compiled as if it were "a\d++". For  DFA
+       matching,  this  means  that  only  one possible match is found. If you
+       really do want multiple matches in such cases, either use  an  ungreedy
+       repeat  auch  as  "a\d+?"  or set the PCRE2_NO_AUTO_POSSESS option when
        compiling.
 
    Error returns from pcre2_dfa_match()
 
        The pcre2_dfa_match() function returns a negative number when it fails.
-       Many of the errors are the same  as  for  pcre2_match(),  as  described
+       Many  of  the  errors  are  the same as for pcre2_match(), as described
        above.  There are in addition the following errors that are specific to
        pcre2_dfa_match():
 
          PCRE2_ERROR_DFA_UITEM
 
-       This return is given if pcre2_dfa_match() encounters  an  item  in  the
-       pattern  that it does not support, for instance, the use of \C in a UTF
+       This  return  is  given  if pcre2_dfa_match() encounters an item in the
+       pattern that it does not support, for instance, the use of \C in a  UTF
        mode or a back reference.
 
          PCRE2_ERROR_DFA_UCOND
 
-       This return is given if pcre2_dfa_match() encounters a  condition  item
-       that  uses  a back reference for the condition, or a test for recursion
+       This  return  is given if pcre2_dfa_match() encounters a condition item
+       that uses a back reference for the condition, or a test  for  recursion
        in a specific group. These are not supported.
 
          PCRE2_ERROR_DFA_WSSIZE
 
-       This return is given if pcre2_dfa_match() runs  out  of  space  in  the
+       This  return  is  given  if  pcre2_dfa_match() runs out of space in the
        workspace vector.
 
          PCRE2_ERROR_DFA_RECURSE
 
-       When  a  recursive subpattern is processed, the matching function calls
+       When a recursive subpattern is processed, the matching  function  calls
        itself recursively, using private memory for the ovector and workspace.
-       This  error  is given if the internal ovector is not large enough. This
+       This error is given if the internal ovector is not large  enough.  This
        should be extremely rare, as a vector of size 1000 is used.
 
          PCRE2_ERROR_DFA_BADRESTART
 
-       When pcre2_dfa_match() is called  with  the  PCRE2_DFA_RESTART  option,
-       some  plausibility  checks  are  made on the contents of the workspace,
-       which should contain data about the previous partial match. If  any  of
+       When  pcre2_dfa_match()  is  called  with the PCRE2_DFA_RESTART option,
+       some plausibility checks are made on the  contents  of  the  workspace,
+       which  should  contain data about the previous partial match. If any of
        these checks fail, this error is given.
 
 
 SEE ALSO
 
-       pcre2build(3),    pcre2callout(3),    pcre2demo(3),   pcre2matching(3),
+       pcre2build(3),   pcre2callout(3),    pcre2demo(3),    pcre2matching(3),
        pcre2partial(3), pcre2posix(3), pcre2sample(3), pcre2unicode(3).
 
 
@@ -3258,7 +3265,7 @@ AUTHOR
 
 REVISION
 
-       Last updated: 14 April 2017
+       Last updated: 17 April 2017
        Copyright (c) 1997-2017 University of Cambridge.
 ------------------------------------------------------------------------------
  
@@ -4363,19 +4370,16 @@ DIFFERENCES BETWEEN PCRE2 AND PERL
        at  the  start  of  a  pattern  that set overall options that cannot be
        changed within the pattern.
 
-       18. The following new Perl 5.26 constructs are  not  yet  supported  in
-       PCRE2:
-
-       (a)  The  Perl  /a modifier restricts /d numbers to pure ascii, the new
-       /aa modifier restricts /i case-insensitive matching to pure ascii also,
-       ignoring  unicode  rules.  This  separation  cannot be represented with
-       PCRE2_UTF.
+       18. The Perl /a modifier restricts /d numbers to pure  ascii,  and  the
+       /aa  modifier  restricts  /i  case-insensitive  matching to pure ascii,
+       ignoring Unicode rules. This  separation  cannot  be  represented  with
+       PCRE2_UCP.
 
        19. Perl has different limits than PCRE2. See the pcre2limit documenta-
        tion for details. Perl went with 5.10 from recursion to iteration keep-
        ing the intermediate matches on the heap, which is ~10% slower but does
-       not  fall into any stack-overflow limit. PCRE2 made a similar change at
-       release 10.30, and also has many build-time and  run-time  customizable
+       not fall into any stack-overflow limit. PCRE2 made a similar change  at
+       release  10.30,  and also has many build-time and run-time customizable
        limits.
 
 
@@ -4388,7 +4392,7 @@ AUTHOR
 
 REVISION
 
-       Last updated: 17 April 2017
+       Last updated: 18 April 2017
        Copyright (c) 1997-2017 University of Cambridge.
 ------------------------------------------------------------------------------
  
@@ -6798,51 +6802,55 @@ VERTICAL BAR
 
 INTERNAL OPTION SETTING
 
-       The  settings of the PCRE2_CASELESS, PCRE2_MULTILINE, PCRE2_DOTALL, and
-       PCRE2_EXTENDED options (which are Perl-compatible) can be changed  from
-       within  the  pattern  by  a  sequence  of  Perl option letters enclosed
-       between "(?" and ")".  The option letters are
+       The  settings  of  the  PCRE2_CASELESS,  PCRE2_MULTILINE, PCRE2_DOTALL,
+       PCRE2_EXTENDED, and PCRE2_EXTENDED_MORE options (which are Perl-compat-
+       ible)  can  be  changed  from  within the pattern by a sequence of Perl
+       option letters enclosed between "(?" and ")". The option letters are
 
          i  for PCRE2_CASELESS
          m  for PCRE2_MULTILINE
          s  for PCRE2_DOTALL
          x  for PCRE2_EXTENDED
+         xx for PCRE2_EXTENDED_MORE
 
        For example, (?im) sets caseless, multiline matching. It is also possi-
-       ble to unset these options by preceding the letter with a hyphen, and a
-       combined setting and unsetting such as (?im-sx), which sets PCRE2_CASE-
-       LESS    and    PCRE2_MULTILINE   while   unsetting   PCRE2_DOTALL   and
-       PCRE2_EXTENDED, is also permitted. If a letter appears both before  and
-       after  the  hyphen, the option is unset. An empty options setting "(?)"
+       ble  to  unset these options by preceding the letter with a hyphen. The
+       two "extended" options are not independent; unsetting either  one  can-
+       cels the effects of both of them.
+
+       A   combined  setting  and  unsetting  such  as  (?im-sx),  which  sets
+       PCRE2_CASELESS and PCRE2_MULTILINE  while  unsetting  PCRE2_DOTALL  and
+       PCRE2_EXTENDED,  is also permitted. If a letter appears both before and
+       after the hyphen, the option is unset. An empty options  setting  "(?)"
        is allowed. Needless to say, it has no effect.
 
-       The PCRE2-specific options PCRE2_DUPNAMES  and  PCRE2_UNGREEDY  can  be
-       changed  in  the  same  way as the Perl-compatible options by using the
+       The  PCRE2-specific  options  PCRE2_DUPNAMES  and PCRE2_UNGREEDY can be
+       changed in the same way as the Perl-compatible  options  by  using  the
        characters J and U respectively.
 
-       When one of these option changes occurs at  top  level  (that  is,  not
-       inside  subpattern parentheses), the change applies to the remainder of
-       the pattern that follows. An option change  within  a  subpattern  (see
-       below  for  a description of subpatterns) affects only that part of the
+       When  one  of  these  option  changes occurs at top level (that is, not
+       inside subpattern parentheses), the change applies to the remainder  of
+       the  pattern  that  follows.  An option change within a subpattern (see
+       below for a description of subpatterns) affects only that part  of  the
        subpattern that follows it, so
 
          (a(?i)b)c
 
-       matches abc and aBc and no other strings  (assuming  PCRE2_CASELESS  is
-       not  used).   By this means, options can be made to have different set-
+       matches  abc  and  aBc and no other strings (assuming PCRE2_CASELESS is
+       not used).  By this means, options can be made to have  different  set-
        tings in different parts of the pattern. Any changes made in one alter-
        native do carry on into subsequent branches within the same subpattern.
        For example,
 
          (a(?i)b|c)
 
-       matches "ab", "aB", "c", and "C", even though  when  matching  "C"  the
-       first  branch  is  abandoned before the option setting. This is because
-       the effects of option settings happen at compile time. There  would  be
+       matches  "ab",  "aB",  "c",  and "C", even though when matching "C" the
+       first branch is abandoned before the option setting.  This  is  because
+       the  effects  of option settings happen at compile time. There would be
        some very weird behaviour otherwise.
 
-       As  a  convenient shorthand, if any option settings are required at the
-       start of a non-capturing subpattern (see the next section), the  option
+       As a convenient shorthand, if any option settings are required  at  the
+       start  of a non-capturing subpattern (see the next section), the option
        letters may appear between the "?" and the ":". Thus the two patterns
 
          (?i:saturday|sunday)
@@ -6850,14 +6858,14 @@ INTERNAL OPTION SETTING
 
        match exactly the same set of strings.
 
-       Note:  There  are  other  PCRE2-specific options that can be set by the
+       Note: There are other PCRE2-specific options that can  be  set  by  the
        application when the compiling function is called. The pattern can con-
-       tain  special  leading  sequences  such as (*CRLF) to override what the
-       application has set or what has been defaulted. Details  are  given  in
-       the  section  entitled  "Newline  sequences"  above. There are also the
-       (*UTF) and (*UCP) leading sequences that can be used  to  set  UTF  and
-       Unicode  property  modes;  they are equivalent to setting the PCRE2_UTF
-       and PCRE2_UCP options, respectively. However, the application  can  set
+       tain special leading sequences such as (*CRLF)  to  override  what  the
+       application  has  set  or what has been defaulted. Details are given in
+       the section entitled "Newline sequences"  above.  There  are  also  the
+       (*UTF)  and  (*UCP)  leading  sequences that can be used to set UTF and
+       Unicode property modes; they are equivalent to  setting  the  PCRE2_UTF
+       and  PCRE2_UCP  options, respectively. However, the application can set
        the PCRE2_NEVER_UTF and PCRE2_NEVER_UCP options, which lock out the use
        of the (*UTF) and (*UCP) sequences.
 
@@ -6871,18 +6879,18 @@ SUBPATTERNS
 
          cat(aract|erpillar|)
 
-       matches  "cataract",  "caterpillar", or "cat". Without the parentheses,
+       matches "cataract", "caterpillar", or "cat". Without  the  parentheses,
        it would match "cataract", "erpillar" or an empty string.
 
-       2. It sets up the subpattern as  a  capturing  subpattern.  This  means
+       2.  It  sets  up  the  subpattern as a capturing subpattern. This means
        that, when the whole pattern matches, the portion of the subject string
-       that matched the subpattern is passed back to  the  caller,  separately
-       from  the portion that matched the whole pattern. (This applies only to
-       the traditional matching function; the DFA matching function  does  not
+       that  matched  the  subpattern is passed back to the caller, separately
+       from the portion that matched the whole pattern. (This applies only  to
+       the  traditional  matching function; the DFA matching function does not
        support capturing.)
 
        Opening parentheses are counted from left to right (starting from 1) to
-       obtain numbers for the  capturing  subpatterns.  For  example,  if  the
+       obtain  numbers  for  the  capturing  subpatterns.  For example, if the
        string "the red king" is matched against the pattern
 
          the ((red|white) (king|queen))
@@ -6890,12 +6898,12 @@ SUBPATTERNS
        the captured substrings are "red king", "red", and "king", and are num-
        bered 1, 2, and 3, respectively.
 
-       The fact that plain parentheses fulfil  two  functions  is  not  always
-       helpful.   There are often times when a grouping subpattern is required
-       without a capturing requirement. If an opening parenthesis is  followed
-       by  a question mark and a colon, the subpattern does not do any captur-
-       ing, and is not counted when computing the  number  of  any  subsequent
-       capturing  subpatterns. For example, if the string "the white queen" is
+       The  fact  that  plain  parentheses  fulfil two functions is not always
+       helpful.  There are often times when a grouping subpattern is  required
+       without  a capturing requirement. If an opening parenthesis is followed
+       by a question mark and a colon, the subpattern does not do any  captur-
+       ing,  and  is  not  counted when computing the number of any subsequent
+       capturing subpatterns. For example, if the string "the white queen"  is
        matched against the pattern
 
          the ((?:red|white) (king|queen))
@@ -6903,37 +6911,37 @@ SUBPATTERNS
        the captured substrings are "white queen" and "queen", and are numbered
        1 and 2. The maximum number of capturing subpatterns is 65535.
 
-       As  a  convenient shorthand, if any option settings are required at the
-       start of a non-capturing subpattern,  the  option  letters  may  appear
+       As a convenient shorthand, if any option settings are required  at  the
+       start  of  a  non-capturing  subpattern,  the option letters may appear
        between the "?" and the ":". Thus the two patterns
 
          (?i:saturday|sunday)
          (?:(?i)saturday|sunday)
 
        match exactly the same set of strings. Because alternative branches are
-       tried from left to right, and options are not reset until  the  end  of
-       the  subpattern is reached, an option setting in one branch does affect
-       subsequent branches, so the above patterns match "SUNDAY"  as  well  as
+       tried  from  left  to right, and options are not reset until the end of
+       the subpattern is reached, an option setting in one branch does  affect
+       subsequent  branches,  so  the above patterns match "SUNDAY" as well as
        "Saturday".
 
 
 DUPLICATE SUBPATTERN NUMBERS
 
        Perl 5.10 introduced a feature whereby each alternative in a subpattern
-       uses the same numbers for its capturing parentheses. Such a  subpattern
-       starts  with (?| and is itself a non-capturing subpattern. For example,
+       uses  the same numbers for its capturing parentheses. Such a subpattern
+       starts with (?| and is itself a non-capturing subpattern. For  example,
        consider this pattern:
 
          (?|(Sat)ur|(Sun))day
 
-       Because the two alternatives are inside a (?| group, both sets of  cap-
-       turing  parentheses  are  numbered one. Thus, when the pattern matches,
-       you can look at captured substring number  one,  whichever  alternative
-       matched.  This  construct  is useful when you want to capture part, but
+       Because  the two alternatives are inside a (?| group, both sets of cap-
+       turing parentheses are numbered one. Thus, when  the  pattern  matches,
+       you  can  look  at captured substring number one, whichever alternative
+       matched. This construct is useful when you want to  capture  part,  but
        not all, of one of a number of alternatives. Inside a (?| group, paren-
-       theses  are  numbered as usual, but the number is reset at the start of
-       each branch. The numbers of any capturing parentheses that  follow  the
-       subpattern  start after the highest number used in any branch. The fol-
+       theses are numbered as usual, but the number is reset at the  start  of
+       each  branch.  The numbers of any capturing parentheses that follow the
+       subpattern start after the highest number used in any branch. The  fol-
        lowing example is taken from the Perl documentation. The numbers under-
        neath show in which buffer the captured content will be stored.
 
@@ -6941,14 +6949,14 @@ DUPLICATE SUBPATTERN NUMBERS
          / ( a )  (?| x ( y ) z | (p (q) r) | (t) u (v) ) ( z ) /x
          # 1            2         2  3        2     3     4
 
-       A  back  reference  to a numbered subpattern uses the most recent value
-       that is set for that number by any subpattern.  The  following  pattern
+       A back reference to a numbered subpattern uses the  most  recent  value
+       that  is  set  for that number by any subpattern. The following pattern
        matches "abcabc" or "defdef":
 
          /(?|(abc)|(def))\1/
 
-       In  contrast,  a subroutine call to a numbered subpattern always refers
-       to the first one in the pattern with the given  number.  The  following
+       In contrast, a subroutine call to a numbered subpattern  always  refers
+       to  the  first  one in the pattern with the given number. The following
        pattern matches "abcabc" or "defabc":
 
          /(?|(abc)|(def))(?1)/
@@ -6956,47 +6964,47 @@ DUPLICATE SUBPATTERN NUMBERS
        A relative reference such as (?-1) is no different: it is just a conve-
        nient way of computing an absolute group number.
 
-       If a condition test for a subpattern's having matched refers to a  non-
-       unique  number, the test is true if any of the subpatterns of that num-
+       If  a condition test for a subpattern's having matched refers to a non-
+       unique number, the test is true if any of the subpatterns of that  num-
        ber have matched.
 
-       An alternative approach to using this "branch reset" feature is to  use
+       An  alternative approach to using this "branch reset" feature is to use
        duplicate named subpatterns, as described in the next section.
 
 
 NAMED SUBPATTERNS
 
-       Identifying  capturing  parentheses  by number is simple, but it can be
-       very hard to keep track of the numbers in complicated  regular  expres-
-       sions.  Furthermore,  if  an  expression  is  modified, the numbers may
+       Identifying capturing parentheses by number is simple, but  it  can  be
+       very  hard  to keep track of the numbers in complicated regular expres-
+       sions. Furthermore, if an  expression  is  modified,  the  numbers  may
        change. To help with this difficulty, PCRE2 supports the naming of sub-
        patterns. This feature was not added to Perl until release 5.10. Python
-       had the feature earlier, and PCRE1 introduced it at release 4.0,  using
-       the  Python syntax. PCRE2 supports both the Perl and the Python syntax.
-       Perl allows identically numbered subpatterns to have  different  names,
+       had  the feature earlier, and PCRE1 introduced it at release 4.0, using
+       the Python syntax. PCRE2 supports both the Perl and the Python  syntax.
+       Perl  allows  identically numbered subpatterns to have different names,
        but PCRE2 does not.
 
-       In  PCRE2, a subpattern can be named in one of three ways: (?...)
-       or (?'name'...) as in Perl, or (?P...) as in  Python.  References
-       to  capturing parentheses from other parts of the pattern, such as back
-       references, recursion, and conditions, can be made by name as  well  as
+       In PCRE2, a subpattern can be named in one of three ways:  (?...)
+       or  (?'name'...)  as in Perl, or (?P...) as in Python. References
+       to capturing parentheses from other parts of the pattern, such as  back
+       references,  recursion,  and conditions, can be made by name as well as
        by number.
 
-       Names  consist of up to 32 alphanumeric characters and underscores, but
-       must start with a non-digit.  Named  capturing  parentheses  are  still
-       allocated  numbers  as  well as names, exactly as if the names were not
+       Names consist of up to 32 alphanumeric characters and underscores,  but
+       must  start  with  a  non-digit.  Named capturing parentheses are still
+       allocated numbers as well as names, exactly as if the  names  were  not
        present. The PCRE2 API provides function calls for extracting the name-
-       to-number  translation  table  from  a compiled pattern. There are also
+       to-number translation table from a compiled  pattern.  There  are  also
        convenience functions for extracting a captured substring by name.
 
-       By default, a name must be unique within a pattern, but it is  possible
-       to  relax  this constraint by setting the PCRE2_DUPNAMES option at com-
-       pile time.  (Duplicate names are also always permitted for  subpatterns
-       with  the  same  number,  set up as described in the previous section.)
-       Duplicate names can be useful for patterns where only one  instance  of
+       By  default, a name must be unique within a pattern, but it is possible
+       to relax this constraint by setting the PCRE2_DUPNAMES option  at  com-
+       pile  time.  (Duplicate names are also always permitted for subpatterns
+       with the same number, set up as described  in  the  previous  section.)
+       Duplicate  names  can be useful for patterns where only one instance of
        the named parentheses can match.  Suppose you want to match the name of
-       a weekday, either as a 3-letter abbreviation or as the full  name,  and
-       in  both  cases  you  want  to  extract  the abbreviation. This pattern
+       a  weekday,  either as a 3-letter abbreviation or as the full name, and
+       in both cases you  want  to  extract  the  abbreviation.  This  pattern
        (ignoring the line breaks) does the job:
 
          (?Mon|Fri|Sun)(?:day)?|
@@ -7005,18 +7013,18 @@ NAMED SUBPATTERNS
          (?Thu)(?:rsday)?|
          (?Sat)(?:urday)?
 
-       There are five capturing substrings, but only one is ever set  after  a
+       There  are  five capturing substrings, but only one is ever set after a
        match.  (An alternative way of solving this problem is to use a "branch
        reset" subpattern, as described in the previous section.)
 
-       The convenience functions for extracting the data by name  returns  the
-       substring  for  the first (and in this example, the only) subpattern of
-       that name that matched. This saves searching  to  find  which  numbered
+       The  convenience  functions for extracting the data by name returns the
+       substring for the first (and in this example, the only)  subpattern  of
+       that  name  that  matched.  This saves searching to find which numbered
        subpattern it was.
 
-       If  you  make  a  back  reference to a non-unique named subpattern from
-       elsewhere in the pattern, the subpatterns to which the name refers  are
-       checked  in  the order in which they appear in the overall pattern. The
+       If you make a back reference to  a  non-unique  named  subpattern  from
+       elsewhere  in the pattern, the subpatterns to which the name refers are
+       checked in the order in which they appear in the overall  pattern.  The
        first one that is set is used for the reference. For example, this pat-
        tern matches both "foofoo" and "barbar" but not "foobar" or "barfoo":
 
@@ -7024,29 +7032,29 @@ NAMED SUBPATTERNS
 
 
        If you make a subroutine call to a non-unique named subpattern, the one
-       that corresponds to the first occurrence of the name is  used.  In  the
+       that  corresponds  to  the first occurrence of the name is used. In the
        absence of duplicate numbers (see the previous section) this is the one
        with the lowest number.
 
        If you use a named reference in a condition test (see the section about
        conditions below), either to check whether a subpattern has matched, or
-       to check for recursion, all subpatterns with the same name are  tested.
-       If  the condition is true for any one of them, the overall condition is
-       true. This is the same behaviour as  testing  by  number.  For  further
-       details  of  the  interfaces  for  handling  named subpatterns, see the
+       to  check for recursion, all subpatterns with the same name are tested.
+       If the condition is true for any one of them, the overall condition  is
+       true.  This  is  the  same  behaviour as testing by number. For further
+       details of the interfaces  for  handling  named  subpatterns,  see  the
        pcre2api documentation.
 
        Warning: You cannot use different names to distinguish between two sub-
-       patterns  with the same number because PCRE2 uses only the numbers when
+       patterns with the same number because PCRE2 uses only the numbers  when
        matching. For this reason, an error is given at compile time if differ-
-       ent  names  are given to subpatterns with the same number. However, you
+       ent names are given to subpatterns with the same number.  However,  you
        can always give the same name to subpatterns with the same number, even
        when PCRE2_DUPNAMES is not set.
 
 
 REPETITION
 
-       Repetition  is  specified  by  quantifiers, which can follow any of the
+       Repetition is specified by quantifiers, which can  follow  any  of  the
        following items:
 
          a literal data character
@@ -7060,17 +7068,17 @@ REPETITION
          a parenthesized subpattern (including most assertions)
          a subroutine call to a subpattern (recursive or otherwise)
 
-       The general repetition quantifier specifies a minimum and maximum  num-
-       ber  of  permitted matches, by giving the two numbers in curly brackets
-       (braces), separated by a comma. The numbers must be  less  than  65536,
+       The  general repetition quantifier specifies a minimum and maximum num-
+       ber of permitted matches, by giving the two numbers in  curly  brackets
+       (braces),  separated  by  a comma. The numbers must be less than 65536,
        and the first must be less than or equal to the second. For example:
 
          z{2,4}
 
-       matches  "zz",  "zzz",  or  "zzzz". A closing brace on its own is not a
-       special character. If the second number is omitted, but  the  comma  is
-       present,  there  is  no upper limit; if the second number and the comma
-       are both omitted, the quantifier specifies an exact number of  required
+       matches "zz", "zzz", or "zzzz". A closing brace on its  own  is  not  a
+       special  character.  If  the second number is omitted, but the comma is
+       present, there is no upper limit; if the second number  and  the  comma
+       are  both omitted, the quantifier specifies an exact number of required
        matches. Thus
 
          [aeiou]{3,}
@@ -7079,50 +7087,50 @@ REPETITION
 
          \d{8}
 
-       matches  exactly  8  digits. An opening curly bracket that appears in a
-       position where a quantifier is not allowed, or one that does not  match
-       the  syntax of a quantifier, is taken as a literal character. For exam-
+       matches exactly 8 digits. An opening curly bracket that  appears  in  a
+       position  where a quantifier is not allowed, or one that does not match
+       the syntax of a quantifier, is taken as a literal character. For  exam-
        ple, {,6} is not a quantifier, but a literal string of four characters.
 
        In UTF modes, quantifiers apply to characters rather than to individual
-       code  units. Thus, for example, \x{100}{2} matches two characters, each
+       code units. Thus, for example, \x{100}{2} matches two characters,  each
        of which is represented by a two-byte sequence in a UTF-8 string. Simi-
-       larly,  \X{3} matches three Unicode extended grapheme clusters, each of
-       which may be several code units long (and  they  may  be  of  different
+       larly, \X{3} matches three Unicode extended grapheme clusters, each  of
+       which  may  be  several  code  units long (and they may be of different
        lengths).
 
        The quantifier {0} is permitted, causing the expression to behave as if
        the previous item and the quantifier were not present. This may be use-
-       ful  for  subpatterns that are referenced as subroutines from elsewhere
+       ful for subpatterns that are referenced as subroutines  from  elsewhere
        in the pattern (but see also the section entitled "Defining subpatterns
-       for  use  by  reference only" below). Items other than subpatterns that
+       for use by reference only" below). Items other  than  subpatterns  that
        have a {0} quantifier are omitted from the compiled pattern.
 
-       For convenience, the three most common quantifiers have  single-charac-
+       For  convenience, the three most common quantifiers have single-charac-
        ter abbreviations:
 
          *    is equivalent to {0,}
          +    is equivalent to {1,}
          ?    is equivalent to {0,1}
 
-       It  is  possible  to construct infinite loops by following a subpattern
+       It is possible to construct infinite loops by  following  a  subpattern
        that can match no characters with a quantifier that has no upper limit,
        for example:
 
          (a?)*
 
-       Earlier  versions  of  Perl  and PCRE1 used to give an error at compile
+       Earlier versions of Perl and PCRE1 used to give  an  error  at  compile
        time for such patterns. However, because there are cases where this can
        be useful, such patterns are now accepted, but if any repetition of the
-       subpattern does in fact match no characters, the loop is forcibly  bro-
+       subpattern  does in fact match no characters, the loop is forcibly bro-
        ken.
 
-       By  default,  the quantifiers are "greedy", that is, they match as much
-       as possible (up to the maximum  number  of  permitted  times),  without
-       causing  the  rest of the pattern to fail. The classic example of where
+       By default, the quantifiers are "greedy", that is, they match  as  much
+       as  possible  (up  to  the  maximum number of permitted times), without
+       causing the rest of the pattern to fail. The classic example  of  where
        this gives problems is in trying to match comments in C programs. These
-       appear  between  /*  and  */ and within the comment, individual * and /
-       characters may appear. An attempt to match C comments by  applying  the
+       appear between /* and */ and within the comment,  individual  *  and  /
+       characters  may  appear. An attempt to match C comments by applying the
        pattern
 
          /\*.*\*/
@@ -7131,19 +7139,19 @@ REPETITION
 
          /* first comment */  not comment  /* second comment */
 
-       fails,  because it matches the entire string owing to the greediness of
+       fails, because it matches the entire string owing to the greediness  of
        the .*  item.
 
        If a quantifier is followed by a question mark, it ceases to be greedy,
-       and  instead  matches the minimum number of times possible, so the pat-
+       and instead matches the minimum number of times possible, so  the  pat-
        tern
 
          /\*.*?\*/
 
-       does the right thing with the C comments. The meaning  of  the  various
-       quantifiers  is  not  otherwise  changed,  just the preferred number of
-       matches.  Do not confuse this use of question mark with its  use  as  a
-       quantifier  in its own right. Because it has two uses, it can sometimes
+       does  the  right  thing with the C comments. The meaning of the various
+       quantifiers is not otherwise changed,  just  the  preferred  number  of
+       matches.   Do  not  confuse this use of question mark with its use as a
+       quantifier in its own right. Because it has two uses, it can  sometimes
        appear doubled, as in
 
          \d??\d
@@ -7152,45 +7160,45 @@ REPETITION
        only way the rest of the pattern matches.
 
        If the PCRE2_UNGREEDY option is set (an option that is not available in
-       Perl), the quantifiers are not greedy by default, but  individual  ones
-       can  be  made  greedy  by following them with a question mark. In other
+       Perl),  the  quantifiers are not greedy by default, but individual ones
+       can be made greedy by following them with a  question  mark.  In  other
        words, it inverts the default behaviour.
 
-       When a parenthesized subpattern is quantified  with  a  minimum  repeat
-       count  that is greater than 1 or with a limited maximum, more memory is
-       required for the compiled pattern, in proportion to  the  size  of  the
+       When  a  parenthesized  subpattern  is quantified with a minimum repeat
+       count that is greater than 1 or with a limited maximum, more memory  is
+       required  for  the  compiled  pattern, in proportion to the size of the
        minimum or maximum.
 
-       If  a  pattern  starts  with  .*  or  .{0,} and the PCRE2_DOTALL option
-       (equivalent to Perl's /s) is set, thus allowing the dot to  match  new-
-       lines,  the  pattern  is  implicitly anchored, because whatever follows
-       will be tried against every character position in the  subject  string,
-       so  there  is  no  point  in retrying the overall match at any position
+       If a pattern starts with  .*  or  .{0,}  and  the  PCRE2_DOTALL  option
+       (equivalent  to  Perl's /s) is set, thus allowing the dot to match new-
+       lines, the pattern is implicitly  anchored,  because  whatever  follows
+       will  be  tried against every character position in the subject string,
+       so there is no point in retrying the  overall  match  at  any  position
        after the first. PCRE2 normally treats such a pattern as though it were
        preceded by \A.
 
-       In  cases  where  it  is known that the subject string contains no new-
-       lines, it is worth setting PCRE2_DOTALL in order to obtain  this  opti-
+       In cases where it is known that the subject  string  contains  no  new-
+       lines,  it  is worth setting PCRE2_DOTALL in order to obtain this opti-
        mization, or alternatively, using ^ to indicate anchoring explicitly.
 
-       However,  there  are  some cases where the optimization cannot be used.
+       However, there are some cases where the optimization  cannot  be  used.
        When .*  is inside capturing parentheses that are the subject of a back
        reference elsewhere in the pattern, a match at the start may fail where
        a later one succeeds. Consider, for example:
 
          (.*)abc\1
 
-       If the subject is "xyz123abc123" the match point is the fourth  charac-
+       If  the subject is "xyz123abc123" the match point is the fourth charac-
        ter. For this reason, such a pattern is not implicitly anchored.
 
-       Another  case where implicit anchoring is not applied is when the lead-
-       ing .* is inside an atomic group. Once again, a match at the start  may
+       Another case where implicit anchoring is not applied is when the  lead-
+       ing  .* is inside an atomic group. Once again, a match at the start may
        fail where a later one succeeds. Consider this pattern:
 
          (?>.*?a)b
 
-       It  matches "ab" in the subject "aab". The use of the backtracking con-
-       trol verbs (*PRUNE) and (*SKIP) also  disable  this  optimization,  and
+       It matches "ab" in the subject "aab". The use of the backtracking  con-
+       trol  verbs  (*PRUNE)  and  (*SKIP) also disable this optimization, and
        there is an option, PCRE2_NO_DOTSTAR_ANCHOR, to do so explicitly.
 
        When a capturing subpattern is repeated, the value captured is the sub-
@@ -7199,8 +7207,8 @@ REPETITION
          (tweedle[dume]{3}\s*)+
 
        has matched "tweedledum tweedledee" the value of the captured substring
-       is  "tweedledee".  However,  if there are nested capturing subpatterns,
-       the corresponding captured values may have been set in previous  itera-
+       is "tweedledee". However, if there are  nested  capturing  subpatterns,
+       the  corresponding captured values may have been set in previous itera-
        tions. For example, after
 
          (a|(b))+
@@ -7210,53 +7218,53 @@ REPETITION
 
 ATOMIC GROUPING AND POSSESSIVE QUANTIFIERS
 
-       With  both  maximizing ("greedy") and minimizing ("ungreedy" or "lazy")
-       repetition, failure of what follows normally causes the  repeated  item
-       to  be  re-evaluated to see if a different number of repeats allows the
-       rest of the pattern to match. Sometimes it is useful to  prevent  this,
-       either  to  change the nature of the match, or to cause it fail earlier
-       than it otherwise might, when the author of the pattern knows there  is
+       With both maximizing ("greedy") and minimizing ("ungreedy"  or  "lazy")
+       repetition,  failure  of what follows normally causes the repeated item
+       to be re-evaluated to see if a different number of repeats  allows  the
+       rest  of  the pattern to match. Sometimes it is useful to prevent this,
+       either to change the nature of the match, or to cause it  fail  earlier
+       than  it otherwise might, when the author of the pattern knows there is
        no point in carrying on.
 
-       Consider,  for  example, the pattern \d+foo when applied to the subject
+       Consider, for example, the pattern \d+foo when applied to  the  subject
        line
 
          123456bar
 
        After matching all 6 digits and then failing to match "foo", the normal
-       action  of  the matcher is to try again with only 5 digits matching the
-       \d+ item, and then with  4,  and  so  on,  before  ultimately  failing.
-       "Atomic  grouping"  (a  term taken from Jeffrey Friedl's book) provides
-       the means for specifying that once a subpattern has matched, it is  not
+       action of the matcher is to try again with only 5 digits  matching  the
+       \d+  item,  and  then  with  4,  and  so on, before ultimately failing.
+       "Atomic grouping" (a term taken from Jeffrey  Friedl's  book)  provides
+       the  means for specifying that once a subpattern has matched, it is not
        to be re-evaluated in this way.
 
-       If  we  use atomic grouping for the previous example, the matcher gives
-       up immediately on failing to match "foo" the first time.  The  notation
+       If we use atomic grouping for the previous example, the  matcher  gives
+       up  immediately  on failing to match "foo" the first time. The notation
        is a kind of special parenthesis, starting with (?> as in this example:
 
          (?>\d+)foo
 
-       This  kind  of  parenthesis "locks up" the  part of the pattern it con-
-       tains once it has matched, and a failure further into  the  pattern  is
-       prevented  from  backtracking into it. Backtracking past it to previous
+       This kind of parenthesis "locks up" the  part of the  pattern  it  con-
+       tains  once  it  has matched, and a failure further into the pattern is
+       prevented from backtracking into it. Backtracking past it  to  previous
        items, however, works as normal.
 
-       An alternative description is that a subpattern of  this  type  matches
-       exactly  the  string of characters that an identical standalone pattern
+       An  alternative  description  is that a subpattern of this type matches
+       exactly the string of characters that an identical  standalone  pattern
        would match, if anchored at the current point in the subject string.
 
        Atomic grouping subpatterns are not capturing subpatterns. Simple cases
        such as the above example can be thought of as a maximizing repeat that
-       must swallow everything it can. So, while both \d+ and  \d+?  are  pre-
-       pared  to  adjust  the number of digits they match in order to make the
+       must  swallow  everything  it can. So, while both \d+ and \d+? are pre-
+       pared to adjust the number of digits they match in order  to  make  the
        rest of the pattern match, (?>\d+) can only match an entire sequence of
        digits.
 
-       Atomic  groups in general can of course contain arbitrarily complicated
-       subpatterns, and can be nested. However, when  the  subpattern  for  an
+       Atomic groups in general can of course contain arbitrarily  complicated
+       subpatterns,  and  can  be  nested. However, when the subpattern for an
        atomic group is just a single repeated item, as in the example above, a
-       simpler notation, called a "possessive quantifier" can  be  used.  This
-       consists  of  an  additional  + character following a quantifier. Using
+       simpler  notation,  called  a "possessive quantifier" can be used. This
+       consists of an additional + character  following  a  quantifier.  Using
        this notation, the previous example can be rewritten as
 
          \d++foo
@@ -7266,46 +7274,46 @@ ATOMIC GROUPING AND POSSESSIVE QUANTIFIERS
 
          (abc|xyz){2,3}+
 
-       Possessive   quantifiers   are   always  greedy;  the  setting  of  the
-       PCRE2_UNGREEDY option is ignored. They are a  convenient  notation  for
-       the  simpler  forms of atomic group. However, there is no difference in
+       Possessive  quantifiers  are  always  greedy;  the   setting   of   the
+       PCRE2_UNGREEDY  option  is  ignored. They are a convenient notation for
+       the simpler forms of atomic group. However, there is no  difference  in
        the meaning of a possessive quantifier and the equivalent atomic group,
-       though  there  may  be a performance difference; possessive quantifiers
+       though there may be a performance  difference;  possessive  quantifiers
        should be slightly faster.
 
-       The possessive quantifier syntax is an extension to the Perl  5.8  syn-
-       tax.   Jeffrey  Friedl  originated the idea (and the name) in the first
+       The  possessive  quantifier syntax is an extension to the Perl 5.8 syn-
+       tax.  Jeffrey Friedl originated the idea (and the name)  in  the  first
        edition of his book. Mike McCloskey liked it, so implemented it when he
        built Sun's Java package, and PCRE1 copied it from there. It ultimately
        found its way into Perl at release 5.10.
 
-       PCRE2 has an optimization  that  automatically  "possessifies"  certain
-       simple  pattern constructs. For example, the sequence A+B is treated as
-       A++B because there is no point in backtracking into a sequence  of  A's
+       PCRE2  has  an  optimization  that automatically "possessifies" certain
+       simple pattern constructs. For example, the sequence A+B is treated  as
+       A++B  because  there is no point in backtracking into a sequence of A's
        when B must follow.  This feature can be disabled by the PCRE2_NO_AUTO-
        POSSESS option, or starting the pattern with (*NO_AUTO_POSSESS).
 
-       When a pattern contains an unlimited repeat inside  a  subpattern  that
-       can  itself  be  repeated  an  unlimited number of times, the use of an
-       atomic group is the only way to avoid some  failing  matches  taking  a
+       When  a  pattern  contains an unlimited repeat inside a subpattern that
+       can itself be repeated an unlimited number of  times,  the  use  of  an
+       atomic  group  is  the  only way to avoid some failing matches taking a
        very long time indeed. The pattern
 
          (\D+|<\d+>)*[!?]
 
-       matches  an  unlimited number of substrings that either consist of non-
-       digits, or digits enclosed in <>, followed by either ! or  ?.  When  it
+       matches an unlimited number of substrings that either consist  of  non-
+       digits,  or  digits  enclosed in <>, followed by either ! or ?. When it
        matches, it runs quickly. However, if it is applied to
 
          aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
 
-       it  takes  a  long  time  before reporting failure. This is because the
-       string can be divided between the internal \D+ repeat and the  external
-       *  repeat  in  a  large  number of ways, and all have to be tried. (The
-       example uses [!?] rather than a single character at  the  end,  because
-       both  PCRE2  and Perl have an optimization that allows for fast failure
-       when a single character is used. They remember the last single  charac-
-       ter  that  is required for a match, and fail early if it is not present
-       in the string.) If the pattern is changed so that  it  uses  an  atomic
+       it takes a long time before reporting  failure.  This  is  because  the
+       string  can be divided between the internal \D+ repeat and the external
+       * repeat in a large number of ways, and all  have  to  be  tried.  (The
+       example  uses  [!?]  rather than a single character at the end, because
+       both PCRE2 and Perl have an optimization that allows for  fast  failure
+       when  a single character is used. They remember the last single charac-
+       ter that is required for a match, and fail early if it is  not  present
+       in  the  string.)  If  the pattern is changed so that it uses an atomic
        group, like this:
 
          ((?>\D+)|<\d+>)*[!?]
@@ -7317,28 +7325,28 @@ BACK REFERENCES
 
        Outside a character class, a backslash followed by a digit greater than
        0 (and possibly further digits) is a back reference to a capturing sub-
-       pattern  earlier  (that is, to its left) in the pattern, provided there
+       pattern earlier (that is, to its left) in the pattern,  provided  there
        have been that many previous capturing left parentheses.
 
-       However, if the decimal number following the backslash is less than  8,
-       it  is  always  taken  as a back reference, and causes an error only if
-       there are not that many capturing left parentheses in the  entire  pat-
-       tern.  In  other words, the parentheses that are referenced need not be
-       to the left of the reference for numbers less than 8. A  "forward  back
-       reference"  of  this  type can make sense when a repetition is involved
-       and the subpattern to the right has participated in an  earlier  itera-
+       However,  if the decimal number following the backslash is less than 8,
+       it is always taken as a back reference, and causes  an  error  only  if
+       there  are  not that many capturing left parentheses in the entire pat-
+       tern. In other words, the parentheses that are referenced need  not  be
+       to  the  left of the reference for numbers less than 8. A "forward back
+       reference" of this type can make sense when a  repetition  is  involved
+       and  the  subpattern to the right has participated in an earlier itera-
        tion.
 
-       It  is  not  possible to have a numerical "forward back reference" to a
-       subpattern whose number is 8  or  more  using  this  syntax  because  a
-       sequence  such  as  \50 is interpreted as a character defined in octal.
+       It is not possible to have a numerical "forward back  reference"  to  a
+       subpattern  whose  number  is  8  or  more  using this syntax because a
+       sequence such as \50 is interpreted as a character  defined  in  octal.
        See the subsection entitled "Non-printing characters" above for further
-       details  of  the  handling of digits following a backslash. There is no
-       such problem when named parentheses are used. A back reference  to  any
+       details of the handling of digits following a backslash.  There  is  no
+       such  problem  when named parentheses are used. A back reference to any
        subpattern is possible using named parentheses (see below).
 
-       Another  way  of  avoiding  the ambiguity inherent in the use of digits
-       following a backslash is to use the \g  escape  sequence.  This  escape
+       Another way of avoiding the ambiguity inherent in  the  use  of  digits
+       following  a  backslash  is  to use the \g escape sequence. This escape
        must be followed by a signed or unsigned number, optionally enclosed in
        braces. These examples are all identical:
 
@@ -7346,46 +7354,46 @@ BACK REFERENCES
          (ring), \g1
          (ring), \g{1}
 
-       An unsigned number specifies an absolute reference without the  ambigu-
+       An  unsigned number specifies an absolute reference without the ambigu-
        ity that is present in the older syntax. It is also useful when literal
-       digits follow the reference. A signed number is a  relative  reference.
+       digits  follow  the reference. A signed number is a relative reference.
        Consider this example:
 
          (abc(def)ghi)\g{-1}
 
        The sequence \g{-1} is a reference to the most recently started captur-
        ing subpattern before \g, that is, is it equivalent to \2 in this exam-
-       ple.   Similarly, \g{-2} would be equivalent to \1. The use of relative
-       references can be helpful in long patterns, and also in  patterns  that
-       are  created  by  joining  together  fragments  that contain references
+       ple.  Similarly, \g{-2} would be equivalent to \1. The use of  relative
+       references  can  be helpful in long patterns, and also in patterns that
+       are created by  joining  together  fragments  that  contain  references
        within themselves.
 
-       The sequence \g{+1} is a reference to the  next  capturing  subpattern.
-       This  kind  of forward reference can be useful it patterns that repeat.
+       The  sequence  \g{+1}  is a reference to the next capturing subpattern.
+       This kind of forward reference can be useful it patterns  that  repeat.
        Perl does not support the use of + in this way.
 
-       A back reference matches whatever actually matched the  capturing  sub-
-       pattern  in  the  current subject string, rather than anything matching
+       A  back  reference matches whatever actually matched the capturing sub-
+       pattern in the current subject string, rather  than  anything  matching
        the subpattern itself (see "Subpatterns as subroutines" below for a way
        of doing that). So the pattern
 
          (sens|respons)e and \1ibility
 
-       matches  "sense and sensibility" and "response and responsibility", but
-       not "sense and responsibility". If caseful matching is in force at  the
-       time  of the back reference, the case of letters is relevant. For exam-
+       matches "sense and sensibility" and "response and responsibility",  but
+       not  "sense and responsibility". If caseful matching is in force at the
+       time of the back reference, the case of letters is relevant. For  exam-
        ple,
 
          ((?i)rah)\s+\1
 
-       matches "rah rah" and "RAH RAH", but not "RAH  rah",  even  though  the
+       matches  "rah  rah"  and  "RAH RAH", but not "RAH rah", even though the
        original capturing subpattern is matched caselessly.
 
-       There  are  several  different ways of writing back references to named
-       subpatterns. The .NET syntax \k{name} and the Perl syntax  \k  or
-       \k'name'  are supported, as is the Python syntax (?P=name). Perl 5.10's
+       There are several different ways of writing back  references  to  named
+       subpatterns.  The  .NET syntax \k{name} and the Perl syntax \k or
+       \k'name' are supported, as is the Python syntax (?P=name). Perl  5.10's
        unified back reference syntax, in which \g can be used for both numeric
-       and  named  references,  is  also supported. We could rewrite the above
+       and named references, is also supported. We  could  rewrite  the  above
        example in any of the following ways:
 
          (?(?i)rah)\s+\k
@@ -7393,96 +7401,96 @@ BACK REFERENCES
          (?P(?i)rah)\s+(?P=p1)
          (?(?i)rah)\s+\g{p1}
 
-       A subpattern that is referenced by  name  may  appear  in  the  pattern
+       A  subpattern  that  is  referenced  by  name may appear in the pattern
        before or after the reference.
 
-       There  may be more than one back reference to the same subpattern. If a
-       subpattern has not actually been used in a particular match,  any  back
+       There may be more than one back reference to the same subpattern. If  a
+       subpattern  has  not actually been used in a particular match, any back
        references to it always fail by default. For example, the pattern
 
          (a|(bc))\2
 
-       always  fails  if  it starts to match "a" rather than "bc". However, if
-       the PCRE2_MATCH_UNSET_BACKREF option is set at  compile  time,  a  back
+       always fails if it starts to match "a" rather than  "bc".  However,  if
+       the  PCRE2_MATCH_UNSET_BACKREF  option  is  set at compile time, a back
        reference to an unset value matches an empty string.
 
-       Because  there may be many capturing parentheses in a pattern, all dig-
-       its following a backslash are taken as part of a potential back  refer-
-       ence  number.   If  the  pattern continues with a digit character, some
-       delimiter must  be  used  to  terminate  the  back  reference.  If  the
-       PCRE2_EXTENDED  option  is set, this can be white space. Otherwise, the
+       Because there may be many capturing parentheses in a pattern, all  dig-
+       its  following a backslash are taken as part of a potential back refer-
+       ence number.  If the pattern continues with  a  digit  character,  some
+       delimiter  must  be  used  to  terminate  the  back  reference.  If the
+       PCRE2_EXTENDED option is set, this can be white space.  Otherwise,  the
        \g{ syntax or an empty comment (see "Comments" below) can be used.
 
    Recursive back references
 
-       A back reference that occurs inside the parentheses to which it  refers
-       fails  when  the subpattern is first used, so, for example, (a\1) never
-       matches.  However, such references can be useful inside  repeated  sub-
+       A  back reference that occurs inside the parentheses to which it refers
+       fails when the subpattern is first used, so, for example,  (a\1)  never
+       matches.   However,  such references can be useful inside repeated sub-
        patterns. For example, the pattern
 
          (a|b\1)+
 
        matches any number of "a"s and also "aba", "ababbaa" etc. At each iter-
-       ation of the subpattern,  the  back  reference  matches  the  character
-       string  corresponding  to  the previous iteration. In order for this to
-       work, the pattern must be such that the first iteration does  not  need
-       to  match the back reference. This can be done using alternation, as in
+       ation  of  the  subpattern,  the  back  reference matches the character
+       string corresponding to the previous iteration. In order  for  this  to
+       work,  the  pattern must be such that the first iteration does not need
+       to match the back reference. This can be done using alternation, as  in
        the example above, or by a quantifier with a minimum of zero.
 
-       Back references of this type cause the group that they reference to  be
-       treated  as  an atomic group.  Once the whole group has been matched, a
-       subsequent matching failure cannot cause backtracking into  the  middle
+       Back  references of this type cause the group that they reference to be
+       treated as an atomic group.  Once the whole group has been  matched,  a
+       subsequent  matching  failure cannot cause backtracking into the middle
        of the group.
 
 
 ASSERTIONS
 
-       An  assertion  is  a  test on the characters following or preceding the
+       An assertion is a test on the characters  following  or  preceding  the
        current matching point that does not consume any characters. The simple
-       assertions  coded  as  \b,  \B,  \A,  \G, \Z, \z, ^ and $ are described
+       assertions coded as \b, \B, \A, \G, \Z,  \z,  ^  and  $  are  described
        above.
 
-       More complicated assertions are coded as  subpatterns.  There  are  two
-       kinds:  those  that  look  ahead of the current position in the subject
-       string, and those that look behind it, and in each  case  an  assertion
-       may  be  positive  (must  succeed for matching to continue) or negative
+       More  complicated  assertions  are  coded as subpatterns. There are two
+       kinds: those that look ahead of the current  position  in  the  subject
+       string,  and  those  that look behind it, and in each case an assertion
+       may be positive (must succeed for matching  to  continue)  or  negative
        (must not succeed for matching to continue). An assertion subpattern is
-       matched  in the normal way, except that, when matching continues after-
-       wards, the matching position in the subject string is as it was at  the
+       matched in the normal way, except that, when matching continues  after-
+       wards,  the matching position in the subject string is as it was at the
        start of the assertion.
 
-       Assertion  subpatterns  are  not capturing subpatterns. If an assertion
-       contains capturing subpatterns within it, these  are  counted  for  the
-       purposes  of  numbering the capturing subpatterns in the whole pattern.
-       However, substring capturing is carried out only  for  positive  asser-
+       Assertion subpatterns are not capturing subpatterns.  If  an  assertion
+       contains  capturing  subpatterns  within  it, these are counted for the
+       purposes of numbering the capturing subpatterns in the  whole  pattern.
+       However,  substring  capturing  is carried out only for positive asser-
        tions that succeed, that is, one of their branches matches, so matching
-       continues after the assertion. If all branches of a positive  assertion
+       continues  after the assertion. If all branches of a positive assertion
        fail to match, nothing is captured, and control is passed to the previ-
        ous backtracking point.
 
-       No capturing is done for a negative assertion unless it is  being  used
-       as  a condition in a conditional subpattern (see the discussion below).
-       Matching continues after a non-conditional negative assertion  only  if
+       No  capturing  is done for a negative assertion unless it is being used
+       as a condition in a conditional subpattern (see the discussion  below).
+       Matching  continues  after a non-conditional negative assertion only if
        all its branches fail to match.
 
-       For   compatibility  with  Perl,  most  assertion  subpatterns  may  be
-       repeated; though it makes no sense to assert  the  same  thing  several
-       times,  the  side  effect  of capturing parentheses may occasionally be
-       useful. However, an assertion that forms the  condition  for  a  condi-
-       tional  subpattern may not be quantified. In practice, for other asser-
+       For  compatibility  with  Perl,  most  assertion  subpatterns  may   be
+       repeated;  though  it  makes  no sense to assert the same thing several
+       times, the side effect of capturing  parentheses  may  occasionally  be
+       useful.  However,  an  assertion  that forms the condition for a condi-
+       tional subpattern may not be quantified. In practice, for other  asser-
        tions, there only three cases:
 
-       (1) If the quantifier is {0}, the  assertion  is  never  obeyed  during
-       matching.   However,  it  may  contain internal capturing parenthesized
+       (1)  If  the  quantifier  is  {0}, the assertion is never obeyed during
+       matching.  However, it may  contain  internal  capturing  parenthesized
        groups that are called from elsewhere via the subroutine mechanism.
 
-       (2) If quantifier is {0,n} where n is greater than zero, it is  treated
-       as  if  it  were  {0,1}.  At run time, the rest of the pattern match is
+       (2)  If quantifier is {0,n} where n is greater than zero, it is treated
+       as if it were {0,1}. At run time, the rest  of  the  pattern  match  is
        tried with and without the assertion, the order depending on the greed-
        iness of the quantifier.
 
-       (3)  If  the minimum repetition is greater than zero, the quantifier is
-       ignored.  The assertion is obeyed just  once  when  encountered  during
+       (3) If the minimum repetition is greater than zero, the  quantifier  is
+       ignored.   The  assertion  is  obeyed just once when encountered during
        matching.
 
    Lookahead assertions
@@ -7492,38 +7500,38 @@ ASSERTIONS
 
          \w+(?=;)
 
-       matches a word followed by a semicolon, but does not include the  semi-
+       matches  a word followed by a semicolon, but does not include the semi-
        colon in the match, and
 
          foo(?!bar)
 
-       matches  any  occurrence  of  "foo" that is not followed by "bar". Note
+       matches any occurrence of "foo" that is not  followed  by  "bar".  Note
        that the apparently similar pattern
 
          (?!foo)bar
 
-       does not find an occurrence of "bar"  that  is  preceded  by  something
-       other  than "foo"; it finds any occurrence of "bar" whatsoever, because
+       does  not  find  an  occurrence  of "bar" that is preceded by something
+       other than "foo"; it finds any occurrence of "bar" whatsoever,  because
        the assertion (?!foo) is always true when the next three characters are
        "bar". A lookbehind assertion is needed to achieve the other effect.
 
        If you want to force a matching failure at some point in a pattern, the
-       most convenient way to do it is  with  (?!)  because  an  empty  string
-       always  matches, so an assertion that requires there not to be an empty
+       most  convenient  way  to  do  it  is with (?!) because an empty string
+       always matches, so an assertion that requires there not to be an  empty
        string must always fail.  The backtracking control verb (*FAIL) or (*F)
        is a synonym for (?!).
 
    Lookbehind assertions
 
-       Lookbehind  assertions start with (?<= for positive assertions and (?)...) or (?('name')...) to test for a
-       used subpattern by name. For compatibility  with  earlier  versions  of
-       PCRE1,  which had this facility before Perl, the syntax (?(name)...) is
-       also recognized. Note, however, that undelimited  names  consisting  of
-       the  letter  R followed by digits are ambiguous (see the following sec-
+       Perl uses the syntax (?()...) or (?('name')...)  to  test  for  a
+       used  subpattern  by  name.  For compatibility with earlier versions of
+       PCRE1, which had this facility before Perl, the syntax (?(name)...)  is
+       also  recognized.  Note,  however, that undelimited names consisting of
+       the letter R followed by digits are ambiguous (see the  following  sec-
        tion).
 
        Rewriting the above example to use a named subpattern gives this:
 
          (? \( )?    [^()]+    (?() \) )
 
-       If the name used in a condition of this kind is a duplicate,  the  test
-       is  applied to all subpatterns of the same name, and is true if any one
+       If  the  name used in a condition of this kind is a duplicate, the test
+       is applied to all subpatterns of the same name, and is true if any  one
        of them has matched.
 
    Checking for pattern recursion
 
-       "Recursion" in this sense refers to any subroutine-like call  from  one
-       part  of  the  pattern to another, whether or not it is actually recur-
-       sive. See the sections entitled "Recursive patterns"  and  "Subpatterns
+       "Recursion"  in  this sense refers to any subroutine-like call from one
+       part of the pattern to another, whether or not it  is  actually  recur-
+       sive.  See  the sections entitled "Recursive patterns" and "Subpatterns
        as subroutines" below for details of recursion and subpattern calls.
 
-       If  a  condition is the string (R), and there is no subpattern with the
-       name R, the condition is true if matching is currently in  a  recursion
-       or  subroutine  call  to the whole pattern or any subpattern. If digits
-       follow the letter R, and there is no subpattern  with  that  name,  the
+       If a condition is the string (R), and there is no subpattern  with  the
+       name  R,  the condition is true if matching is currently in a recursion
+       or subroutine call to the whole pattern or any  subpattern.  If  digits
+       follow  the  letter  R,  and there is no subpattern with that name, the
        condition is true if the most recent call is into a subpattern with the
-       given number, which must exist somewhere in the overall  pattern.  This
+       given  number,  which must exist somewhere in the overall pattern. This
        is a contrived example that is equivalent to a+b:
 
          ((?(R1)a+|(?1)b))
 
-       However,  in both cases, if there is a subpattern with a matching name,
-       the condition tests for its being set,  as  described  in  the  section
-       above,  instead of testing for recursion. For example, creating a group
-       with the name R1 by adding (?)  to  the  above  pattern  completely
+       However, in both cases, if there is a subpattern with a matching  name,
+       the  condition  tests  for  its  being set, as described in the section
+       above, instead of testing for recursion. For example, creating a  group
+       with  the  name  R1  by  adding (?) to the above pattern completely
        changes its meaning.
 
        If a name preceded by ampersand follows the letter R, for example:
@@ -7750,7 +7758,7 @@ CONDITIONAL SUBPATTERNS
        of that name (which must exist within the pattern).
 
        This condition does not check the entire recursion stack. It tests only
-       the  current  level.  If the name used in a condition of this kind is a
+       the current level. If the name used in a condition of this  kind  is  a
        duplicate, the test is applied to all subpatterns of the same name, and
        is true if any one of them is the most recent recursion.
 
@@ -7759,10 +7767,10 @@ CONDITIONAL SUBPATTERNS
    Defining subpatterns for use by reference only
 
        If the condition is the string (DEFINE), the condition is always false,
-       even if there is a group with the name DEFINE. In this case, there  may
+       even  if there is a group with the name DEFINE. In this case, there may
        be only one alternative in the subpattern. It is always skipped if con-
-       trol reaches this point in the pattern; the idea of DEFINE is  that  it
-       can  be  used  to  define subroutines that can be referenced from else-
+       trol  reaches  this point in the pattern; the idea of DEFINE is that it
+       can be used to define subroutines that can  be  referenced  from  else-
        where. (The use of subroutines is described below.) For example, a pat-
        tern to match an IPv4 address such as "192.168.23.245" could be written
        like this (ignore white space and line breaks):
@@ -7770,97 +7778,97 @@ CONDITIONAL SUBPATTERNS
          (?(DEFINE) (? 2[0-4]\d | 25[0-5] | 1\d\d | [1-9]?\d) )
          \b (?&byte) (\.(?&byte)){3} \b
 
-       The first part of the pattern is a DEFINE group inside which a  another
-       group  named "byte" is defined. This matches an individual component of
-       an IPv4 address (a number less than 256). When  matching  takes  place,
-       this  part  of  the pattern is skipped because DEFINE acts like a false
-       condition. The rest of the pattern uses references to the  named  group
-       to  match the four dot-separated components of an IPv4 address, insist-
+       The  first part of the pattern is a DEFINE group inside which a another
+       group named "byte" is defined. This matches an individual component  of
+       an  IPv4  address  (a number less than 256). When matching takes place,
+       this part of the pattern is skipped because DEFINE acts  like  a  false
+       condition.  The  rest of the pattern uses references to the named group
+       to match the four dot-separated components of an IPv4 address,  insist-
        ing on a word boundary at each end.
 
    Checking the PCRE2 version
 
-       Programs that link with a PCRE2 library can check the version by  call-
-       ing  pcre2_config()  with  appropriate arguments. Users of applications
-       that do not have access to the underlying code cannot do this.  A  spe-
-       cial  "condition" called VERSION exists to allow such users to discover
+       Programs  that link with a PCRE2 library can check the version by call-
+       ing pcre2_config() with appropriate arguments.  Users  of  applications
+       that  do  not have access to the underlying code cannot do this. A spe-
+       cial "condition" called VERSION exists to allow such users to  discover
        which version of PCRE2 they are dealing with by using this condition to
-       match  a string such as "yesno". VERSION must be followed either by "="
+       match a string such as "yesno". VERSION must be followed either by  "="
        or ">=" and a version number.  For example:
 
          (?(VERSION>=10.4)yes|no)
 
-       This pattern matches "yes" if the PCRE2 version is greater or equal  to
-       10.4,  or "no" otherwise. The fractional part of the version number may
+       This  pattern matches "yes" if the PCRE2 version is greater or equal to
+       10.4, or "no" otherwise. The fractional part of the version number  may
        not contain more than two digits.
 
    Assertion conditions
 
-       If the condition is not in any of the above  formats,  it  must  be  an
-       assertion.   This may be a positive or negative lookahead or lookbehind
-       assertion. Consider  this  pattern,  again  containing  non-significant
+       If  the  condition  is  not  in any of the above formats, it must be an
+       assertion.  This may be a positive or negative lookahead or  lookbehind
+       assertion.  Consider  this  pattern,  again  containing non-significant
        white space, and with the two alternatives on the second line:
 
          (?(?=[^a-z]*[a-z])
          \d{2}-[a-z]{3}-\d{2}  |  \d{2}-\d{2}-\d{2} )
 
-       The  condition  is  a  positive  lookahead  assertion  that  matches an
-       optional sequence of non-letters followed by a letter. In other  words,
-       it  tests  for the presence of at least one letter in the subject. If a
-       letter is found, the subject is matched against the first  alternative;
-       otherwise  it  is  matched  against  the  second.  This pattern matches
-       strings in one of the two forms dd-aaa-dd or dd-dd-dd,  where  aaa  are
+       The condition  is  a  positive  lookahead  assertion  that  matches  an
+       optional  sequence of non-letters followed by a letter. In other words,
+       it tests for the presence of at least one letter in the subject.  If  a
+       letter  is found, the subject is matched against the first alternative;
+       otherwise it is  matched  against  the  second.  This  pattern  matches
+       strings  in  one  of the two forms dd-aaa-dd or dd-dd-dd, where aaa are
        letters and dd are digits.
 
-       When  an  assertion that is a condition contains capturing subpatterns,
-       any capturing that occurs in a matching branch is retained  afterwards,
+       When an assertion that is a condition contains  capturing  subpatterns,
+       any  capturing that occurs in a matching branch is retained afterwards,
        for both positive and negative assertions, because matching always con-
        tinues after the assertion, whether it succeeds or fails. (Compare non-
-       conditional  assertions,  when  captures are retained only for positive
+       conditional assertions, when captures are retained  only  for  positive
        assertions that succeed.)
 
 
 COMMENTS
 
        There are two ways of including comments in patterns that are processed
-       by  PCRE2.  In  both  cases,  the start of the comment must not be in a
-       character class, nor in the middle of any  other  sequence  of  related
-       characters  such  as (?: or a subpattern name or number. The characters
+       by PCRE2. In both cases, the start of the comment  must  not  be  in  a
+       character  class,  nor  in  the middle of any other sequence of related
+       characters such as (?: or a subpattern name or number.  The  characters
        that make up a comment play no part in the pattern matching.
 
-       The sequence (?# marks the start of a comment that continues up to  the
-       next  closing parenthesis. Nested parentheses are not permitted. If the
-       PCRE2_EXTENDED option is set, an unescaped # character also  introduces
-       a  comment,  which in this case continues to immediately after the next
-       newline character or character sequence in the pattern.  Which  charac-
-       ters  are  interpreted as newlines is controlled by an option passed to
-       the compiling function or by a special sequence at  the  start  of  the
-       pattern,  as  described  in  the section entitled "Newline conventions"
-       above. Note that the end of this type of comment is a  literal  newline
-       sequence  in  the  pattern; escape sequences that happen to represent a
-       newline  do  not  count.  For  example,  consider  this  pattern   when
-       PCRE2_EXTENDED  is  set,  and  the default newline convention (a single
+       The  sequence (?# marks the start of a comment that continues up to the
+       next closing parenthesis. Nested parentheses are not permitted. If  the
+       PCRE2_EXTENDED  option is set, an unescaped # character also introduces
+       a comment, which in this case continues to immediately after  the  next
+       newline  character  or character sequence in the pattern. Which charac-
+       ters are interpreted as newlines is controlled by an option  passed  to
+       the  compiling  function  or  by a special sequence at the start of the
+       pattern, as described in the  section  entitled  "Newline  conventions"
+       above.  Note  that the end of this type of comment is a literal newline
+       sequence in the pattern; escape sequences that happen  to  represent  a
+       newline   do  not  count.  For  example,  consider  this  pattern  when
+       PCRE2_EXTENDED is set, and the default  newline  convention  (a  single
        linefeed character) is in force:
 
          abc #comment \n still comment
 
-       On encountering the # character, pcre2_compile() skips  along,  looking
-       for  a newline in the pattern. The sequence \n is still literal at this
-       stage, so it does not terminate the comment. Only an  actual  character
+       On  encountering  the # character, pcre2_compile() skips along, looking
+       for a newline in the pattern. The sequence \n is still literal at  this
+       stage,  so  it does not terminate the comment. Only an actual character
        with the code value 0x0a (the default newline) does so.
 
 
 RECURSIVE PATTERNS
 
-       Consider  the problem of matching a string in parentheses, allowing for
-       unlimited nested parentheses. Without the use of  recursion,  the  best
-       that  can  be  done  is  to use a pattern that matches up to some fixed
-       depth of nesting. It is not possible to  handle  an  arbitrary  nesting
+       Consider the problem of matching a string in parentheses, allowing  for
+       unlimited  nested  parentheses.  Without the use of recursion, the best
+       that can be done is to use a pattern that  matches  up  to  some  fixed
+       depth  of  nesting.  It  is not possible to handle an arbitrary nesting
        depth.
 
        For some time, Perl has provided a facility that allows regular expres-
-       sions to recurse (amongst other things). It does this by  interpolating
-       Perl  code in the expression at run time, and the code can refer to the
+       sions  to recurse (amongst other things). It does this by interpolating
+       Perl code in the expression at run time, and the code can refer to  the
        expression itself. A Perl pattern using code interpolation to solve the
        parentheses problem can be created like this:
 
@@ -7870,179 +7878,179 @@ RECURSIVE PATTERNS
        refers recursively to the pattern in which it appears.
 
        Obviously,  PCRE2  cannot  support  the  interpolation  of  Perl  code.
-       Instead,  it  supports  special syntax for recursion of the entire pat-
+       Instead, it supports special syntax for recursion of  the  entire  pat-
        tern, and also for individual subpattern recursion. After its introduc-
-       tion  in  PCRE1  and  Python,  this  kind of recursion was subsequently
+       tion in PCRE1 and Python,  this  kind  of  recursion  was  subsequently
        introduced into Perl at release 5.10.
 
-       A special item that consists of (? followed by a  number  greater  than
-       zero  and  a  closing parenthesis is a recursive subroutine call of the
-       subpattern of the given number, provided that  it  occurs  inside  that
-       subpattern.  (If  not,  it is a non-recursive subroutine call, which is
-       described in the next section.) The special item  (?R)  or  (?0)  is  a
+       A  special  item  that consists of (? followed by a number greater than
+       zero and a closing parenthesis is a recursive subroutine  call  of  the
+       subpattern  of  the  given  number, provided that it occurs inside that
+       subpattern. (If not, it is a non-recursive subroutine  call,  which  is
+       described  in  the  next  section.)  The special item (?R) or (?0) is a
        recursive call of the entire regular expression.
 
-       This  PCRE2  pattern  solves the nested parentheses problem (assume the
+       This PCRE2 pattern solves the nested parentheses  problem  (assume  the
        PCRE2_EXTENDED option is set so that white space is ignored):
 
          \( ( [^()]++ | (?R) )* \)
 
-       First it matches an opening parenthesis. Then it matches any number  of
-       substrings  which  can  either  be  a sequence of non-parentheses, or a
-       recursive match of the pattern itself (that is, a  correctly  parenthe-
+       First  it matches an opening parenthesis. Then it matches any number of
+       substrings which can either be a  sequence  of  non-parentheses,  or  a
+       recursive  match  of the pattern itself (that is, a correctly parenthe-
        sized substring).  Finally there is a closing parenthesis. Note the use
        of a possessive quantifier to avoid backtracking into sequences of non-
        parentheses.
 
-       If  this  were  part of a larger pattern, you would not want to recurse
+       If this were part of a larger pattern, you would not  want  to  recurse
        the entire pattern, so instead you could use this:
 
          ( \( ( [^()]++ | (?1) )* \) )
 
-       We have put the pattern into parentheses, and caused the  recursion  to
+       We  have  put the pattern into parentheses, and caused the recursion to
        refer to them instead of the whole pattern.
 
-       In  a  larger  pattern,  keeping  track  of  parenthesis numbers can be
-       tricky. This is made easier by the use of relative references.  Instead
+       In a larger pattern,  keeping  track  of  parenthesis  numbers  can  be
+       tricky.  This is made easier by the use of relative references. Instead
        of (?1) in the pattern above you can write (?-2) to refer to the second
-       most recently opened parentheses  preceding  the  recursion.  In  other
-       words,  a  negative  number counts capturing parentheses leftwards from
+       most  recently  opened  parentheses  preceding  the recursion. In other
+       words, a negative number counts capturing  parentheses  leftwards  from
        the point at which it is encountered.
 
        Be aware however, that if duplicate subpattern numbers are in use, rel-
-       ative  references refer to the earliest subpattern with the appropriate
+       ative references refer to the earliest subpattern with the  appropriate
        number. Consider, for example:
 
          (?|(a)|(b)) (c) (?-2)
 
-       The first two capturing groups (a) and (b) are  both  numbered  1,  and
-       group  (c)  is  number  2. When the reference (?-2) is encountered, the
+       The  first  two  capturing  groups (a) and (b) are both numbered 1, and
+       group (c) is number 2. When the reference  (?-2)  is  encountered,  the
        second most recently opened parentheses has the number 1, but it is the
-       first  such  group  (the (a) group) to which the recursion refers. This
-       would be the same if an absolute reference  (?1)  was  used.  In  other
-       words,  relative  references are just a shorthand for computing a group
+       first such group (the (a) group) to which the  recursion  refers.  This
+       would  be  the  same  if  an absolute reference (?1) was used. In other
+       words, relative references are just a shorthand for computing  a  group
        number.
 
-       It is also possible to refer to  subsequently  opened  parentheses,  by
-       writing  references  such  as (?+2). However, these cannot be recursive
-       because the reference is not inside the  parentheses  that  are  refer-
-       enced.  They are always non-recursive subroutine calls, as described in
+       It  is  also  possible  to refer to subsequently opened parentheses, by
+       writing references such as (?+2). However, these  cannot  be  recursive
+       because  the  reference  is  not inside the parentheses that are refer-
+       enced. They are always non-recursive subroutine calls, as described  in
        the next section.
 
-       An alternative approach is to use named parentheses.  The  Perl  syntax
-       for  this  is  (?&name);  PCRE1's earlier syntax (?P>name) is also sup-
+       An  alternative  approach  is to use named parentheses. The Perl syntax
+       for this is (?&name); PCRE1's earlier syntax  (?P>name)  is  also  sup-
        ported. We could rewrite the above example as follows:
 
          (? \( ( [^()]++ | (?&pn) )* \) )
 
-       If there is more than one subpattern with the same name,  the  earliest
+       If  there  is more than one subpattern with the same name, the earliest
        one is used.
 
        The example pattern that we have been looking at contains nested unlim-
-       ited repeats, and so the use of a possessive  quantifier  for  matching
-       strings  of  non-parentheses  is important when applying the pattern to
+       ited  repeats,  and  so the use of a possessive quantifier for matching
+       strings of non-parentheses is important when applying  the  pattern  to
        strings that do not match. For example, when this pattern is applied to
 
          (aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa()
 
-       it yields "no match" quickly. However, if a  possessive  quantifier  is
-       not  used, the match runs for a very long time indeed because there are
-       so many different ways the + and * repeats can carve  up  the  subject,
+       it  yields  "no  match" quickly. However, if a possessive quantifier is
+       not used, the match runs for a very long time indeed because there  are
+       so  many  different  ways the + and * repeats can carve up the subject,
        and all have to be tested before failure can be reported.
 
-       At  the  end  of a match, the values of capturing parentheses are those
-       from the outermost level. If you want to obtain intermediate values,  a
+       At the end of a match, the values of capturing  parentheses  are  those
+       from  the outermost level. If you want to obtain intermediate values, a
        callout function can be used (see below and the pcre2callout documenta-
        tion). If the pattern above is matched against
 
          (ab(cd)ef)
 
-       the value for the inner capturing parentheses  (numbered  2)  is  "ef",
-       which  is the last value taken on at the top level. If a capturing sub-
-       pattern is not matched at the top level, its final  captured  value  is
-       unset,  even  if  it was (temporarily) set at a deeper level during the
+       the  value  for  the  inner capturing parentheses (numbered 2) is "ef",
+       which is the last value taken on at the top level. If a capturing  sub-
+       pattern  is  not  matched at the top level, its final captured value is
+       unset, even if it was (temporarily) set at a deeper  level  during  the
        matching process.
 
        If there are more than 15 capturing parentheses in a pattern, PCRE2 has
-       to  obtain extra memory from the heap to store data during a recursion.
-       If  no  memory  can   be   obtained,   the   match   fails   with   the
+       to obtain extra memory from the heap to store data during a  recursion.
+       If   no   memory   can   be   obtained,   the   match  fails  with  the
        PCRE2_ERROR_NOMEMORY error.
 
-       Do  not  confuse  the (?R) item with the condition (R), which tests for
-       recursion.  Consider this pattern, which matches text in  angle  brack-
-       ets,  allowing for arbitrary nesting. Only digits are allowed in nested
-       brackets (that is, when recursing), whereas any characters are  permit-
+       Do not confuse the (?R) item with the condition (R),  which  tests  for
+       recursion.   Consider  this pattern, which matches text in angle brack-
+       ets, allowing for arbitrary nesting. Only digits are allowed in  nested
+       brackets  (that is, when recursing), whereas any characters are permit-
        ted at the outer level.
 
          < (?: (?(R) \d++  | [^<>]*+) | (?R)) * >
 
-       In  this  pattern, (?(R) is the start of a conditional subpattern, with
-       two different alternatives for the recursive and  non-recursive  cases.
+       In this pattern, (?(R) is the start of a conditional  subpattern,  with
+       two  different  alternatives for the recursive and non-recursive cases.
        The (?R) item is the actual recursive call.
 
    Differences in recursion processing between PCRE2 and Perl
 
        Some former differences between PCRE2 and Perl no longer exist.
 
-       Before  release 10.30, recursion processing in PCRE2 differed from Perl
-       in that a recursive subpattern call was always  treated  as  an  atomic
-       group.  That is, once it had matched some of the subject string, it was
-       never re-entered, even if it contained untried alternatives  and  there
-       was  a  subsequent matching failure. (Historical note: PCRE implemented
+       Before release 10.30, recursion processing in PCRE2 differed from  Perl
+       in  that  a  recursive  subpattern call was always treated as an atomic
+       group. That is, once it had matched some of the subject string, it  was
+       never  re-entered,  even if it contained untried alternatives and there
+       was a subsequent matching failure. (Historical note:  PCRE  implemented
        recursion before Perl did.)
 
-       Starting with release 10.30, recursive subroutine calls are  no  longer
+       Starting  with  release 10.30, recursive subroutine calls are no longer
        treated as atomic. That is, they can be re-entered to try unused alter-
-       natives if there is a matching failure later in the  pattern.  This  is
-       now  compatible  with the way Perl works. If you want a subroutine call
+       natives  if  there  is a matching failure later in the pattern. This is
+       now compatible with the way Perl works. If you want a  subroutine  call
        to be atomic, you must explicitly enclose it in an atomic group.
 
-       Supporting backtracking into recursions  simplifies  certain  types  of
+       Supporting  backtracking  into  recursions  simplifies certain types of
        recursive  pattern.  For  example,  this  pattern  matches  palindromic
        strings:
 
          ^((.)(?1)\2|.?)$
 
-       The second branch in the group matches a single  central  character  in
-       the  palindrome  when there are an odd number of characters, or nothing
-       when there are an even number of characters, but in order  to  work  it
-       has  to  be  able  to  try the second case when the rest of the pattern
+       The  second  branch  in the group matches a single central character in
+       the palindrome when there are an odd number of characters,  or  nothing
+       when  there  are  an even number of characters, but in order to work it
+       has to be able to try the second case when  the  rest  of  the  pattern
        match fails. If you want to match typical palindromic phrases, the pat-
-       tern  has  to  ignore  all  non-word characters, which can be done like
+       tern has to ignore all non-word characters,  which  can  be  done  like
        this:
 
          ^\W*+((.)\W*+(?1)\W*+\2|\W*+.?)\W*+$
 
-       If run with the PCRE2_CASELESS option,  this  pattern  matches  phrases
-       such  as "A man, a plan, a canal: Panama!". Note the use of the posses-
-       sive quantifier *+ to avoid backtracking  into  sequences  of  non-word
+       If  run  with  the  PCRE2_CASELESS option, this pattern matches phrases
+       such as "A man, a plan, a canal: Panama!". Note the use of the  posses-
+       sive  quantifier  *+  to  avoid backtracking into sequences of non-word
        characters. Without this, PCRE2 takes a great deal longer (ten times or
-       more) to match typical phrases, and Perl takes so long that  you  think
+       more)  to  match typical phrases, and Perl takes so long that you think
        it has gone into a loop.
 
-       Another  way  in which PCRE2 and Perl used to differ in their recursion
-       processing is in the handling of captured  values.  Formerly  in  Perl,
-       when  a  subpattern  was called recursively or as a subpattern (see the
-       next section), it had no access to any values that were  captured  out-
-       side  the  recursion,  whereas in PCRE2 these values can be referenced.
+       Another way in which PCRE2 and Perl used to differ in  their  recursion
+       processing  is  in  the  handling of captured values. Formerly in Perl,
+       when a subpattern was called recursively or as a  subpattern  (see  the
+       next  section),  it had no access to any values that were captured out-
+       side the recursion, whereas in PCRE2 these values  can  be  referenced.
        Consider this pattern:
 
          ^(.)(\1|a(?2))
 
-       This pattern matches "bab". The first capturing parentheses match  "b",
-       then  in  the  second  group, when the back reference \1 fails to match
-       "b", the second alternative matches  "a"  and  then  recurses.  In  the
-       recursion,  \1 does now match "b" and so the whole match succeeds. This
-       match used to fail in Perl, but in later versions (I  tried  5.024)  it
+       This  pattern matches "bab". The first capturing parentheses match "b",
+       then in the second group, when the back reference  \1  fails  to  match
+       "b",  the  second  alternative  matches  "a"  and then recurses. In the
+       recursion, \1 does now match "b" and so the whole match succeeds.  This
+       match  used  to  fail in Perl, but in later versions (I tried 5.024) it
        now works.
 
 
 SUBPATTERNS AS SUBROUTINES
 
-       If  the  syntax for a recursive subpattern call (either by number or by
-       name) is used outside the parentheses to which it refers,  it  operates
-       like  a subroutine in a programming language. The called subpattern may
-       be defined before or after the reference. A numbered reference  can  be
+       If the syntax for a recursive subpattern call (either by number  or  by
+       name)  is  used outside the parentheses to which it refers, it operates
+       like a subroutine in a programming language. The called subpattern  may
+       be  defined  before or after the reference. A numbered reference can be
        absolute or relative, as in these examples:
 
          (...(absolute)...)...(?2)...
@@ -8053,102 +8061,102 @@ SUBPATTERNS AS SUBROUTINES
 
          (sens|respons)e and \1ibility
 
-       matches  "sense and sensibility" and "response and responsibility", but
+       matches "sense and sensibility" and "response and responsibility",  but
        not "sense and responsibility". If instead the pattern
 
          (sens|respons)e and (?1)ibility
 
-       is used, it does match "sense and responsibility" as well as the  other
-       two  strings.  Another  example  is  given  in the discussion of DEFINE
+       is  used, it does match "sense and responsibility" as well as the other
+       two strings. Another example is  given  in  the  discussion  of  DEFINE
        above.
 
-       Like recursions, subroutine calls used to be  treated  as  atomic,  but
-       this  changed  at  PCRE2 release 10.30, so backtracking into subroutine
-       calls can now occur. However, any capturing parentheses  that  are  set
+       Like  recursions,  subroutine  calls  used to be treated as atomic, but
+       this changed at PCRE2 release 10.30, so  backtracking  into  subroutine
+       calls  can  now  occur. However, any capturing parentheses that are set
        during the subroutine call revert to their previous values afterwards.
 
-       Processing  options  such as case-independence are fixed when a subpat-
-       tern is defined, so if it is used as a subroutine, such options  cannot
+       Processing options such as case-independence are fixed when  a  subpat-
+       tern  is defined, so if it is used as a subroutine, such options cannot
        be changed for different calls. For example, consider this pattern:
 
          (abc)(?i:(?-1))
 
-       It  matches  "abcabc". It does not match "abcABC" because the change of
+       It matches "abcabc". It does not match "abcABC" because the  change  of
        processing option does not affect the called subpattern.
 
 
 ONIGURUMA SUBROUTINE SYNTAX
 
-       For compatibility with Oniguruma, the non-Perl syntax \g followed by  a
+       For  compatibility with Oniguruma, the non-Perl syntax \g followed by a
        name or a number enclosed either in angle brackets or single quotes, is
-       an alternative syntax for referencing a  subpattern  as  a  subroutine,
-       possibly  recursively. Here are two of the examples used above, rewrit-
+       an  alternative  syntax  for  referencing a subpattern as a subroutine,
+       possibly recursively. Here are two of the examples used above,  rewrit-
        ten using this syntax:
 
          (? \( ( (?>[^()]+) | \g )* \) )
          (sens|respons)e and \g'1'ibility
 
-       PCRE2 supports an extension to Oniguruma: if a number is preceded by  a
+       PCRE2  supports an extension to Oniguruma: if a number is preceded by a
        plus or a minus sign it is taken as a relative reference. For example:
 
          (abc)(?i:\g<-1>)
 
-       Note  that \g{...} (Perl syntax) and \g<...> (Oniguruma syntax) are not
-       synonymous. The former is a back reference; the latter is a  subroutine
+       Note that \g{...} (Perl syntax) and \g<...> (Oniguruma syntax) are  not
+       synonymous.  The former is a back reference; the latter is a subroutine
        call.
 
 
 CALLOUTS
 
        Perl has a feature whereby using the sequence (?{...}) causes arbitrary
-       Perl code to be obeyed in the middle of matching a regular  expression.
+       Perl  code to be obeyed in the middle of matching a regular expression.
        This makes it possible, amongst other things, to extract different sub-
        strings that match the same pair of parentheses when there is a repeti-
        tion.
 
-       PCRE2  provides  a  similar feature, but of course it cannot obey arbi-
-       trary Perl code. The feature is called "callout". The caller  of  PCRE2
-       provides  an  external  function  by putting its entry point in a match
-       context using the function pcre2_set_callout(), and then  passing  that
-       context  to  pcre2_match() or pcre2_dfa_match(). If no match context is
+       PCRE2 provides a similar feature, but of course it  cannot  obey  arbi-
+       trary  Perl  code. The feature is called "callout". The caller of PCRE2
+       provides an external function by putting its entry  point  in  a  match
+       context  using  the function pcre2_set_callout(), and then passing that
+       context to pcre2_match() or pcre2_dfa_match(). If no match  context  is
        passed, or if the callout entry point is set to NULL, callouts are dis-
        abled.
 
-       Within  a  regular expression, (?C) indicates a point at which the
-       external function is to be called. There  are  two  kinds  of  callout:
-       those  with a numerical argument and those with a string argument. (?C)
-       on its own with no argument is treated as (?C0). A  numerical  argument
-       allows  the  application  to  distinguish  between  different callouts.
-       String arguments were added for release 10.20 to make it  possible  for
-       script  languages that use PCRE2 to embed short scripts within patterns
+       Within a regular expression, (?C) indicates a point at  which  the
+       external  function  is  to  be  called. There are two kinds of callout:
+       those with a numerical argument and those with a string argument.  (?C)
+       on  its  own with no argument is treated as (?C0). A numerical argument
+       allows the  application  to  distinguish  between  different  callouts.
+       String  arguments  were added for release 10.20 to make it possible for
+       script languages that use PCRE2 to embed short scripts within  patterns
        in a similar way to Perl.
 
        During matching, when PCRE2 reaches a callout point, the external func-
-       tion  is  called.  It is provided with the number or string argument of
-       the callout, the position in the pattern, and one item of data that  is
+       tion is called. It is provided with the number or  string  argument  of
+       the  callout, the position in the pattern, and one item of data that is
        also set in the match block. The callout function may cause matching to
        proceed, to backtrack, or to fail.
 
-       By default, PCRE2 implements a  number  of  optimizations  at  matching
-       time,  and  one  side-effect is that sometimes callouts are skipped. If
-       you need all possible callouts to happen, you need to set options  that
-       disable  the relevant optimizations. More details, including a complete
-       description of the programming interface to the callout  function,  are
+       By  default,  PCRE2  implements  a  number of optimizations at matching
+       time, and one side-effect is that sometimes callouts  are  skipped.  If
+       you  need all possible callouts to happen, you need to set options that
+       disable the relevant optimizations. More details, including a  complete
+       description  of  the programming interface to the callout function, are
        given in the pcre2callout documentation.
 
    Callouts with numerical arguments
 
-       If  you  just  want  to  have  a means of identifying different callout
-       points, put a number less than 256 after the  letter  C.  For  example,
+       If you just want to have  a  means  of  identifying  different  callout
+       points,  put  a  number  less than 256 after the letter C. For example,
        this pattern has two callout points:
 
          (?C1)abc(?C2)def
 
-       If  the PCRE2_AUTO_CALLOUT flag is passed to pcre2_compile(), numerical
-       callouts are automatically installed before each item in  the  pattern.
-       They  are all numbered 255. If there is a conditional group in the pat-
+       If the PCRE2_AUTO_CALLOUT flag is passed to pcre2_compile(),  numerical
+       callouts  are  automatically installed before each item in the pattern.
+       They are all numbered 255. If there is a conditional group in the  pat-
        tern whose condition is an assertion, an additional callout is inserted
-       just  before the condition. An explicit callout may also be set at this
+       just before the condition. An explicit callout may also be set at  this
        position, as in this example:
 
          (?(?C9)(?=a)abc|def)
@@ -8158,60 +8166,60 @@ CALLOUTS
 
    Callouts with string arguments
 
-       A  delimited  string may be used instead of a number as a callout argu-
-       ment. The starting delimiter must be one of ` ' " ^ % #  $  {  and  the
+       A delimited string may be used instead of a number as a  callout  argu-
+       ment.  The  starting  delimiter  must be one of ` ' " ^ % # $ { and the
        ending delimiter is the same as the start, except for {, where the end-
-       ing delimiter is }. If  the  ending  delimiter  is  needed  within  the
+       ing  delimiter  is  }.  If  the  ending  delimiter is needed within the
        string, it must be doubled. For example:
 
          (?C'ab ''c'' d')xyz(?C{any text})pqr
 
-       The  doubling  is  removed  before  the string is passed to the callout
+       The doubling is removed before the string  is  passed  to  the  callout
        function.
 
 
 BACKTRACKING CONTROL
 
-       There are a number of special  "Backtracking  Control  Verbs"  (to  use
-       Perl's  terminology)  that  modify the behaviour of backtracking during
-       matching. They are generally of the form (*VERB) or (*VERB:NAME).  Some
-       verbs  take  either  form,  possibly  behaving differently depending on
+       There  are  a  number  of  special "Backtracking Control Verbs" (to use
+       Perl's terminology) that modify the behaviour  of  backtracking  during
+       matching.  They are generally of the form (*VERB) or (*VERB:NAME). Some
+       verbs take either form,  possibly  behaving  differently  depending  on
        whether or not a name is present.
 
-       By default, for compatibility with Perl, a  name  is  any  sequence  of
+       By  default,  for  compatibility  with  Perl, a name is any sequence of
        characters that does not include a closing parenthesis. The name is not
-       processed in any way, and it is  not  possible  to  include  a  closing
-       parenthesis   in  the  name.   This  can  be  changed  by  setting  the
-       PCRE2_ALT_VERBNAMES option, but the result is no  longer  Perl-compati-
+       processed  in  any  way,  and  it  is not possible to include a closing
+       parenthesis  in  the  name.   This  can  be  changed  by  setting   the
+       PCRE2_ALT_VERBNAMES  option,  but the result is no longer Perl-compati-
        ble.
 
-       When  PCRE2_ALT_VERBNAMES  is  set,  backslash processing is applied to
-       verb names and only an unescaped  closing  parenthesis  terminates  the
-       name.  However, the only backslash items that are permitted are \Q, \E,
-       and sequences such as \x{100} that define character code points.  Char-
+       When PCRE2_ALT_VERBNAMES is set, backslash  processing  is  applied  to
+       verb  names  and  only  an unescaped closing parenthesis terminates the
+       name. However, the only backslash items that are permitted are \Q,  \E,
+       and  sequences such as \x{100} that define character code points. Char-
        acter type escapes such as \d are faulted.
 
        A closing parenthesis can be included in a name either as \) or between
-       \Q and \E. In addition to backslash processing, if  the  PCRE2_EXTENDED
-       option  is also set, unescaped whitespace in verb names is skipped, and
-       #-comments are recognized, exactly as  in  the  rest  of  the  pattern.
+       \Q  and  \E. In addition to backslash processing, if the PCRE2_EXTENDED
+       option is also set, unescaped whitespace in verb names is skipped,  and
+       #-comments  are  recognized,  exactly  as  in  the rest of the pattern.
        PCRE2_EXTENDED does not affect verb names unless PCRE2_ALT_VERBNAMES is
        also set.
 
-       The maximum length of a name is 255 in the 8-bit library and  65535  in
-       the  16-bit and 32-bit libraries. If the name is empty, that is, if the
-       closing parenthesis immediately follows the colon, the effect is as  if
+       The  maximum  length of a name is 255 in the 8-bit library and 65535 in
+       the 16-bit and 32-bit libraries. If the name is empty, that is, if  the
+       closing  parenthesis immediately follows the colon, the effect is as if
        the colon were not there. Any number of these verbs may occur in a pat-
        tern.
 
-       Since these verbs are specifically related  to  backtracking,  most  of
-       them  can be used only when the pattern is to be matched using the tra-
+       Since  these  verbs  are  specifically related to backtracking, most of
+       them can be used only when the pattern is to be matched using the  tra-
        ditional matching function, because that uses a backtracking algorithm.
-       With  the  exception  of (*FAIL), which behaves like a failing negative
+       With the exception of (*FAIL), which behaves like  a  failing  negative
        assertion, the backtracking control verbs cause an error if encountered
        by the DFA matching function.
 
-       The  behaviour  of  these  verbs in repeated groups, assertions, and in
+       The behaviour of these verbs in repeated  groups,  assertions,  and  in
        subpatterns called as subroutines (whether or not recursively) is docu-
        mented below.
 
@@ -8219,71 +8227,71 @@ BACKTRACKING CONTROL
 
        PCRE2 contains some optimizations that are used to speed up matching by
        running some checks at the start of each match attempt. For example, it
-       may  know  the minimum length of matching subject, or that a particular
+       may know the minimum length of matching subject, or that  a  particular
        character must be present. When one of these optimizations bypasses the
-       running  of  a  match,  any  included  backtracking  verbs will not, of
+       running of a match,  any  included  backtracking  verbs  will  not,  of
        course, be processed. You can suppress the start-of-match optimizations
-       by  setting  the PCRE2_NO_START_OPTIMIZE option when calling pcre2_com-
-       pile(), or by starting the pattern with (*NO_START_OPT). There is  more
+       by setting the PCRE2_NO_START_OPTIMIZE option when  calling  pcre2_com-
+       pile(),  or by starting the pattern with (*NO_START_OPT). There is more
        discussion of this option in the section entitled "Compiling a pattern"
        in the pcre2api documentation.
 
-       Experiments with Perl suggest that it too  has  similar  optimizations,
+       Experiments  with  Perl  suggest that it too has similar optimizations,
        sometimes leading to anomalous results.
 
    Verbs that act immediately
 
-       The  following  verbs act as soon as they are encountered. They may not
+       The following verbs act as soon as they are encountered. They  may  not
        be followed by a name.
 
           (*ACCEPT)
 
-       This verb causes the match to end successfully, skipping the  remainder
-       of  the pattern. However, when it is inside a subpattern that is called
-       as a subroutine, only that subpattern is ended  successfully.  Matching
+       This  verb causes the match to end successfully, skipping the remainder
+       of the pattern. However, when it is inside a subpattern that is  called
+       as  a  subroutine, only that subpattern is ended successfully. Matching
        then continues at the outer level. If (*ACCEPT) in triggered in a posi-
-       tive assertion, the assertion succeeds; in a  negative  assertion,  the
+       tive  assertion,  the  assertion succeeds; in a negative assertion, the
        assertion fails.
 
-       If  (*ACCEPT)  is inside capturing parentheses, the data so far is cap-
+       If (*ACCEPT) is inside capturing parentheses, the data so far  is  cap-
        tured. For example:
 
          A((?:A|B(*ACCEPT)|C)D)
 
-       This matches "AB", "AAD", or "ACD"; when it matches "AB", "B"  is  cap-
+       This  matches  "AB", "AAD", or "ACD"; when it matches "AB", "B" is cap-
        tured by the outer parentheses.
 
          (*FAIL) or (*F)
 
-       This  verb causes a matching failure, forcing backtracking to occur. It
-       is equivalent to (?!) but easier to read. The Perl documentation  notes
-       that  it  is  probably  useful only when combined with (?{}) or (??{}).
-       Those are, of course, Perl features that are not present in PCRE2.  The
-       nearest  equivalent is the callout feature, as for example in this pat-
+       This verb causes a matching failure, forcing backtracking to occur.  It
+       is  equivalent to (?!) but easier to read. The Perl documentation notes
+       that it is probably useful only when combined  with  (?{})  or  (??{}).
+       Those  are, of course, Perl features that are not present in PCRE2. The
+       nearest equivalent is the callout feature, as for example in this  pat-
        tern:
 
          a+(?C)(*FAIL)
 
-       A match with the string "aaaa" always fails, but the callout  is  taken
+       A  match  with the string "aaaa" always fails, but the callout is taken
        before each backtrack happens (in this example, 10 times).
 
    Recording which path was taken
 
-       There  is  one  verb  whose  main  purpose  is to track how a match was
-       arrived at, though it also has a  secondary  use  in  conjunction  with
+       There is one verb whose main purpose  is  to  track  how  a  match  was
+       arrived  at,  though  it  also  has a secondary use in conjunction with
        advancing the match starting point (see (*SKIP) below).
 
          (*MARK:NAME) or (*:NAME)
 
-       A  name  is  always  required  with  this  verb.  There  may be as many
-       instances of (*MARK) as you like in a pattern, and their names  do  not
+       A name is always  required  with  this  verb.  There  may  be  as  many
+       instances  of  (*MARK) as you like in a pattern, and their names do not
        have to be unique.
 
-       When  a  match succeeds, the name of the last-encountered (*MARK:NAME),
-       (*PRUNE:NAME), or (*THEN:NAME) on the matching path is passed  back  to
-       the  caller  as  described  in  the section entitled "Other information
-       about the match" in the pcre2api documentation. Here is an  example  of
-       pcre2test  output, where the "mark" modifier requests the retrieval and
+       When a match succeeds, the name of the  last-encountered  (*MARK:NAME),
+       (*PRUNE:NAME),  or  (*THEN:NAME) on the matching path is passed back to
+       the caller as described in  the  section  entitled  "Other  information
+       about  the  match" in the pcre2api documentation. Here is an example of
+       pcre2test output, where the "mark" modifier requests the retrieval  and
        outputting of (*MARK) data:
 
            re> /X(*MARK:A)Y|X(*MARK:B)Z/mark
@@ -8295,72 +8303,72 @@ BACKTRACKING CONTROL
          MK: B
 
        The (*MARK) name is tagged with "MK:" in this output, and in this exam-
-       ple  it indicates which of the two alternatives matched. This is a more
-       efficient way of obtaining this information than putting each  alterna-
+       ple it indicates which of the two alternatives matched. This is a  more
+       efficient  way of obtaining this information than putting each alterna-
        tive in its own capturing parentheses.
 
-       If  a  verb  with a name is encountered in a positive assertion that is
-       true, the name is recorded and passed back if it  is  the  last-encoun-
+       If a verb with a name is encountered in a positive  assertion  that  is
+       true,  the  name  is recorded and passed back if it is the last-encoun-
        tered. This does not happen for negative assertions or failing positive
        assertions.
 
-       After a partial match or a failed match, the last encountered  name  in
+       After  a  partial match or a failed match, the last encountered name in
        the entire match process is returned. For example:
 
            re> /X(*MARK:A)Y|X(*MARK:B)Z/mark
          data> XP
          No match, mark = B
 
-       Note  that  in  this  unanchored  example the mark is retained from the
+       Note that in this unanchored example the  mark  is  retained  from  the
        match attempt that started at the letter "X" in the subject. Subsequent
        match attempts starting at "P" and then with an empty string do not get
        as far as the (*MARK) item, but nevertheless do not reset it.
 
-       If you are interested in  (*MARK)  values  after  failed  matches,  you
-       should  probably  set the PCRE2_NO_START_OPTIMIZE option (see above) to
+       If  you  are  interested  in  (*MARK)  values after failed matches, you
+       should probably set the PCRE2_NO_START_OPTIMIZE option (see  above)  to
        ensure that the match is always attempted.
 
    Verbs that act after backtracking
 
        The following verbs do nothing when they are encountered. Matching con-
-       tinues  with what follows, but if there is no subsequent match, causing
-       a backtrack to the verb, a failure is  forced.  That  is,  backtracking
-       cannot  pass  to the left of the verb. However, when one of these verbs
-       appears inside an atomic group or in an assertion  that  is  true,  its
-       effect  is  confined  to  that  group,  because once the group has been
-       matched, there is never any backtracking into it.  In  this  situation,
-       backtracking  has  to  jump  to  the left of the entire atomic group or
+       tinues with what follows, but if there is no subsequent match,  causing
+       a  backtrack  to  the  verb, a failure is forced. That is, backtracking
+       cannot pass to the left of the verb. However, when one of  these  verbs
+       appears  inside  an  atomic  group or in an assertion that is true, its
+       effect is confined to that group,  because  once  the  group  has  been
+       matched,  there  is  never any backtracking into it. In this situation,
+       backtracking has to jump to the left of  the  entire  atomic  group  or
        assertion.
 
-       These verbs differ in exactly what kind of failure  occurs  when  back-
-       tracking  reaches  them.  The behaviour described below is what happens
-       when the verb is not in a subroutine or an assertion.  Subsequent  sec-
+       These  verbs  differ  in exactly what kind of failure occurs when back-
+       tracking reaches them. The behaviour described below  is  what  happens
+       when  the  verb is not in a subroutine or an assertion. Subsequent sec-
        tions cover these special cases.
 
          (*COMMIT)
 
-       This  verb, which may not be followed by a name, causes the whole match
+       This verb, which may not be followed by a name, causes the whole  match
        to fail outright if there is a later matching failure that causes back-
-       tracking  to  reach  it.  Even if the pattern is unanchored, no further
+       tracking to reach it. Even if the pattern  is  unanchored,  no  further
        attempts to find a match by advancing the starting point take place. If
-       (*COMMIT)  is  the  only backtracking verb that is encountered, once it
-       has been passed pcre2_match() is committed to finding a  match  at  the
+       (*COMMIT) is the only backtracking verb that is  encountered,  once  it
+       has  been  passed  pcre2_match() is committed to finding a match at the
        current starting point, or not at all. For example:
 
          a+(*COMMIT)b
 
-       This  matches  "xxaab" but not "aacaab". It can be thought of as a kind
+       This matches "xxaab" but not "aacaab". It can be thought of as  a  kind
        of dynamic anchor, or "I've started, so I must finish." The name of the
-       most  recently passed (*MARK) in the path is passed back when (*COMMIT)
+       most recently passed (*MARK) in the path is passed back when  (*COMMIT)
        forces a match failure.
 
-       If there is more than one backtracking verb in a pattern,  a  different
-       one  that  follows  (*COMMIT) may be triggered first, so merely passing
+       If  there  is more than one backtracking verb in a pattern, a different
+       one that follows (*COMMIT) may be triggered first,  so  merely  passing
        (*COMMIT) during a match does not always guarantee that a match must be
        at this starting point.
 
-       Note  that  (*COMMIT)  at  the start of a pattern is not the same as an
-       anchor, unless PCRE2's start-of-match optimizations are turned off,  as
+       Note that (*COMMIT) at the start of a pattern is not  the  same  as  an
+       anchor,  unless PCRE2's start-of-match optimizations are turned off, as
        shown in this output from pcre2test:
 
            re> /(*COMMIT)abc/
@@ -8371,213 +8379,213 @@ BACKTRACKING CONTROL
          data> xyzabc
          No match
 
-       For  the first pattern, PCRE2 knows that any match must start with "a",
-       so the optimization skips along the subject to "a" before applying  the
-       pattern  to the first set of data. The match attempt then succeeds. The
-       second pattern disables the optimization that skips along to the  first
-       character.  The  pattern  is  now  applied  starting at "x", and so the
-       (*COMMIT) causes the match to fail without trying  any  other  starting
+       For the first pattern, PCRE2 knows that any match must start with  "a",
+       so  the optimization skips along the subject to "a" before applying the
+       pattern to the first set of data. The match attempt then succeeds.  The
+       second  pattern disables the optimization that skips along to the first
+       character. The pattern is now applied  starting  at  "x",  and  so  the
+       (*COMMIT)  causes  the  match to fail without trying any other starting
        points.
 
          (*PRUNE) or (*PRUNE:NAME)
 
-       This  verb causes the match to fail at the current starting position in
+       This verb causes the match to fail at the current starting position  in
        the subject if there is a later matching failure that causes backtrack-
-       ing  to  reach it. If the pattern is unanchored, the normal "bumpalong"
-       advance to the next starting character then happens.  Backtracking  can
-       occur  as  usual to the left of (*PRUNE), before it is reached, or when
-       matching to the right of (*PRUNE), but if there  is  no  match  to  the
-       right,  backtracking cannot cross (*PRUNE). In simple cases, the use of
-       (*PRUNE) is just an alternative to an atomic group or possessive  quan-
+       ing to reach it. If the pattern is unanchored, the  normal  "bumpalong"
+       advance  to  the next starting character then happens. Backtracking can
+       occur as usual to the left of (*PRUNE), before it is reached,  or  when
+       matching  to  the  right  of  (*PRUNE), but if there is no match to the
+       right, backtracking cannot cross (*PRUNE). In simple cases, the use  of
+       (*PRUNE)  is just an alternative to an atomic group or possessive quan-
        tifier, but there are some uses of (*PRUNE) that cannot be expressed in
-       any other way. In an anchored pattern (*PRUNE) has the same  effect  as
+       any  other  way. In an anchored pattern (*PRUNE) has the same effect as
        (*COMMIT).
 
        The behaviour of (*PRUNE:NAME) is not the same as (*MARK:NAME)(*PRUNE).
        It is like (*MARK:NAME) in that the name is remembered for passing back
-       to  the  caller. However, (*SKIP:NAME) searches only for names set with
+       to the caller. However, (*SKIP:NAME) searches only for names  set  with
        (*MARK), ignoring those set by (*PRUNE) or (*THEN).
 
          (*SKIP)
 
-       This verb, when given without a name, is like (*PRUNE), except that  if
-       the  pattern  is unanchored, the "bumpalong" advance is not to the next
+       This  verb, when given without a name, is like (*PRUNE), except that if
+       the pattern is unanchored, the "bumpalong" advance is not to  the  next
        character, but to the position in the subject where (*SKIP) was encoun-
-       tered.  (*SKIP)  signifies that whatever text was matched leading up to
+       tered. (*SKIP) signifies that whatever text was matched leading  up  to
        it cannot be part of a successful match. Consider:
 
          a+(*SKIP)b
 
-       If the subject is "aaaac...",  after  the  first  match  attempt  fails
-       (starting  at  the  first  character in the string), the starting point
+       If  the  subject  is  "aaaac...",  after  the first match attempt fails
+       (starting at the first character in the  string),  the  starting  point
        skips on to start the next attempt at "c". Note that a possessive quan-
-       tifer  does not have the same effect as this example; although it would
-       suppress backtracking  during  the  first  match  attempt,  the  second
-       attempt  would  start at the second character instead of skipping on to
+       tifer does not have the same effect as this example; although it  would
+       suppress  backtracking  during  the  first  match  attempt,  the second
+       attempt would start at the second character instead of skipping  on  to
        "c".
 
          (*SKIP:NAME)
 
        When (*SKIP) has an associated name, its behaviour is modified. When it
        is triggered, the previous path through the pattern is searched for the
-       most recent (*MARK) that has the  same  name.  If  one  is  found,  the
+       most  recent  (*MARK)  that  has  the  same  name. If one is found, the
        "bumpalong" advance is to the subject position that corresponds to that
        (*MARK) instead of to where (*SKIP) was encountered. If no (*MARK) with
        a matching name is found, the (*SKIP) is ignored.
 
-       Note  that (*SKIP:NAME) searches only for names set by (*MARK:NAME). It
+       Note that (*SKIP:NAME) searches only for names set by (*MARK:NAME).  It
        ignores names that are set by (*PRUNE:NAME) or (*THEN:NAME).
 
          (*THEN) or (*THEN:NAME)
 
-       This verb causes a skip to the next innermost  alternative  when  back-
-       tracking  reaches  it.  That  is,  it  cancels any further backtracking
-       within the current alternative. Its name  comes  from  the  observation
+       This  verb  causes  a skip to the next innermost alternative when back-
+       tracking reaches it. That  is,  it  cancels  any  further  backtracking
+       within  the  current  alternative.  Its name comes from the observation
        that it can be used for a pattern-based if-then-else block:
 
          ( COND1 (*THEN) FOO | COND2 (*THEN) BAR | COND3 (*THEN) BAZ ) ...
 
-       If  the COND1 pattern matches, FOO is tried (and possibly further items
-       after the end of the group if FOO succeeds); on  failure,  the  matcher
-       skips  to  the second alternative and tries COND2, without backtracking
-       into COND1. If that succeeds and BAR fails, COND3 is tried.  If  subse-
-       quently  BAZ fails, there are no more alternatives, so there is a back-
-       track to whatever came before the  entire  group.  If  (*THEN)  is  not
+       If the COND1 pattern matches, FOO is tried (and possibly further  items
+       after  the  end  of the group if FOO succeeds); on failure, the matcher
+       skips to the second alternative and tries COND2,  without  backtracking
+       into  COND1.  If that succeeds and BAR fails, COND3 is tried. If subse-
+       quently BAZ fails, there are no more alternatives, so there is a  back-
+       track  to  whatever  came  before  the  entire group. If (*THEN) is not
        inside an alternation, it acts like (*PRUNE).
 
-       The    behaviour   of   (*THEN:NAME)   is   the   not   the   same   as
-       (*MARK:NAME)(*THEN).  It is like  (*MARK:NAME)  in  that  the  name  is
-       remembered  for  passing  back  to  the  caller.  However, (*SKIP:NAME)
-       searches only for  names  set  with  (*MARK),  ignoring  those  set  by
+       The   behaviour   of   (*THEN:NAME)   is   the   not   the   same    as
+       (*MARK:NAME)(*THEN).   It  is  like  (*MARK:NAME)  in  that the name is
+       remembered for  passing  back  to  the  caller.  However,  (*SKIP:NAME)
+       searches  only  for  names  set  with  (*MARK),  ignoring  those set by
        (*PRUNE) and (*THEN).
 
-       A  subpattern that does not contain a | character is just a part of the
-       enclosing alternative; it is not a nested  alternation  with  only  one
-       alternative.  The effect of (*THEN) extends beyond such a subpattern to
-       the enclosing alternative. Consider this pattern, where A, B, etc.  are
-       complex  pattern fragments that do not contain any | characters at this
+       A subpattern that does not contain a | character is just a part of  the
+       enclosing  alternative;  it  is  not a nested alternation with only one
+       alternative. The effect of (*THEN) extends beyond such a subpattern  to
+       the  enclosing alternative. Consider this pattern, where A, B, etc. are
+       complex pattern fragments that do not contain any | characters at  this
        level:
 
          A (B(*THEN)C) | D
 
-       If A and B are matched, but there is a failure in C, matching does  not
+       If  A and B are matched, but there is a failure in C, matching does not
        backtrack into A; instead it moves to the next alternative, that is, D.
-       However, if the subpattern containing (*THEN) is given an  alternative,
+       However,  if the subpattern containing (*THEN) is given an alternative,
        it behaves differently:
 
          A (B(*THEN)C | (*FAIL)) | D
 
-       The  effect of (*THEN) is now confined to the inner subpattern. After a
+       The effect of (*THEN) is now confined to the inner subpattern. After  a
        failure in C, matching moves to (*FAIL), which causes the whole subpat-
-       tern  to  fail  because  there are no more alternatives to try. In this
+       tern to fail because there are no more alternatives  to  try.  In  this
        case, matching does now backtrack into A.
 
-       Note that a conditional subpattern is  not  considered  as  having  two
-       alternatives,  because  only  one  is  ever used. In other words, the |
+       Note  that  a  conditional  subpattern  is not considered as having two
+       alternatives, because only one is ever used.  In  other  words,  the  |
        character in a conditional subpattern has a different meaning. Ignoring
        white space, consider:
 
          ^.*? (?(?=a) a | b(*THEN)c )
 
-       If  the  subject  is  "ba", this pattern does not match. Because .*? is
-       ungreedy, it initially matches zero  characters.  The  condition  (?=a)
-       then  fails,  the  character  "b"  is  matched, but "c" is not. At this
-       point, matching does not backtrack to .*? as might perhaps be  expected
-       from  the  presence  of  the | character. The conditional subpattern is
+       If the subject is "ba", this pattern does not  match.  Because  .*?  is
+       ungreedy,  it  initially  matches  zero characters. The condition (?=a)
+       then fails, the character "b" is matched,  but  "c"  is  not.  At  this
+       point,  matching does not backtrack to .*? as might perhaps be expected
+       from the presence of the | character.  The  conditional  subpattern  is
        part of the single alternative that comprises the whole pattern, and so
-       the  match  fails.  (If  there was a backtrack into .*?, allowing it to
+       the match fails. (If there was a backtrack into  .*?,  allowing  it  to
        match "b", the match would succeed.)
 
-       The verbs just described provide four different "strengths" of  control
+       The  verbs just described provide four different "strengths" of control
        when subsequent matching fails. (*THEN) is the weakest, carrying on the
-       match at the next alternative. (*PRUNE) comes next, failing  the  match
-       at  the  current starting position, but allowing an advance to the next
-       character (for an unanchored pattern). (*SKIP) is similar, except  that
+       match  at  the next alternative. (*PRUNE) comes next, failing the match
+       at the current starting position, but allowing an advance to  the  next
+       character  (for an unanchored pattern). (*SKIP) is similar, except that
        the advance may be more than one character. (*COMMIT) is the strongest,
        causing the entire match to fail.
 
    More than one backtracking verb
 
-       If more than one backtracking verb is present in  a  pattern,  the  one
-       that  is  backtracked  onto first acts. For example, consider this pat-
+       If  more  than  one  backtracking verb is present in a pattern, the one
+       that is backtracked onto first acts. For example,  consider  this  pat-
        tern, where A, B, etc. are complex pattern fragments:
 
          (A(*COMMIT)B(*THEN)C|ABD)
 
-       If A matches but B fails, the backtrack to (*COMMIT) causes the  entire
+       If  A matches but B fails, the backtrack to (*COMMIT) causes the entire
        match to fail. However, if A and B match, but C fails, the backtrack to
-       (*THEN) causes the next alternative (ABD) to be tried.  This  behaviour
-       is  consistent,  but is not always the same as Perl's. It means that if
-       two or more backtracking verbs appear in succession, all the  the  last
+       (*THEN)  causes  the next alternative (ABD) to be tried. This behaviour
+       is consistent, but is not always the same as Perl's. It means  that  if
+       two  or  more backtracking verbs appear in succession, all the the last
        of them has no effect. Consider this example:
 
          ...(*COMMIT)(*PRUNE)...
 
        If there is a matching failure to the right, backtracking onto (*PRUNE)
-       causes it to be triggered, and its action is taken. There can never  be
+       causes  it to be triggered, and its action is taken. There can never be
        a backtrack onto (*COMMIT).
 
    Backtracking verbs in repeated groups
 
-       PCRE2  differs  from  Perl  in  its  handling  of backtracking verbs in
+       PCRE2 differs from Perl  in  its  handling  of  backtracking  verbs  in
        repeated groups. For example, consider:
 
          /(a(*COMMIT)b)+ac/
 
-       If the subject is "abac", Perl matches, but  PCRE2  fails  because  the
+       If  the  subject  is  "abac", Perl matches, but PCRE2 fails because the
        (*COMMIT) in the second repeat of the group acts.
 
    Backtracking verbs in assertions
 
-       (*FAIL)  in any assertion has its normal effect: it forces an immediate
-       backtrack. The behaviour of the other  backtracking  verbs  depends  on
-       whether  or  not the assertion is standalone or acting as the condition
+       (*FAIL) in any assertion has its normal effect: it forces an  immediate
+       backtrack.  The  behaviour  of  the other backtracking verbs depends on
+       whether or not the assertion is standalone or acting as  the  condition
        in a conditional subpattern.
 
-       (*ACCEPT) in a standalone positive assertion causes  the  assertion  to
-       succeed  without any further processing; captured strings are retained.
-       In a standalone negative assertion, (*ACCEPT) causes the  assertion  to
+       (*ACCEPT)  in  a  standalone positive assertion causes the assertion to
+       succeed without any further processing; captured strings are  retained.
+       In  a  standalone negative assertion, (*ACCEPT) causes the assertion to
        fail without any further processing; captured substrings are discarded.
 
-       If  the  assertion is a condition, (*ACCEPT) causes the condition to be
-       true for a positive assertion and false for a  negative  one;  captured
+       If the assertion is a condition, (*ACCEPT) causes the condition  to  be
+       true  for  a  positive assertion and false for a negative one; captured
        substrings are retained in both cases.
 
-       The  effect of (*THEN) is not allowed to escape beyond an assertion. If
-       there are no more branches to try, (*THEN) causes a positive  assertion
+       The effect of (*THEN) is not allowed to escape beyond an assertion.  If
+       there  are no more branches to try, (*THEN) causes a positive assertion
        to be false, and a negative assertion to be true.
 
-       The  other  backtracking verbs are not treated specially if they appear
-       in a standalone positive assertion. In a  conditional  positive  asser-
+       The other backtracking verbs are not treated specially if  they  appear
+       in  a  standalone  positive assertion. In a conditional positive asser-
        tion, backtracking into (*COMMIT), (*SKIP), or (*PRUNE) causes the con-
-       dition to be false. However, for both standalone and conditional  nega-
-       tive  assertions,  backtracking  into  (*COMMIT),  (*SKIP), or (*PRUNE)
+       dition  to be false. However, for both standalone and conditional nega-
+       tive assertions, backtracking  into  (*COMMIT),  (*SKIP),  or  (*PRUNE)
        causes the assertion to be true, without considering any further alter-
        native branches.
 
    Backtracking verbs in subroutines
 
-       These  behaviours  occur whether or not the subpattern is called recur-
+       These behaviours occur whether or not the subpattern is  called  recur-
        sively.  Perl's treatment of subroutines is different in some cases.
 
-       (*FAIL) in a subpattern called as a subroutine has its  normal  effect:
+       (*FAIL)  in  a subpattern called as a subroutine has its normal effect:
        it forces an immediate backtrack.
 
-       (*ACCEPT)  in a subpattern called as a subroutine causes the subroutine
-       match to succeed without any further processing. Matching then  contin-
+       (*ACCEPT) in a subpattern called as a subroutine causes the  subroutine
+       match  to succeed without any further processing. Matching then contin-
        ues after the subroutine call.
 
        (*COMMIT), (*SKIP), and (*PRUNE) in a subpattern called as a subroutine
        cause the subroutine match to fail.
 
-       (*THEN) skips to the next alternative in the innermost enclosing  group
-       within  the subpattern that has alternatives. If there is no such group
+       (*THEN)  skips to the next alternative in the innermost enclosing group
+       within the subpattern that has alternatives. If there is no such  group
        within the subpattern, (*THEN) causes the subroutine match to fail.
 
 
 SEE ALSO
 
-       pcre2api(3),   pcre2callout(3),    pcre2matching(3),    pcre2syntax(3),
+       pcre2api(3),    pcre2callout(3),    pcre2matching(3),   pcre2syntax(3),
        pcre2(3).
 
 
@@ -8590,7 +8598,7 @@ AUTHOR
 
 REVISION
 
-       Last updated: 11 April 2017
+       Last updated: 18 April 2017
        Copyright (c) 1997-2017 University of Cambridge.
 ------------------------------------------------------------------------------
  
@@ -9643,7 +9651,8 @@ OPTION SETTING
          (?m)            multiline
          (?s)            single line (dotall)
          (?U)            default ungreedy (lazy)
-         (?x)            extended (ignore white space)
+         (?x)            extended: ignore white space except in classes
+         (?xx)           as (?x) but also ignore space and tab in classes
          (?-...)         unset option(s)
 
        The following are recognized only at the very start  of  a  pattern  or
@@ -9807,7 +9816,7 @@ AUTHOR
 
 REVISION
 
-       Last updated: 31 March 2017
+       Last updated: 18 April 2017
        Copyright (c) 1997-2017 University of Cambridge.
 ------------------------------------------------------------------------------
  
diff --git a/doc/pcre2api.3 b/doc/pcre2api.3
index 8803c48..6006f04 100644
--- a/doc/pcre2api.3
+++ b/doc/pcre2api.3
@@ -1,4 +1,4 @@
-.TH PCRE2API 3 "14 April 2017" "PCRE2 10.30"
+.TH PCRE2API 3 "17 April 2017" "PCRE2 10.30"
 .SH NAME
 PCRE2 - Perl-compatible regular expressions (revised API)
 .sp
@@ -1347,6 +1347,13 @@ sequence at the start of the pattern, as described in the section entitled
 .\"
 in the \fBpcre2pattern\fP documentation. A default is defined when PCRE2 is
 built.
+.sp
+  PCRE2_EXTENDED_MORE
+.sp
+This option has the effect of PCRE2_EXTENDED, but, in addition, space and
+horizontal tab characters are also ignored inside a character class.
+PCRE2_EXTENDED_MORE is equivalent to Perl's 5.26 /xx option, and it can be
+changed within a pattern by a (?xx) option setting.
 .sp
   PCRE2_FIRSTLINE
 .sp
@@ -3395,6 +3402,6 @@ Cambridge, England.
 .rs
 .sp
 .nf
-Last updated: 14 April 2017
+Last updated: 17 April 2017
 Copyright (c) 1997-2017 University of Cambridge.
 .fi
diff --git a/doc/pcre2compat.3 b/doc/pcre2compat.3
index f6c1bb4..b3722df 100644
--- a/doc/pcre2compat.3
+++ b/doc/pcre2compat.3
@@ -1,4 +1,4 @@
-.TH PCRE2COMPAT 3 "17 April 2017" "PCRE2 10.30"
+.TH PCRE2COMPAT 3 "18 April 2017" "PCRE2 10.30"
 .SH NAME
 PCRE2 - Perl-compatible regular expressions (revised API)
 .SH "DIFFERENCES BETWEEN PCRE2 AND PERL"
@@ -165,13 +165,11 @@ different way and is not Perl-compatible.
 (l) PCRE2 recognizes some special sequences such as (*CR) or (*NO_JIT) at
 the start of a pattern that set overall options that cannot be changed within
 the pattern.
-.sp
-18. The following new Perl 5.26 constructs are not yet supported in PCRE2:
-.sp
-(a) The Perl /a modifier restricts /d numbers to pure ascii, the new /aa
-modifier restricts /i case-insensitive matching to pure ascii also, ignoring
-unicode rules. This separation cannot be represented with PCRE2_UTF.
-.sp
+.P
+18. The Perl /a modifier restricts /d numbers to pure ascii, and the /aa
+modifier restricts /i case-insensitive matching to pure ascii, ignoring Unicode
+rules. This separation cannot be represented with PCRE2_UCP.
+.P
 19. Perl has different limits than PCRE2. See the
 .\" HREF
 \fBpcre2limit\fP
@@ -196,6 +194,6 @@ Cambridge, England.
 .rs
 .sp
 .nf
-Last updated: 17 April 2017
+Last updated: 18 April 2017
 Copyright (c) 1997-2017 University of Cambridge.
 .fi
diff --git a/doc/pcre2pattern.3 b/doc/pcre2pattern.3
index 9a3257f..8978530 100644
--- a/doc/pcre2pattern.3
+++ b/doc/pcre2pattern.3
@@ -1,4 +1,4 @@
-.TH PCRE2PATTERN 3 "11 April 2017" "PCRE2 10.30"
+.TH PCRE2PATTERN 3 "18 April 2017" "PCRE2 10.30"
 .SH NAME
 PCRE2 - Perl-compatible regular expressions (revised API)
 .SH "PCRE2 REGULAR EXPRESSION DETAILS"
@@ -1542,20 +1542,24 @@ alternative in the subpattern.
 .SH "INTERNAL OPTION SETTING"
 .rs
 .sp
-The settings of the PCRE2_CASELESS, PCRE2_MULTILINE, PCRE2_DOTALL, and
-PCRE2_EXTENDED options (which are Perl-compatible) can be changed from within
-the pattern by a sequence of Perl option letters enclosed between "(?" and ")".
-The option letters are
+The settings of the PCRE2_CASELESS, PCRE2_MULTILINE, PCRE2_DOTALL,
+PCRE2_EXTENDED, and PCRE2_EXTENDED_MORE options (which are Perl-compatible) can
+be changed from within the pattern by a sequence of Perl option letters
+enclosed between "(?" and ")". The option letters are
 .sp
   i  for PCRE2_CASELESS
   m  for PCRE2_MULTILINE
   s  for PCRE2_DOTALL
   x  for PCRE2_EXTENDED
+  xx for PCRE2_EXTENDED_MORE
 .sp
 For example, (?im) sets caseless, multiline matching. It is also possible to
-unset these options by preceding the letter with a hyphen, and a combined
-setting and unsetting such as (?im-sx), which sets PCRE2_CASELESS and
-PCRE2_MULTILINE while unsetting PCRE2_DOTALL and PCRE2_EXTENDED, is also
+unset these options by preceding the letter with a hyphen. The two "extended" 
+options are not independent; unsetting either one cancels the effects of both 
+of them. 
+.P
+A combined setting and unsetting such as (?im-sx), which sets PCRE2_CASELESS
+and PCRE2_MULTILINE while unsetting PCRE2_DOTALL and PCRE2_EXTENDED, is also
 permitted. If a letter appears both before and after the hyphen, the option is
 unset. An empty options setting "(?)" is allowed. Needless to say, it has no
 effect.
@@ -3469,6 +3473,6 @@ Cambridge, England.
 .rs
 .sp
 .nf
-Last updated: 11 April 2017
+Last updated: 18 April 2017
 Copyright (c) 1997-2017 University of Cambridge.
 .fi
diff --git a/doc/pcre2syntax.3 b/doc/pcre2syntax.3
index 05b129c..7901102 100644
--- a/doc/pcre2syntax.3
+++ b/doc/pcre2syntax.3
@@ -1,4 +1,4 @@
-.TH PCRE2SYNTAX 3 "31 March 2017" "PCRE2 10.30"
+.TH PCRE2SYNTAX 3 "18 April 2017" "PCRE2 10.30"
 .SH NAME
 PCRE2 - Perl-compatible regular expressions (revised API)
 .SH "PCRE2 REGULAR EXPRESSION SYNTAX SUMMARY"
@@ -409,7 +409,8 @@ but some of them use Unicode properties if PCRE2_UCP is set. You can use
   (?m)            multiline
   (?s)            single line (dotall)
   (?U)            default ungreedy (lazy)
-  (?x)            extended (ignore white space)
+  (?x)            extended: ignore white space except in classes
+  (?xx)           as (?x) but also ignore space and tab in classes 
   (?-...)         unset option(s)
 .sp
 The following are recognized only at the very start of a pattern or after one
@@ -585,6 +586,6 @@ Cambridge, England.
 .rs
 .sp
 .nf
-Last updated: 31 March 2017
+Last updated: 18 April 2017
 Copyright (c) 1997-2017 University of Cambridge.
 .fi
diff --git a/doc/pcre2test.1 b/doc/pcre2test.1
index 9653241..d177cc4 100644
--- a/doc/pcre2test.1
+++ b/doc/pcre2test.1
@@ -1,4 +1,4 @@
-.TH PCRE2TEST 1 "11 April 2017" "PCRE 10.30"
+.TH PCRE2TEST 1 "17 April 2017" "PCRE 10.30"
 .SH NAME
 pcre2test - a program for testing Perl-compatible regular expressions.
 .SH SYNOPSIS
@@ -520,11 +520,13 @@ by a previous \fB#pattern\fP command.
 .rs
 .sp
 The following modifiers set options for \fBpcre2_compile()\fP. The most common
-ones have single-letter abbreviations. See
+ones have single-letter abbreviations, with special handling for /x (to make
+it like Perl). If a second x is present, PCRE2_EXTENDED is converted into
+PCRE2_EXTENDED_MORE. A third appearance adds PCRE2_EXTENDED as well. See
 .\" HREF
 \fBpcre2api\fP
 .\"
-for a description of their effects.
+for a description of the effects of these options.
 .sp
       allow_empty_class         set PCRE2_ALLOW_EMPTY_CLASS
       alt_bsux                  set PCRE2_ALT_BSUX
@@ -538,6 +540,7 @@ for a description of their effects.
       dupnames                  set PCRE2_DUPNAMES
       endanchored               set PCRE2_ENDANCHORED
   /x  extended                  set PCRE2_EXTENDED
+  /xx extended_more             set PCRE2_EXTENDED_MORE 
       firstline                 set PCRE2_FIRSTLINE
       match_unset_backref       set PCRE2_MATCH_UNSET_BACKREF
   /m  multiline                 set PCRE2_MULTILINE
@@ -1783,6 +1786,6 @@ Cambridge, England.
 .rs
 .sp
 .nf
-Last updated: 11 April 2017
+Last updated: 17 April 2017
 Copyright (c) 1997-2017 University of Cambridge.
 .fi
diff --git a/doc/pcre2test.txt b/doc/pcre2test.txt
index c311d83..7313c69 100644
--- a/doc/pcre2test.txt
+++ b/doc/pcre2test.txt
@@ -504,8 +504,11 @@ PATTERN MODIFIERS
    Setting compilation options
 
        The  following modifiers set options for pcre2_compile(). The most com-
-       mon ones have single-letter abbreviations. See pcre2api for a  descrip-
-       tion of their effects.
+       mon ones have single-letter abbreviations, with special handling for /x
+       (to  make  it  like  Perl). If a second x is present, PCRE2_EXTENDED is
+       converted   into   PCRE2_EXTENDED_MORE.   A   third   appearance   adds
+       PCRE2_EXTENDED  as  well. See pcre2api for a description of the effects
+       of these options.
 
              allow_empty_class         set PCRE2_ALLOW_EMPTY_CLASS
              alt_bsux                  set PCRE2_ALT_BSUX
@@ -519,6 +522,7 @@ PATTERN MODIFIERS
              dupnames                  set PCRE2_DUPNAMES
              endanchored               set PCRE2_ENDANCHORED
          /x  extended                  set PCRE2_EXTENDED
+         /xx extended_more             set PCRE2_EXTENDED_MORE
              firstline                 set PCRE2_FIRSTLINE
              match_unset_backref       set PCRE2_MATCH_UNSET_BACKREF
          /m  multiline                 set PCRE2_MULTILINE
@@ -536,15 +540,15 @@ PATTERN MODIFIERS
              utf                       set PCRE2_UTF
 
        As well as turning on the PCRE2_UTF option, the utf modifier causes all
-       non-printing characters in output  strings  to  be  printed  using  the
-       \x{hh...}  notation. Otherwise, those less than 0x100 are output in hex
-       without the curly brackets. Setting utf in 16-bit or 32-bit  mode  also
-       causes  pattern  and  subject  strings  to  be  translated to UTF-16 or
+       non-printing  characters  in  output  strings  to  be printed using the
+       \x{hh...} notation. Otherwise, those less than 0x100 are output in  hex
+       without  the  curly brackets. Setting utf in 16-bit or 32-bit mode also
+       causes pattern and subject  strings  to  be  translated  to  UTF-16  or
        UTF-32, respectively, before being passed to library functions.
 
    Setting compilation controls
 
-       The following modifiers  affect  the  compilation  process  or  request
+       The  following  modifiers  affect  the  compilation  process or request
        information about the pattern:
 
              bsr=[anycrlf|unicode]     specify \R handling
@@ -577,34 +581,34 @@ PATTERN MODIFIERS
 
    Newline and \R handling
 
-       The  bsr modifier specifies what \R in a pattern should match. If it is
-       set to "anycrlf", \R matches CR, LF, or CRLF only.  If  it  is  set  to
-       "unicode",  \R  matches  any  Unicode  newline sequence. The default is
+       The bsr modifier specifies what \R in a pattern should match. If it  is
+       set  to  "anycrlf",  \R  matches  CR, LF, or CRLF only. If it is set to
+       "unicode", \R matches any Unicode  newline  sequence.  The  default  is
        specified when PCRE2 is built, with the default default being Unicode.
 
-       The newline modifier specifies which characters are to  be  interpreted
+       The  newline  modifier specifies which characters are to be interpreted
        as newlines, both in the pattern and in subject lines. The type must be
        one of CR, LF, CRLF, ANYCRLF, or ANY (in upper or lower case).
 
    Information about a pattern
 
-       The debug modifier is a shorthand for info,fullbincode, requesting  all
+       The  debug modifier is a shorthand for info,fullbincode, requesting all
        available information.
 
        The bincode modifier causes a representation of the compiled code to be
-       output after compilation. This information does not contain length  and
+       output  after compilation. This information does not contain length and
        offset values, which ensures that the same output is generated for dif-
-       ferent internal link sizes and different code  unit  widths.  By  using
-       bincode,  the  same  regression tests can be used in different environ-
+       ferent  internal  link  sizes  and different code unit widths. By using
+       bincode, the same regression tests can be used  in  different  environ-
        ments.
 
-       The fullbincode modifier, by contrast, does include length  and  offset
-       values.  This is used in a few special tests that run only for specific
+       The  fullbincode  modifier, by contrast, does include length and offset
+       values. This is used in a few special tests that run only for  specific
        code unit widths and link sizes, and is also useful for one-off tests.
 
-       The info modifier  requests  information  about  the  compiled  pattern
-       (whether  it  is anchored, has a fixed first character, and so on). The
-       information is obtained from the  pcre2_pattern_info()  function.  Here
+       The  info  modifier  requests  information  about  the compiled pattern
+       (whether it is anchored, has a fixed first character, and so  on).  The
+       information  is  obtained  from the pcre2_pattern_info() function. Here
        are some typical examples:
 
            re> /(?i)(^a|^b)/m,info
@@ -622,118 +626,118 @@ PATTERN MODIFIERS
          Last code unit = 'c' (caseless)
          Subject length lower bound = 3
 
-       "Compile  options"  are those specified by modifiers; "overall options"
-       have added options that are taken or deduced from the pattern. If  both
-       sets  of  options are the same, just a single "options" line is output;
-       if there are no options, the line is  omitted.  "First  code  unit"  is
-       where  any  match must start; if there is more than one they are listed
-       as "starting code units". "Last code unit" is  the  last  literal  code
-       unit  that  must  be  present in any match. This is not necessarily the
-       last character. These lines are omitted if no starting or  ending  code
+       "Compile options" are those specified by modifiers;  "overall  options"
+       have  added options that are taken or deduced from the pattern. If both
+       sets of options are the same, just a single "options" line  is  output;
+       if  there  are  no  options,  the line is omitted. "First code unit" is
+       where any match must start; if there is more than one they  are  listed
+       as  "starting  code  units".  "Last code unit" is the last literal code
+       unit that must be present in any match. This  is  not  necessarily  the
+       last  character.  These lines are omitted if no starting or ending code
        units are recorded.
 
-       The  framesize modifier shows the size, in bytes, of the storage frames
-       used by pcre2_match() for handling backtracking. The  size  depends  on
+       The framesize modifier shows the size, in bytes, of the storage  frames
+       used  by  pcre2_match()  for handling backtracking. The size depends on
        the number of capturing parentheses in the pattern.
 
-       The  callout_info  modifier requests information about all the callouts
+       The callout_info modifier requests information about all  the  callouts
        in the pattern. A list of them is output at the end of any other infor-
        mation that is requested. For each callout, either its number or string
        is given, followed by the item that follows it in the pattern.
 
    Passing a NULL context
 
-       Normally, pcre2test passes a context block to pcre2_compile().  If  the
-       null_context  modifier  is  set,  however,  NULL is passed. This is for
-       testing that pcre2_compile() behaves correctly in this  case  (it  uses
+       Normally,  pcre2test  passes a context block to pcre2_compile(). If the
+       null_context modifier is set, however, NULL  is  passed.  This  is  for
+       testing  that  pcre2_compile()  behaves correctly in this case (it uses
        default values).
 
    Specifying the pattern's length
 
        By default, patterns are passed to the compiling functions as zero-ter-
-       minated strings. When using the POSIX wrapper API, there  is  no  other
-       option.  However, when using PCRE2's native API, patterns can be passed
-       by length instead of being  zero-terminated.  The  use_length  modifier
-       causes  this  to happen.  Using a length happens automatically (whether
-       or not use_length is set) when hex is set, because  patterns  specified
+       minated  strings.  When  using the POSIX wrapper API, there is no other
+       option. However, when using PCRE2's native API, patterns can be  passed
+       by  length  instead  of  being zero-terminated. The use_length modifier
+       causes this to happen.  Using a length happens  automatically  (whether
+       or  not  use_length is set) when hex is set, because patterns specified
        in hexadecimal may contain binary zeros.
 
    Specifying pattern characters in hexadecimal
 
-       The  hex  modifier specifies that the characters of the pattern, except
-       for substrings enclosed in single or double quotes, are  to  be  inter-
-       preted  as  pairs  of hexadecimal digits. This feature is provided as a
+       The hex modifier specifies that the characters of the  pattern,  except
+       for  substrings  enclosed  in single or double quotes, are to be inter-
+       preted as pairs of hexadecimal digits. This feature is  provided  as  a
        way of creating patterns that contain binary zeros and other non-print-
-       ing  characters.  White space is permitted between pairs of digits. For
+       ing characters. White space is permitted between pairs of  digits.  For
        example, this pattern contains three characters:
 
          /ab 32 59/hex
 
-       Parts of such a pattern are taken literally  if  quoted.  This  pattern
-       contains  nine characters, only two of which are specified in hexadeci-
+       Parts  of  such  a  pattern are taken literally if quoted. This pattern
+       contains nine characters, only two of which are specified in  hexadeci-
        mal:
 
          /ab "literal" 32/hex
 
-       Either single or double quotes may be used. There is no way of  includ-
-       ing  the delimiter within a substring. The hex and expand modifiers are
+       Either  single or double quotes may be used. There is no way of includ-
+       ing the delimiter within a substring. The hex and expand modifiers  are
        mutually exclusive.
 
-       The POSIX API cannot be used with  patterns  specified  in  hexadecimal
+       The  POSIX  API  cannot  be used with patterns specified in hexadecimal
        because they may contain binary zeros, which conflicts with regcomp()'s
-       requirement for a zero-terminated  string.  Such  patterns  are  always
+       requirement  for  a  zero-terminated  string.  Such patterns are always
        passed to pcre2_compile() as a string with a length, not as zero-termi-
        nated.
 
    Specifying wide characters in 16-bit and 32-bit modes
 
        In 16-bit and 32-bit modes, all input is automatically treated as UTF-8
-       and  translated  to  UTF-16 or UTF-32 when the utf modifier is set. For
+       and translated to UTF-16 or UTF-32 when the utf modifier  is  set.  For
        testing the 16-bit and 32-bit libraries in non-UTF mode, the utf8_input
-       modifier  can  be  used. It is mutually exclusive with utf. Input lines
+       modifier can be used. It is mutually exclusive with  utf.  Input  lines
        are interpreted as UTF-8 as a means of specifying wide characters. More
        details are given in "Input encoding" above.
 
    Generating long repetitive patterns
 
-       Some  tests use long patterns that are very repetitive. Instead of cre-
-       ating a very long input line for such a pattern, you can use a  special
-       repetition  feature,  similar  to  the  one described for subject lines
-       above. If the expand modifier is present on a  pattern,  parts  of  the
+       Some tests use long patterns that are very repetitive. Instead of  cre-
+       ating  a very long input line for such a pattern, you can use a special
+       repetition feature, similar to the  one  described  for  subject  lines
+       above.  If  the  expand  modifier is present on a pattern, parts of the
        pattern that have the form
 
          \[]{}
 
        are expanded before the pattern is passed to pcre2_compile(). For exam-
        ple, \[AB]{6000} is expanded to "ABAB..." 6000 times. This construction
-       cannot  be  nested. An initial "\[" sequence is recognized only if "]{"
-       followed by decimal digits and "}" is found later in  the  pattern.  If
+       cannot be nested. An initial "\[" sequence is recognized only  if  "]{"
+       followed  by  decimal  digits and "}" is found later in the pattern. If
        not, the characters remain in the pattern unaltered. The expand and hex
        modifiers are mutually exclusive.
 
-       If part of an expanded pattern looks like an expansion, but  is  really
+       If  part  of an expanded pattern looks like an expansion, but is really
        part of the actual pattern, unwanted expansion can be avoided by giving
        two values in the quantifier. For example, \[AB]{6000,6000} is not rec-
        ognized as an expansion item.
 
-       If  the  info modifier is set on an expanded pattern, the result of the
+       If the info modifier is set on an expanded pattern, the result  of  the
        expansion is included in the information that is output.
 
    JIT compilation
 
-       Just-in-time (JIT) compiling is a  heavyweight  optimization  that  can
-       greatly  speed  up pattern matching. See the pcre2jit documentation for
-       details. JIT compiling happens, optionally, after a  pattern  has  been
-       successfully  compiled into an internal form. The JIT compiler converts
+       Just-in-time  (JIT)  compiling  is  a heavyweight optimization that can
+       greatly speed up pattern matching. See the pcre2jit  documentation  for
+       details.  JIT  compiling  happens, optionally, after a pattern has been
+       successfully compiled into an internal form. The JIT compiler  converts
        this to optimized machine code. It needs to know whether the match-time
        options PCRE2_PARTIAL_HARD and PCRE2_PARTIAL_SOFT are going to be used,
-       because different code is generated for the different  cases.  See  the
-       partial  modifier in "Subject Modifiers" below for details of how these
+       because  different  code  is generated for the different cases. See the
+       partial modifier in "Subject Modifiers" below for details of how  these
        options are specified for each match attempt.
 
-       JIT compilation is requested by the /jit pattern  modifier,  which  may
+       JIT  compilation  is  requested by the /jit pattern modifier, which may
        optionally be followed by an equals sign and a number in the range 0 to
-       7.  The three bits that make up the number specify which of  the  three
+       7.   The  three bits that make up the number specify which of the three
        JIT operating modes are to be compiled:
 
          1  compile JIT code for non-partial matching
@@ -750,31 +754,31 @@ PATTERN MODIFIERS
          6  soft and hard partial matching only
          7  all three modes
 
-       If  no  number  is  given,  7 is assumed. The phrase "partial matching"
+       If no number is given, 7 is  assumed.  The  phrase  "partial  matching"
        means a call to pcre2_match() with either the PCRE2_PARTIAL_SOFT or the
-       PCRE2_PARTIAL_HARD  option set. Note that such a call may return a com-
+       PCRE2_PARTIAL_HARD option set. Note that such a call may return a  com-
        plete match; the options enable the possibility of a partial match, but
-       do  not  require it. Note also that if you request JIT compilation only
-       for partial matching (for example, /jit=2) but do not set  the  partial
-       modifier  on  a  subject line, that match will not use JIT code because
+       do not require it. Note also that if you request JIT  compilation  only
+       for  partial  matching (for example, /jit=2) but do not set the partial
+       modifier on a subject line, that match will not use  JIT  code  because
        none was compiled for non-partial matching.
 
-       If JIT compilation is successful, the compiled JIT code will  automati-
-       cally  be  used  when  an appropriate type of match is run, except when
-       incompatible run-time options are specified. For more details, see  the
-       pcre2jit  documentation. See also the jitstack modifier below for a way
+       If  JIT compilation is successful, the compiled JIT code will automati-
+       cally be used when an appropriate type of match  is  run,  except  when
+       incompatible  run-time options are specified. For more details, see the
+       pcre2jit documentation. See also the jitstack modifier below for a  way
        of setting the size of the JIT stack.
 
-       If the jitfast modifier is specified, matching is done  using  the  JIT
-       "fast  path" interface, pcre2_jit_match(), which skips some of the san-
-       ity checks that are done by pcre2_match(), and of course does not  work
-       when  JIT  is not supported. If jitfast is specified without jit, jit=7
+       If  the  jitfast  modifier is specified, matching is done using the JIT
+       "fast path" interface, pcre2_jit_match(), which skips some of the  san-
+       ity  checks that are done by pcre2_match(), and of course does not work
+       when JIT is not supported. If jitfast is specified without  jit,  jit=7
        is assumed.
 
-       If the jitverify modifier is specified, information about the  compiled
-       pattern  shows  whether  JIT  compilation was or was not successful. If
-       jitverify is specified without jit, jit=7 is assumed. If  JIT  compila-
-       tion  is successful when jitverify is set, the text "(JIT)" is added to
+       If  the jitverify modifier is specified, information about the compiled
+       pattern shows whether JIT compilation was or  was  not  successful.  If
+       jitverify  is  specified without jit, jit=7 is assumed. If JIT compila-
+       tion is successful when jitverify is set, the text "(JIT)" is added  to
        the first output line after a match or non match when JIT-compiled code
        was actually used in the match.
 
@@ -785,19 +789,19 @@ PATTERN MODIFIERS
          /pattern/locale=fr_FR
 
        The given locale is set, pcre2_maketables() is called to build a set of
-       character tables for the locale, and this is then passed to  pcre2_com-
-       pile()  when compiling the regular expression. The same tables are used
-       when matching the following subject lines. The locale modifier  applies
+       character  tables for the locale, and this is then passed to pcre2_com-
+       pile() when compiling the regular expression. The same tables are  used
+       when  matching the following subject lines. The locale modifier applies
        only to the pattern on which it appears, but can be given in a #pattern
-       command if a default is needed. Setting a locale and alternate  charac-
+       command  if a default is needed. Setting a locale and alternate charac-
        ter tables are mutually exclusive.
 
    Showing pattern memory
 
        The memory modifier causes the size in bytes of the memory used to hold
-       the compiled pattern to be output. This does not include  the  size  of
-       the  pcre2_code block; it is just the actual compiled data. If the pat-
-       tern is subsequently passed to the JIT compiler, the size  of  the  JIT
+       the  compiled  pattern  to be output. This does not include the size of
+       the pcre2_code block; it is just the actual compiled data. If the  pat-
+       tern  is  subsequently  passed to the JIT compiler, the size of the JIT
        compiled code is also output. Here is an example:
 
            re> /a(b)c/jit,memory
@@ -807,27 +811,27 @@ PATTERN MODIFIERS
 
    Limiting nested parentheses
 
-       The  parens_nest_limit  modifier  sets  a  limit on the depth of nested
-       parentheses in a pattern. Breaching  the  limit  causes  a  compilation
-       error.   The  default  for  the library is set when PCRE2 is built, but
-       pcre2test sets its own default of 220, which is  required  for  running
+       The parens_nest_limit modifier sets a limit  on  the  depth  of  nested
+       parentheses  in  a  pattern.  Breaching  the limit causes a compilation
+       error.  The default for the library is set when  PCRE2  is  built,  but
+       pcre2test  sets  its  own default of 220, which is required for running
        the standard test suite.
 
    Limiting the pattern length
 
-       The  max_pattern_length  modifier  sets  a limit, in code units, to the
+       The max_pattern_length modifier sets a limit, in  code  units,  to  the
        length of pattern that pcre2_compile() will accept. Breaching the limit
-       causes  a  compilation  error.  The  default  is  the  largest number a
+       causes a compilation  error.  The  default  is  the  largest  number  a
        PCRE2_SIZE variable can hold (essentially unlimited).
 
    Using the POSIX wrapper API
 
-       The /posix and posix_nosub modifiers cause pcre2test to call PCRE2  via
-       the  POSIX  wrapper API rather than its native API. When posix_nosub is
-       used, the POSIX option REG_NOSUB is  passed  to  regcomp().  The  POSIX
-       wrapper  supports  only  the 8-bit library. Note that it does not imply
+       The  /posix and posix_nosub modifiers cause pcre2test to call PCRE2 via
+       the POSIX wrapper API rather than its native API. When  posix_nosub  is
+       used,  the  POSIX  option  REG_NOSUB  is passed to regcomp(). The POSIX
+       wrapper supports only the 8-bit library. Note that it  does  not  imply
        POSIX matching semantics; for more detail see the pcre2posix documenta-
-       tion.  The  following  pattern  modifiers set options for the regcomp()
+       tion. The following pattern modifiers set  options  for  the  regcomp()
        function:
 
          caseless           REG_ICASE
@@ -837,35 +841,35 @@ PATTERN MODIFIERS
          ucp                REG_UCP        )   the POSIX standard
          utf                REG_UTF8       )
 
-       The regerror_buffsize modifier specifies a size for  the  error  buffer
-       that  is  passed to regerror() in the event of a compilation error. For
+       The  regerror_buffsize  modifier  specifies a size for the error buffer
+       that is passed to regerror() in the event of a compilation  error.  For
        example:
 
          /abc/posix,regerror_buffsize=20
 
-       This provides a means of testing the behaviour of regerror()  when  the
-       buffer  is  too  small  for the error message. If this modifier has not
+       This  provides  a means of testing the behaviour of regerror() when the
+       buffer is too small for the error message. If  this  modifier  has  not
        been set, a large buffer is used.
 
-       The aftertext and allaftertext  subject  modifiers  work  as  described
-       below.  All other modifiers are either ignored, with a warning message,
+       The  aftertext  and  allaftertext  subject  modifiers work as described
+       below. All other modifiers are either ignored, with a warning  message,
        or cause an error.
 
    Testing the stack guard feature
 
-       The stackguard modifier is used  to  test  the  use  of  pcre2_set_com-
-       pile_recursion_guard(),  a  function  that  is provided to enable stack
-       availability to be checked during compilation (see the  pcre2api  docu-
-       mentation  for  details).  If  the  number specified by the modifier is
+       The  stackguard  modifier  is  used  to  test the use of pcre2_set_com-
+       pile_recursion_guard(), a function that is  provided  to  enable  stack
+       availability  to  be checked during compilation (see the pcre2api docu-
+       mentation for details). If the number  specified  by  the  modifier  is
        greater than zero, pcre2_set_compile_recursion_guard() is called to set
-       up  callback  from pcre2_compile() to a local function. The argument it
-       receives is the current nesting parenthesis depth; if this  is  greater
+       up callback from pcre2_compile() to a local function. The  argument  it
+       receives  is  the current nesting parenthesis depth; if this is greater
        than the value given by the modifier, non-zero is returned, causing the
        compilation to be aborted.
 
    Using alternative character tables
 
-       The value specified for the tables modifier must be one of  the  digits
+       The  value  specified for the tables modifier must be one of the digits
        0, 1, or 2. It causes a specific set of built-in character tables to be
        passed to pcre2_compile(). This is used in the PCRE2 tests to check be-
        haviour with different character tables. The digit specifies the tables
@@ -876,15 +880,15 @@ PATTERN MODIFIERS
                pcre2_chartables.c.dist
          2   a set of tables defining ISO 8859 characters
 
-       In table 2, some characters whose codes are greater than 128 are  iden-
-       tified  as  letters,  digits,  spaces, etc. Setting alternate character
+       In  table 2, some characters whose codes are greater than 128 are iden-
+       tified as letters, digits, spaces,  etc.  Setting  alternate  character
        tables and a locale are mutually exclusive.
 
    Setting certain match controls
 
        The following modifiers are really subject modifiers, and are described
-       below.   However, they may be included in a pattern's modifier list, in
-       which case they are applied to every subject  line  that  is  processed
+       below.  However, they may be included in a pattern's modifier list,  in
+       which  case  they  are  applied to every subject line that is processed
        with that pattern. They may not appear in #pattern commands. These mod-
        ifiers do not affect the compilation process.
 
@@ -901,24 +905,24 @@ PATTERN MODIFIERS
              substitute_unknown_unset   use PCRE2_SUBSTITUTE_UNKNOWN_UNSET
              substitute_unset_empty     use PCRE2_SUBSTITUTE_UNSET_EMPTY
 
-       These modifiers may not appear in a #pattern command. If you want  them
+       These  modifiers may not appear in a #pattern command. If you want them
        as defaults, set them in a #subject command.
 
    Saving a compiled pattern
 
-       When  a  pattern with the push modifier is successfully compiled, it is
-       pushed onto a stack of compiled patterns,  and  pcre2test  expects  the
-       next  line to contain a new pattern (or a command) instead of a subject
+       When a pattern with the push modifier is successfully compiled,  it  is
+       pushed  onto  a  stack  of compiled patterns, and pcre2test expects the
+       next line to contain a new pattern (or a command) instead of a  subject
        line. This facility is used when saving compiled patterns to a file, as
-       described  in  the section entitled "Saving and restoring compiled pat-
-       terns" below. If pushcopy is used instead of push, a copy of  the  com-
-       piled  pattern  is  stacked,  leaving the original as current, ready to
-       match the following input lines. This provides a  way  of  testing  the
-       pcre2_code_copy()  function.   The  push  and  pushcopy   modifiers are
-       incompatible with compilation modifiers such  as  global  that  act  at
-       match  time. Any that are specified are ignored (for the stacked copy),
+       described in the section entitled "Saving and restoring  compiled  pat-
+       terns"  below.  If pushcopy is used instead of push, a copy of the com-
+       piled pattern is stacked, leaving the original  as  current,  ready  to
+       match  the  following  input  lines. This provides a way of testing the
+       pcre2_code_copy() function.   The  push  and  pushcopy   modifiers  are
+       incompatible  with  compilation  modifiers  such  as global that act at
+       match time. Any that are specified are ignored (for the stacked  copy),
        with a warning message, except for replace, which causes an error. Note
-       that  jitverify, which is allowed, does not carry through to any subse-
+       that jitverify, which is allowed, does not carry through to any  subse-
        quent matching that uses a stacked pattern.
 
 
@@ -929,7 +933,7 @@ SUBJECT MODIFIERS
 
    Setting match options
 
-       The    following   modifiers   set   options   for   pcre2_match()   or
+       The   following   modifiers   set   options   for   pcre2_match()    or
        pcre2_dfa_match(). See pcreapi for a description of their effects.
 
              anchored                  set PCRE2_ANCHORED
@@ -945,20 +949,20 @@ SUBJECT MODIFIERS
              partial_hard (or ph)      set PCRE2_PARTIAL_HARD
              partial_soft (or ps)      set PCRE2_PARTIAL_SOFT
 
-       The partial matching modifiers are provided with abbreviations  because
+       The  partial matching modifiers are provided with abbreviations because
        they appear frequently in tests.
 
-       If  the  posix  modifier  was present on the pattern, causing the POSIX
+       If the posix modifier was present on the  pattern,  causing  the  POSIX
        wrapper API to be used, the only option-setting modifiers that have any
-       effect   are   notbol,   notempty,   and  noteol,  causing  REG_NOTBOL,
-       REG_NOTEMPTY, and REG_NOTEOL, respectively, to be passed to  regexec().
+       effect  are  notbol,  notempty,   and   noteol,   causing   REG_NOTBOL,
+       REG_NOTEMPTY,  and REG_NOTEOL, respectively, to be passed to regexec().
        The other modifiers are ignored, with a warning message.
 
    Setting match controls
 
-       The  following  modifiers  affect the matching process or request addi-
-       tional information. Some of them may also be  specified  on  a  pattern
-       line  (see  above), in which case they apply to every subject line that
+       The following modifiers affect the matching process  or  request  addi-
+       tional  information.  Some  of  them may also be specified on a pattern
+       line (see above), in which case they apply to every subject  line  that
        is matched against that pattern.
 
              aftertext                  show text after match
@@ -998,29 +1002,29 @@ SUBJECT MODIFIERS
              zero_terminate             pass the subject as zero-terminated
 
        The effects of these modifiers are described in the following sections.
-       When  matching  via the POSIX wrapper API, the aftertext, allaftertext,
-       and ovector subject modifiers work as described below. All other  modi-
+       When matching via the POSIX wrapper API, the  aftertext,  allaftertext,
+       and  ovector subject modifiers work as described below. All other modi-
        fiers are either ignored, with a warning message, or cause an error.
 
    Showing more text
 
-       The  aftertext modifier requests that as well as outputting the part of
+       The aftertext modifier requests that as well as outputting the part  of
        the subject string that matched the entire pattern, pcre2test should in
        addition output the remainder of the subject string. This is useful for
        tests where the subject contains multiple copies of the same substring.
-       The  allaftertext  modifier  requests the same action for captured sub-
+       The allaftertext modifier requests the same action  for  captured  sub-
        strings as well as the main matched substring. In each case the remain-
        der is output on the following line with a plus character following the
        capture number.
 
-       The allusedtext modifier requests that all the text that was  consulted
-       during  a  successful pattern match by the interpreter should be shown.
-       This feature is not supported for JIT matching, and if  requested  with
-       JIT  it  is  ignored  (with  a  warning message). Setting this modifier
+       The  allusedtext modifier requests that all the text that was consulted
+       during a successful pattern match by the interpreter should  be  shown.
+       This  feature  is not supported for JIT matching, and if requested with
+       JIT it is ignored (with  a  warning  message).  Setting  this  modifier
        affects the output if there is a lookbehind at the start of a match, or
-       a  lookahead  at  the  end, or if \K is used in the pattern. Characters
-       that precede or follow the start and end of the actual match are  indi-
-       cated  in  the output by '<' or '>' characters underneath them. Here is
+       a lookahead at the end, or if \K is used  in  the  pattern.  Characters
+       that  precede or follow the start and end of the actual match are indi-
+       cated in the output by '<' or '>' characters underneath them.  Here  is
        an example:
 
            re> /(?<=pqr)abc(?=xyz)/
@@ -1028,16 +1032,16 @@ SUBJECT MODIFIERS
           0: pqrabcxyz
              <<<   >>>
 
-       This shows that the matched string is "abc",  with  the  preceding  and
-       following  strings  "pqr"  and  "xyz"  having been consulted during the
+       This  shows  that  the  matched string is "abc", with the preceding and
+       following strings "pqr" and "xyz"  having  been  consulted  during  the
        match (when processing the assertions).
 
-       The startchar modifier requests that the  starting  character  for  the
-       match  be  indicated,  if  it  is different to the start of the matched
+       The  startchar  modifier  requests  that the starting character for the
+       match be indicated, if it is different to  the  start  of  the  matched
        string. The only time when this occurs is when \K has been processed as
        part of the match. In this situation, the output for the matched string
-       is displayed from the starting character  instead  of  from  the  match
-       point,  with  circumflex  characters  under the earlier characters. For
+       is  displayed  from  the  starting  character instead of from the match
+       point, with circumflex characters under  the  earlier  characters.  For
        example:
 
            re> /abc\Kxyz/
@@ -1045,7 +1049,7 @@ SUBJECT MODIFIERS
           0: abcxyz
              ^^^
 
-       Unlike allusedtext, the startchar modifier can be used with JIT.   How-
+       Unlike  allusedtext, the startchar modifier can be used with JIT.  How-
        ever, these two modifiers are mutually exclusive.
 
    Showing the value of all capture groups
@@ -1053,98 +1057,98 @@ SUBJECT MODIFIERS
        The allcaptures modifier requests that the values of all potential cap-
        tured parentheses be output after a match. By default, only those up to
        the highest one actually used in the match are output (corresponding to
-       the return code from pcre2_match()). Groups that did not take  part  in
-       the  match  are  output as "". This modifier is not relevant for
-       DFA matching (which does no capturing); it is ignored, with  a  warning
+       the  return  code from pcre2_match()). Groups that did not take part in
+       the match are output as "". This modifier is  not  relevant  for
+       DFA  matching  (which does no capturing); it is ignored, with a warning
        message, if present.
 
    Testing callouts
 
-       A  callout function is supplied when pcre2test calls the library match-
-       ing functions, unless callout_none is specified. If callout_capture  is
-       set,  the current captured groups are output when a callout occurs. The
+       A callout function is supplied when pcre2test calls the library  match-
+       ing  functions, unless callout_none is specified. If callout_capture is
+       set, the current captured groups are output when a callout occurs.  The
        default return from the callout function is zero, which allows matching
        to continue.
 
-       The  callout_fail modifier can be given one or two numbers. If there is
-       only one number, 1 is returned instead of 0 (causing matching to  back-
-       track)  when  a  callout  of  that  number  is  reached. If two numbers
-       (:) are given, 1 is returned when  callout    is  reached  and
-       there  have  been  at least  callouts. The callout_error modifier is
-       similar, except  that  PCRE2_ERROR_CALLOUT  is  returned,  causing  the
-       entire  matching process to be aborted. If both these modifiers are set
+       The callout_fail modifier can be given one or two numbers. If there  is
+       only  one number, 1 is returned instead of 0 (causing matching to back-
+       track) when a callout  of  that  number  is  reached.  If  two  numbers
+       (:)  are  given,  1  is  returned when callout  is reached and
+       there have been at least  callouts. The  callout_error  modifier  is
+       similar,  except  that  PCRE2_ERROR_CALLOUT  is  returned,  causing the
+       entire matching process to be aborted. If both these modifiers are  set
        for the same callout number, callout_error takes precedence.
 
-       Note that callouts with string arguments are always  given  the  number
+       Note  that  callouts  with string arguments are always given the number
        zero. See "Callouts" below for a description of the output when a call-
        out it taken.
 
-       The callout_data modifier can be given an unsigned or a  negative  num-
-       ber.   This  is  set  as the "user data" that is passed to the matching
-       function, and passed back when the callout  function  is  invoked.  Any
-       value  other  than  zero  is  used as a return from pcre2test's callout
+       The  callout_data  modifier can be given an unsigned or a negative num-
+       ber.  This is set as the "user data" that is  passed  to  the  matching
+       function,  and  passed  back  when the callout function is invoked. Any
+       value other than zero is used as  a  return  from  pcre2test's  callout
        function.
 
    Finding all matches in a string
 
        Searching for all possible matches within a subject can be requested by
-       the  global  or altglobal modifier. After finding a match, the matching
-       function is called again to search the remainder of  the  subject.  The
-       difference  between  global  and  altglobal is that the former uses the
-       start_offset argument to pcre2_match() or  pcre2_dfa_match()  to  start
-       searching  at  a new point within the entire string (which is what Perl
+       the global or altglobal modifier. After finding a match,  the  matching
+       function  is  called  again to search the remainder of the subject. The
+       difference between global and altglobal is that  the  former  uses  the
+       start_offset  argument  to  pcre2_match() or pcre2_dfa_match() to start
+       searching at a new point within the entire string (which is  what  Perl
        does), whereas the latter passes over a shortened subject. This makes a
        difference to the matching process if the pattern begins with a lookbe-
        hind assertion (including \b or \B).
 
-       If an empty string  is  matched,  the  next  match  is  done  with  the
+       If  an  empty  string  is  matched,  the  next  match  is done with the
        PCRE2_NOTEMPTY_ATSTART and PCRE2_ANCHORED flags set, in order to search
        for another, non-empty, match at the same point in the subject. If this
-       match  fails,  the  start  offset  is advanced, and the normal match is
-       retried. This imitates the way Perl handles such cases when  using  the
-       /g  modifier  or  the  split()  function. Normally, the start offset is
-       advanced by one character, but if  the  newline  convention  recognizes
-       CRLF  as  a newline, and the current character is CR followed by LF, an
+       match fails, the start offset is advanced,  and  the  normal  match  is
+       retried.  This  imitates the way Perl handles such cases when using the
+       /g modifier or the split() function.  Normally,  the  start  offset  is
+       advanced  by  one  character,  but if the newline convention recognizes
+       CRLF as a newline, and the current character is CR followed by  LF,  an
        advance of two characters occurs.
 
    Testing substring extraction functions
 
-       The copy  and  get  modifiers  can  be  used  to  test  the  pcre2_sub-
+       The  copy  and  get  modifiers  can  be  used  to  test  the pcre2_sub-
        string_copy_xxx() and pcre2_substring_get_xxx() functions.  They can be
-       given more than once, and each can specify a group name or number,  for
+       given  more than once, and each can specify a group name or number, for
        example:
 
           abcd\=copy=1,copy=3,get=G1
 
-       If  the  #subject command is used to set default copy and/or get lists,
-       these can be unset by specifying a negative number to cancel  all  num-
+       If the #subject command is used to set default copy and/or  get  lists,
+       these  can  be unset by specifying a negative number to cancel all num-
        bered groups and an empty name to cancel all named groups.
 
-       The  getall  modifier  tests pcre2_substring_list_get(), which extracts
+       The getall modifier tests  pcre2_substring_list_get(),  which  extracts
        all captured substrings.
 
-       If the subject line is successfully matched, the  substrings  extracted
-       by  the  convenience  functions  are  output  with C, G, or L after the
-       string number instead of a colon. This is in  addition  to  the  normal
-       full  list.  The string length (that is, the return from the extraction
+       If  the  subject line is successfully matched, the substrings extracted
+       by the convenience functions are output with  C,  G,  or  L  after  the
+       string  number  instead  of  a colon. This is in addition to the normal
+       full list. The string length (that is, the return from  the  extraction
        function) is given in parentheses after each substring, followed by the
        name when the extraction was by name.
 
    Testing the substitution function
 
-       If  the  replace  modifier  is  set, the pcre2_substitute() function is
-       called instead of one of the matching functions. Note that  replacement
-       strings  cannot  contain commas, because a comma signifies the end of a
+       If the replace modifier is  set,  the  pcre2_substitute()  function  is
+       called  instead of one of the matching functions. Note that replacement
+       strings cannot contain commas, because a comma signifies the end  of  a
        modifier. This is not thought to be an issue in a test program.
 
-       Unlike subject strings, pcre2test does not process replacement  strings
-       for  escape  sequences. In UTF mode, a replacement string is checked to
-       see if it is a valid UTF-8 string. If so, it is correctly converted  to
-       a  UTF  string of the appropriate code unit width. If it is not a valid
-       UTF-8 string, the individual code units are copied directly. This  pro-
+       Unlike  subject strings, pcre2test does not process replacement strings
+       for escape sequences. In UTF mode, a replacement string is  checked  to
+       see  if it is a valid UTF-8 string. If so, it is correctly converted to
+       a UTF string of the appropriate code unit width. If it is not  a  valid
+       UTF-8  string, the individual code units are copied directly. This pro-
        vides a means of passing an invalid UTF-8 string for testing purposes.
 
-       The  following modifiers set options (in additional to the normal match
+       The following modifiers set options (in additional to the normal  match
        options) for pcre2_substitute():
 
          global                      PCRE2_SUBSTITUTE_GLOBAL
@@ -1154,8 +1158,8 @@ SUBJECT MODIFIERS
          substitute_unset_empty      PCRE2_SUBSTITUTE_UNSET_EMPTY
 
 
-       After a successful substitution, the modified string  is  output,  pre-
-       ceded  by the number of replacements. This may be zero if there were no
+       After  a  successful  substitution, the modified string is output, pre-
+       ceded by the number of replacements. This may be zero if there were  no
        matches. Here is a simple example of a substitution test:
 
          /abc/replace=xxx
@@ -1164,12 +1168,12 @@ SUBJECT MODIFIERS
              =abc=abc=\=global
           2: =xxx=xxx=
 
-       Subject and replacement strings should be kept relatively short  (fewer
-       than  256 characters) for substitution tests, as fixed-size buffers are
-       used. To make it easy to test for buffer overflow, if  the  replacement
-       string  starts  with a number in square brackets, that number is passed
-       to pcre2_substitute() as the  size  of  the  output  buffer,  with  the
-       replacement  string  starting at the next character. Here is an example
+       Subject  and replacement strings should be kept relatively short (fewer
+       than 256 characters) for substitution tests, as fixed-size buffers  are
+       used.  To  make it easy to test for buffer overflow, if the replacement
+       string starts with a number in square brackets, that number  is  passed
+       to  pcre2_substitute()  as  the  size  of  the  output buffer, with the
+       replacement string starting at the next character. Here is  an  example
        that tests the edge case:
 
          /abc/
@@ -1178,11 +1182,11 @@ SUBJECT MODIFIERS
              123abc123\=replace=[9]XYZ
          Failed: error -47: no more memory
 
-       The   default   action   of    pcre2_substitute()    is    to    return
-       PCRE2_ERROR_NOMEMORY  when  the output buffer is too small. However, if
-       the PCRE2_SUBSTITUTE_OVERFLOW_LENGTH option is set (by using  the  sub-
-       stitute_overflow_length  modifier),  pcre2_substitute() continues to go
-       through the motions of matching and substituting, in order  to  compute
+       The    default    action    of    pcre2_substitute()   is   to   return
+       PCRE2_ERROR_NOMEMORY when the output buffer is too small.  However,  if
+       the  PCRE2_SUBSTITUTE_OVERFLOW_LENGTH  option is set (by using the sub-
+       stitute_overflow_length modifier), pcre2_substitute() continues  to  go
+       through  the  motions of matching and substituting, in order to compute
        the size of buffer that is required. When this happens, pcre2test shows
        the required buffer length (which includes space for the trailing zero)
        as part of the error message. For example:
@@ -1192,151 +1196,151 @@ SUBJECT MODIFIERS
          Failed: error -47: no more memory: 10 code units are needed
 
        A replacement string is ignored with POSIX and DFA matching. Specifying
-       partial matching provokes an error return  ("bad  option  value")  from
+       partial  matching  provokes  an  error return ("bad option value") from
        pcre2_substitute().
 
    Setting the JIT stack size
 
-       The  jitstack modifier provides a way of setting the maximum stack size
-       that is used by the just-in-time optimization code. It  is  ignored  if
+       The jitstack modifier provides a way of setting the maximum stack  size
+       that  is  used  by the just-in-time optimization code. It is ignored if
        JIT optimization is not being used. The value is a number of kilobytes.
        Providing a stack that is larger than the default 32K is necessary only
        for very complicated patterns.
 
    Setting heap, match, and depth limits
 
-       The  heap_limit,  match_limit, and depth_limit modifiers set the appro-
-       priate limits in the match context. These values are ignored  when  the
+       The heap_limit, match_limit, and depth_limit modifiers set  the  appro-
+       priate  limits  in the match context. These values are ignored when the
        find_limits modifier is specified.
 
    Finding minimum limits
 
-       If  the  find_limits  modifier  is present on a subject line, pcre2test
-       calls the relevant matching function several times,  setting  different
-       values    in    the    match    context   via   pcre2_set_heap_limit(),
-       pcre2_set_match_limit(), or pcre2_set_depth_limit() until it finds  the
-       minimum  values  for  each  parameter that allows the match to complete
+       If the find_limits modifier is present on  a  subject  line,  pcre2test
+       calls  the  relevant matching function several times, setting different
+       values   in   the    match    context    via    pcre2_set_heap_limit(),
+       pcre2_set_match_limit(),  or pcre2_set_depth_limit() until it finds the
+       minimum values for each parameter that allows  the  match  to  complete
        without error.
 
        If JIT is being used, only the match limit is relevant. If DFA matching
        is being used, only the depth limit is relevant.
 
-       The  match_limit number is a measure of the amount of backtracking that
-       takes place, and learning the minimum value  can  be  instructive.  For
-       most  simple  matches, the number is quite small, but for patterns with
-       very large numbers of matching possibilities, it can become large  very
+       The match_limit number is a measure of the amount of backtracking  that
+       takes  place,  and  learning  the minimum value can be instructive. For
+       most simple matches, the number is quite small, but for  patterns  with
+       very  large numbers of matching possibilities, it can become large very
        quickly with increasing length of subject string.
 
-       For  non-DFA  matching,  the minimum depth_limit number is a measure of
+       For non-DFA matching, the minimum depth_limit number is  a  measure  of
        how much nested backtracking happens (that is, how deeply the pattern's
-       tree  is  searched).  In the case of DFA matching, depth_limit controls
-       the depth of recursive calls of the internal function that is used  for
+       tree is searched). In the case of DFA  matching,  depth_limit  controls
+       the  depth of recursive calls of the internal function that is used for
        handling pattern recursion, lookaround assertions, and atomic groups.
 
    Showing MARK names
 
 
        The mark modifier causes the names from backtracking control verbs that
-       are returned from calls to pcre2_match() to be displayed. If a mark  is
-       returned  for a match, non-match, or partial match, pcre2test shows it.
-       For a match, it is on a line by itself, tagged with  "MK:".  Otherwise,
+       are  returned from calls to pcre2_match() to be displayed. If a mark is
+       returned for a match, non-match, or partial match, pcre2test shows  it.
+       For  a  match, it is on a line by itself, tagged with "MK:". Otherwise,
        it is added to the non-match message.
 
    Showing memory usage
 
-       The  memory modifier causes pcre2test to log the sizes of all heap mem-
-       ory  allocation  and  freeing  calls  that  occur  during  a  call   to
-       pcre2_match().  These  occur only when a match requires a bigger vector
-       than the default for remembering backtracking  points.  In  many  cases
-       there  will  be no heap memory used and therefore no additional output.
-       No heap memory is allocated during  matching  with  pcre2_dfa_match  or
-       with  JIT,  so in those cases the memory modifier never has any effect.
+       The memory modifier causes pcre2test to log the sizes of all heap  mem-
+       ory   allocation  and  freeing  calls  that  occur  during  a  call  to
+       pcre2_match(). These occur only when a match requires a  bigger  vector
+       than  the  default  for  remembering backtracking points. In many cases
+       there will be no heap memory used and therefore no  additional  output.
+       No  heap  memory  is  allocated during matching with pcre2_dfa_match or
+       with JIT, so in those cases the memory modifier never has  any  effect.
        For this modifier to work, the null_context modifier must not be set on
-       both  the  pattern  and the subject, though it can be set on one or the
+       both the pattern and the subject, though it can be set on  one  or  the
        other.
 
    Setting a starting offset
 
-       The offset modifier sets an offset  in  the  subject  string  at  which
+       The  offset  modifier  sets  an  offset  in the subject string at which
        matching starts. Its value is a number of code units, not characters.
 
    Setting an offset limit
 
-       The  offset_limit  modifier  sets  a limit for unanchored matches. If a
+       The offset_limit modifier sets a limit for  unanchored  matches.  If  a
        match cannot be found starting at or before this offset in the subject,
        a "no match" return is given. The data value is a number of code units,
-       not characters. When this modifier is used, the use_offset_limit  modi-
+       not  characters. When this modifier is used, the use_offset_limit modi-
        fier must have been set for the pattern; if not, an error is generated.
 
    Setting the size of the output vector
 
-       The  ovector  modifier  applies  only  to  the subject line in which it
-       appears, though of course it can also be used to set  a  default  in  a
-       #subject  command. It specifies the number of pairs of offsets that are
+       The ovector modifier applies only to  the  subject  line  in  which  it
+       appears,  though  of  course  it can also be used to set a default in a
+       #subject command. It specifies the number of pairs of offsets that  are
        available for storing matching information. The default is 15.
 
-       A value of zero is useful when testing the POSIX API because it  causes
+       A  value of zero is useful when testing the POSIX API because it causes
        regexec() to be called with a NULL capture vector. When not testing the
-       POSIX API, a value of  zero  is  used  to  cause  pcre2_match_data_cre-
-       ate_from_pattern()  to  be  called, in order to create a match block of
+       POSIX  API,  a  value  of  zero  is used to cause pcre2_match_data_cre-
+       ate_from_pattern() to be called, in order to create a  match  block  of
        exactly the right size for the pattern. (It is not possible to create a
-       match  block  with  a zero-length ovector; there is always at least one
+       match block with a zero-length ovector; there is always  at  least  one
        pair of offsets.)
 
    Passing the subject as zero-terminated
 
        By default, the subject string is passed to a native API matching func-
        tion with its correct length. In order to test the facility for passing
-       a zero-terminated string, the zero_terminate modifier is  provided.  It
+       a  zero-terminated  string, the zero_terminate modifier is provided. It
        causes the length to be passed as PCRE2_ZERO_TERMINATED. (When matching
-       via the POSIX interface, this modifier has no effect, as  there  is  no
+       via  the  POSIX  interface, this modifier has no effect, as there is no
        facility for passing a length.)
 
-       When  testing  pcre2_substitute(), this modifier also has the effect of
+       When testing pcre2_substitute(), this modifier also has the  effect  of
        passing the replacement string as zero-terminated.
 
    Passing a NULL context
 
-       Normally,  pcre2test  passes  a   context   block   to   pcre2_match(),
+       Normally,   pcre2test   passes   a   context  block  to  pcre2_match(),
        pcre2_dfa_match() or pcre2_jit_match(). If the null_context modifier is
-       set, however, NULL is passed. This is for  testing  that  the  matching
+       set,  however,  NULL  is  passed. This is for testing that the matching
        functions behave correctly in this case (they use default values). This
-       modifier cannot be used with the find_limits modifier or  when  testing
+       modifier  cannot  be used with the find_limits modifier or when testing
        the substitution function.
 
 
 THE ALTERNATIVE MATCHING FUNCTION
 
-       By  default,  pcre2test  uses  the  standard  PCRE2  matching function,
+       By default,  pcre2test  uses  the  standard  PCRE2  matching  function,
        pcre2_match() to match each subject line. PCRE2 also supports an alter-
-       native  matching  function, pcre2_dfa_match(), which operates in a dif-
-       ferent way, and has some restrictions. The differences between the  two
+       native matching function, pcre2_dfa_match(), which operates in  a  dif-
+       ferent  way, and has some restrictions. The differences between the two
        functions are described in the pcre2matching documentation.
 
-       If  the dfa modifier is set, the alternative matching function is used.
-       This function finds all possible matches at a given point in  the  sub-
-       ject.  If,  however, the dfa_shortest modifier is set, processing stops
-       after the first match is found. This is always  the  shortest  possible
+       If the dfa modifier is set, the alternative matching function is  used.
+       This  function  finds all possible matches at a given point in the sub-
+       ject. If, however, the dfa_shortest modifier is set,  processing  stops
+       after  the  first  match is found. This is always the shortest possible
        match.
 
 
 DEFAULT OUTPUT FROM pcre2test
 
-       This  section  describes  the output when the normal matching function,
+       This section describes the output when the  normal  matching  function,
        pcre2_match(), is being used.
 
-       When a match succeeds, pcre2test outputs  the  list  of  captured  sub-
-       strings,  starting  with number 0 for the string that matched the whole
-       pattern.   Otherwise,  it  outputs  "No  match"  when  the  return   is
-       PCRE2_ERROR_NOMATCH,  or  "Partial  match:"  followed  by the partially
-       matching substring when the return is PCRE2_ERROR_PARTIAL.  (Note  that
-       this  is  the  entire  substring  that was inspected during the partial
-       match; it may include characters before the actual  match  start  if  a
+       When  a  match  succeeds,  pcre2test  outputs the list of captured sub-
+       strings, starting with number 0 for the string that matched  the  whole
+       pattern.    Otherwise,  it  outputs  "No  match"  when  the  return  is
+       PCRE2_ERROR_NOMATCH, or "Partial  match:"  followed  by  the  partially
+       matching  substring  when the return is PCRE2_ERROR_PARTIAL. (Note that
+       this is the entire substring that  was  inspected  during  the  partial
+       match;  it  may  include  characters before the actual match start if a
        lookbehind assertion, \K, \b, or \B was involved.)
 
        For any other return, pcre2test outputs the PCRE2 negative error number
-       and a short descriptive phrase. If the error is  a  failed  UTF  string
-       check,  the  code  unit offset of the start of the failing character is
+       and  a  short  descriptive  phrase. If the error is a failed UTF string
+       check, the code unit offset of the start of the  failing  character  is
        also output. Here is an example of an interactive pcre2test run.
 
          $ pcre2test
@@ -1352,8 +1356,8 @@ DEFAULT OUTPUT FROM pcre2test
        Unset capturing substrings that are not followed by one that is set are
        not shown by pcre2test unless the allcaptures modifier is specified. In
        the following example, there are two capturing substrings, but when the
-       first  data  line is matched, the second, unset substring is not shown.
-       An "internal" unset substring is shown as "", as for the  second
+       first data line is matched, the second, unset substring is  not  shown.
+       An  "internal" unset substring is shown as "", as for the second
        data line.
 
            re> /(a)|(b)/
@@ -1365,11 +1369,11 @@ DEFAULT OUTPUT FROM pcre2test
           1: 
           2: b
 
-       If  the strings contain any non-printing characters, they are output as
-       \xhh escapes if the value is less than 256 and UTF  mode  is  not  set.
+       If the strings contain any non-printing characters, they are output  as
+       \xhh  escapes  if  the  value is less than 256 and UTF mode is not set.
        Otherwise they are output as \x{hh...} escapes. See below for the defi-
-       nition of non-printing characters. If the aftertext  modifier  is  set,
-       the  output  for substring 0 is followed by the the rest of the subject
+       nition  of  non-printing  characters. If the aftertext modifier is set,
+       the output for substring 0 is followed by the the rest of  the  subject
        string, identified by "0+" like this:
 
            re> /cat/aftertext
@@ -1377,7 +1381,7 @@ DEFAULT OUTPUT FROM pcre2test
           0: cat
           0+ aract
 
-       If global matching is requested, the  results  of  successive  matching
+       If  global  matching  is  requested, the results of successive matching
        attempts are output in sequence, like this:
 
            re> /\Bi(\w\w)/g
@@ -1389,8 +1393,8 @@ DEFAULT OUTPUT FROM pcre2test
           0: ipp
           1: pp
 
-       "No  match" is output only if the first match attempt fails. Here is an
-       example of a failure message (the offset 4 that  is  specified  by  the
+       "No match" is output only if the first match attempt fails. Here is  an
+       example  of  a  failure  message (the offset 4 that is specified by the
        offset modifier is past the end of the subject string):
 
            re> /xyz/
@@ -1398,7 +1402,7 @@ DEFAULT OUTPUT FROM pcre2test
          Error -24 (bad offset value)
 
        Note that whereas patterns can be continued over several lines (a plain
-       ">" prompt is used for continuations), subject lines may  not.  However
+       ">"  prompt  is used for continuations), subject lines may not. However
        newlines can be included in a subject by means of the \n escape (or \r,
        \r\n, etc., depending on the newline sequence setting).
 
@@ -1406,7 +1410,7 @@ DEFAULT OUTPUT FROM pcre2test
 OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION
 
        When the alternative matching function, pcre2_dfa_match(), is used, the
-       output  consists  of  a list of all the matches that start at the first
+       output consists of a list of all the matches that start  at  the  first
        point in the subject where there is at least one match. For example:
 
            re> /(tang|tangerine|tan)/
@@ -1415,11 +1419,11 @@ OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION
           1: tang
           2: tan
 
-       Using the normal matching function on this data finds only "tang".  The
-       longest  matching  string  is  always  given first (and numbered zero).
-       After a PCRE2_ERROR_PARTIAL return, the  output  is  "Partial  match:",
-       followed  by  the  partially  matching substring. Note that this is the
-       entire substring that was inspected during the partial  match;  it  may
+       Using  the normal matching function on this data finds only "tang". The
+       longest matching string is always  given  first  (and  numbered  zero).
+       After  a  PCRE2_ERROR_PARTIAL  return,  the output is "Partial match:",
+       followed by the partially matching substring. Note  that  this  is  the
+       entire  substring  that  was inspected during the partial match; it may
        include characters before the actual match start if a lookbehind asser-
        tion, \b, or \B was involved. (\K is not supported for DFA matching.)
 
@@ -1435,16 +1439,16 @@ OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION
           1: tan
           0: tan
 
-       The  alternative  matching function does not support substring capture,
-       so the modifiers that are concerned with captured  substrings  are  not
+       The alternative matching function does not support  substring  capture,
+       so  the  modifiers  that are concerned with captured substrings are not
        relevant.
 
 
 RESTARTING AFTER A PARTIAL MATCH
 
-       When  the  alternative matching function has given the PCRE2_ERROR_PAR-
+       When the alternative matching function has given  the  PCRE2_ERROR_PAR-
        TIAL return, indicating that the subject partially matched the pattern,
-       you  can restart the match with additional subject data by means of the
+       you can restart the match with additional subject data by means of  the
        dfa_restart modifier. For example:
 
            re> /^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/
@@ -1453,45 +1457,45 @@ RESTARTING AFTER A PARTIAL MATCH
          data> n05\=dfa,dfa_restart
           0: n05
 
-       For further information about partial matching,  see  the  pcre2partial
+       For  further  information  about partial matching, see the pcre2partial
        documentation.
 
 
 CALLOUTS
 
        If the pattern contains any callout requests, pcre2test's callout func-
-       tion is called during matching unless callout_none is specified.   This
+       tion  is called during matching unless callout_none is specified.  This
        works with both matching functions.
 
-       The  callout  function in pcre2test returns zero (carry on matching) by
-       default, but you can use a callout_fail modifier in a subject line  (as
+       The callout function in pcre2test returns zero (carry on  matching)  by
+       default,  but you can use a callout_fail modifier in a subject line (as
        described above) to change this and other parameters of the callout.
 
        Inserting callouts can be helpful when using pcre2test to check compli-
-       cated regular expressions. For further information about callouts,  see
+       cated  regular expressions. For further information about callouts, see
        the pcre2callout documentation.
 
-       The  output for callouts with numerical arguments and those with string
+       The output for callouts with numerical arguments and those with  string
        arguments is slightly different.
 
    Callouts with numerical arguments
 
        By default, the callout function displays the callout number, the start
-       and  current positions in the subject text at the callout time, and the
+       and current positions in the subject text at the callout time, and  the
        next pattern item to be tested. For example:
 
          --->pqrabcdef
            0    ^  ^     \d
 
-       This output indicates that  callout  number  0  occurred  for  a  match
-       attempt  starting  at  the fourth character of the subject string, when
-       the pointer was at the seventh character, and  when  the  next  pattern
-       item  was  \d.  Just  one circumflex is output if the start and current
-       positions are the same, or if the current position precedes  the  start
+       This  output  indicates  that  callout  number  0  occurred for a match
+       attempt starting at the fourth character of the  subject  string,  when
+       the  pointer  was  at  the seventh character, and when the next pattern
+       item was \d. Just one circumflex is output if  the  start  and  current
+       positions  are  the same, or if the current position precedes the start
        position, which can happen if the callout is in a lookbehind assertion.
 
        Callouts numbered 255 are assumed to be automatic callouts, inserted as
-       a result of the /auto_callout pattern modifier. In this  case,  instead
+       a  result  of the /auto_callout pattern modifier. In this case, instead
        of showing the callout number, the offset in the pattern, preceded by a
        plus, is output. For example:
 
@@ -1505,7 +1509,7 @@ CALLOUTS
           0: E*
 
        If a pattern contains (*MARK) items, an additional line is output when-
-       ever  a  change  of  latest mark is passed to the callout function. For
+       ever a change of latest mark is passed to  the  callout  function.  For
        example:
 
            re> /a(*MARK:X)bc/auto_callout
@@ -1519,17 +1523,17 @@ CALLOUTS
          +12 ^  ^
           0: abc
 
-       The mark changes between matching "a" and "b", but stays the  same  for
-       the  rest  of  the match, so nothing more is output. If, as a result of
-       backtracking, the mark reverts to being unset, the  text  ""  is
+       The  mark  changes between matching "a" and "b", but stays the same for
+       the rest of the match, so nothing more is output. If, as  a  result  of
+       backtracking,  the  mark  reverts to being unset, the text "" is
        output.
 
    Callouts with string arguments
 
        The output for a callout with a string argument is similar, except that
-       instead of outputting a callout number before the position  indicators,
-       the  callout  string  and  its  offset in the pattern string are output
-       before the reflection of the subject string, and the subject string  is
+       instead  of outputting a callout number before the position indicators,
+       the callout string and its offset in  the  pattern  string  are  output
+       before  the reflection of the subject string, and the subject string is
        reflected for each callout. For example:
 
            re> /^ab(?C'first')cd(?C"second")ef/
@@ -1546,43 +1550,43 @@ CALLOUTS
 NON-PRINTING CHARACTERS
 
        When pcre2test is outputting text in the compiled version of a pattern,
-       bytes other than 32-126 are always treated as  non-printing  characters
+       bytes  other  than 32-126 are always treated as non-printing characters
        and are therefore shown as hex escapes.
 
-       When  pcre2test  is outputting text that is a matched part of a subject
-       string, it behaves in the same way, unless a different locale has  been
-       set  for  the  pattern  (using  the locale modifier). In this case, the
-       isprint() function is used to  distinguish  printing  and  non-printing
+       When pcre2test is outputting text that is a matched part of  a  subject
+       string,  it behaves in the same way, unless a different locale has been
+       set for the pattern (using the locale  modifier).  In  this  case,  the
+       isprint()  function  is  used  to distinguish printing and non-printing
        characters.
 
 
 SAVING AND RESTORING COMPILED PATTERNS
 
-       It  is  possible  to  save  compiled patterns on disc or elsewhere, and
+       It is possible to save compiled patterns  on  disc  or  elsewhere,  and
        reload them later, subject to a number of restrictions. JIT data cannot
-       be  saved.  The host on which the patterns are reloaded must be running
+       be saved. The host on which the patterns are reloaded must  be  running
        the same version of PCRE2, with the same code unit width, and must also
-       have  the  same  endianness,  pointer width and PCRE2_SIZE type. Before
-       compiled patterns can be saved they must be serialized, that  is,  con-
-       verted  to a stream of bytes. A single byte stream may contain any num-
-       ber of compiled patterns, but they must  all  use  the  same  character
+       have the same endianness, pointer width  and  PCRE2_SIZE  type.  Before
+       compiled  patterns  can be saved they must be serialized, that is, con-
+       verted to a stream of bytes. A single byte stream may contain any  num-
+       ber  of  compiled  patterns,  but  they must all use the same character
        tables. A single copy of the tables is included in the byte stream (its
        size is 1088 bytes).
 
-       The functions whose names begin  with  pcre2_serialize_  are  used  for
-       serializing  and de-serializing. They are described in the pcre2serial-
+       The  functions  whose  names  begin  with pcre2_serialize_ are used for
+       serializing and de-serializing. They are described in the  pcre2serial-
        ize  documentation.  In  this  section  we  describe  the  features  of
        pcre2test that can be used to test these functions.
 
-       When  a  pattern  with  push  modifier  is successfully compiled, it is
-       pushed onto a stack of compiled patterns,  and  pcre2test  expects  the
-       next  line  to  contain a new pattern (or command) instead of a subject
-       line. By contrast, the pushcopy modifier causes a copy of the  compiled
-       pattern  to  be  stacked,  leaving the original available for immediate
-       matching. By using push and/or pushcopy, a number of  patterns  can  be
+       When a pattern with push  modifier  is  successfully  compiled,  it  is
+       pushed  onto  a  stack  of compiled patterns, and pcre2test expects the
+       next line to contain a new pattern (or command) instead  of  a  subject
+       line.  By contrast, the pushcopy modifier causes a copy of the compiled
+       pattern to be stacked, leaving the  original  available  for  immediate
+       matching.  By  using  push and/or pushcopy, a number of patterns can be
        compiled and retained. These modifiers are incompatible with posix, and
-       control modifiers that act at match time are ignored (with  a  message)
-       for  the  stacked patterns. The jitverify modifier applies only at com-
+       control  modifiers  that act at match time are ignored (with a message)
+       for the stacked patterns. The jitverify modifier applies only  at  com-
        pile time.
 
        The command
@@ -1590,21 +1594,21 @@ SAVING AND RESTORING COMPILED PATTERNS
          #save 
 
        causes all the stacked patterns to be serialized and the result written
-       to  the named file. Afterwards, all the stacked patterns are freed. The
+       to the named file. Afterwards, all the stacked patterns are freed.  The
        command
 
          #load 
 
-       reads the data in the file, and then arranges for it to  be  de-serial-
-       ized,  with the resulting compiled patterns added to the pattern stack.
-       The pattern on the top of the stack can be retrieved by the  #pop  com-
-       mand,  which  must  be  followed  by  lines  of subjects that are to be
-       matched with the pattern, terminated as usual by an empty line  or  end
-       of  file.  This  command  may be followed by a modifier list containing
-       only control modifiers that act after a pattern has been  compiled.  In
+       reads  the  data in the file, and then arranges for it to be de-serial-
+       ized, with the resulting compiled patterns added to the pattern  stack.
+       The  pattern  on the top of the stack can be retrieved by the #pop com-
+       mand, which must be followed by  lines  of  subjects  that  are  to  be
+       matched  with  the pattern, terminated as usual by an empty line or end
+       of file. This command may be followed by  a  modifier  list  containing
+       only  control  modifiers that act after a pattern has been compiled. In
        particular,  hex,  posix,  posix_nosub,  push,  and  pushcopy  are  not
-       allowed, nor are any option-setting modifiers.  The JIT modifiers  are,
-       however  permitted.  Here is an example that saves and reloads two pat-
+       allowed,  nor are any option-setting modifiers.  The JIT modifiers are,
+       however permitted. Here is an example that saves and reloads  two  pat-
        terns.
 
          /abc/push
@@ -1617,10 +1621,10 @@ SAVING AND RESTORING COMPILED PATTERNS
          #pop jit,bincode
          abc
 
-       If jitverify is used with #pop, it does not  automatically  imply  jit,
+       If  jitverify  is  used with #pop, it does not automatically imply jit,
        which is different behaviour from when it is used on a pattern.
 
-       The  #popcopy  command is analagous to the pushcopy modifier in that it
+       The #popcopy command is analagous to the pushcopy modifier in  that  it
        makes current a copy of the topmost stack pattern, leaving the original
        still on the stack.
 
@@ -1640,5 +1644,5 @@ AUTHOR
 
 REVISION
 
-       Last updated: 11 April 2017
+       Last updated: 17 April 2017
        Copyright (c) 1997-2017 University of Cambridge.
diff --git a/src/pcre2.h b/src/pcre2.h
index e15ede4..21f610d 100644
--- a/src/pcre2.h
+++ b/src/pcre2.h
@@ -137,6 +137,7 @@ D   is inspected during pcre2_dfa_match() execution
 #define PCRE2_ALT_CIRCUMFLEX      0x00200000u  /*   J M D */
 #define PCRE2_ALT_VERBNAMES       0x00400000u  /* C       */
 #define PCRE2_USE_OFFSET_LIMIT    0x00800000u  /*   J M D */
+#define PCRE2_EXTENDED_MORE       0x01000000u  /* C       */
 
 /* These are for pcre2_jit_compile(). */
 
diff --git a/src/pcre2.h.generic b/src/pcre2.h.generic
index e699b8a..21f610d 100644
--- a/src/pcre2.h.generic
+++ b/src/pcre2.h.generic
@@ -137,6 +137,7 @@ D   is inspected during pcre2_dfa_match() execution
 #define PCRE2_ALT_CIRCUMFLEX      0x00200000u  /*   J M D */
 #define PCRE2_ALT_VERBNAMES       0x00400000u  /* C       */
 #define PCRE2_USE_OFFSET_LIMIT    0x00800000u  /*   J M D */
+#define PCRE2_EXTENDED_MORE       0x01000000u  /* C       */
 
 /* These are for pcre2_jit_compile(). */
 
@@ -268,6 +269,7 @@ numbers must not be changed. */
 #define PCRE2_ERROR_BADSUBSPATTERN    (-60)
 #define PCRE2_ERROR_TOOMANYREPLACE    (-61)
 #define PCRE2_ERROR_BADSERIALIZEDDATA (-62)
+#define PCRE2_ERROR_HEAPLIMIT         (-63)
 
 /* Request types for pcre2_pattern_info() */
 
@@ -297,6 +299,7 @@ numbers must not be changed. */
 #define PCRE2_INFO_SIZE                 22
 #define PCRE2_INFO_HASBACKSLASHC        23
 #define PCRE2_INFO_FRAMESIZE            24
+#define PCRE2_INFO_HEAPLIMIT            25
 
 /* Request types for pcre2_config(). */
 
@@ -313,6 +316,7 @@ numbers must not be changed. */
 #define PCRE2_CONFIG_UNICODE                 9
 #define PCRE2_CONFIG_UNICODE_VERSION        10
 #define PCRE2_CONFIG_VERSION                11
+#define PCRE2_CONFIG_HEAPLIMIT              12
 
 /* Types for code units in patterns and subject strings. */
 
@@ -452,6 +456,8 @@ PCRE2_EXP_DECL int PCRE2_CALL_CONVENTION \
     int (*)(pcre2_callout_block *, void *), void *); \
 PCRE2_EXP_DECL int PCRE2_CALL_CONVENTION \
   pcre2_set_depth_limit(pcre2_match_context *, uint32_t); \
+PCRE2_EXP_DECL int PCRE2_CALL_CONVENTION \
+  pcre2_set_heap_limit(pcre2_match_context *, uint32_t); \
 PCRE2_EXP_DECL int PCRE2_CALL_CONVENTION \
   pcre2_set_match_limit(pcre2_match_context *, uint32_t); \
 PCRE2_EXP_DECL int PCRE2_CALL_CONVENTION \
@@ -676,6 +682,7 @@ pcre2_compile are called by application code. */
 #define pcre2_set_character_tables            PCRE2_SUFFIX(pcre2_set_character_tables_)
 #define pcre2_set_compile_recursion_guard     PCRE2_SUFFIX(pcre2_set_compile_recursion_guard_)
 #define pcre2_set_depth_limit                 PCRE2_SUFFIX(pcre2_set_depth_limit_)
+#define pcre2_set_heap_limit                  PCRE2_SUFFIX(pcre2_set_heap_limit_)
 #define pcre2_set_match_limit                 PCRE2_SUFFIX(pcre2_set_match_limit_)
 #define pcre2_set_max_pattern_length          PCRE2_SUFFIX(pcre2_set_max_pattern_length_)
 #define pcre2_set_newline                     PCRE2_SUFFIX(pcre2_set_newline_)
diff --git a/src/pcre2.h.in b/src/pcre2.h.in
index fb0042b..2411217 100644
--- a/src/pcre2.h.in
+++ b/src/pcre2.h.in
@@ -137,6 +137,7 @@ D   is inspected during pcre2_dfa_match() execution
 #define PCRE2_ALT_CIRCUMFLEX      0x00200000u  /*   J M D */
 #define PCRE2_ALT_VERBNAMES       0x00400000u  /* C       */
 #define PCRE2_USE_OFFSET_LIMIT    0x00800000u  /*   J M D */
+#define PCRE2_EXTENDED_MORE       0x01000000u  /* C       */
 
 /* These are for pcre2_jit_compile(). */
 
diff --git a/src/pcre2_compile.c b/src/pcre2_compile.c
index b4d7608..aa682d1 100644
--- a/src/pcre2_compile.c
+++ b/src/pcre2_compile.c
@@ -160,7 +160,7 @@ the length of compiled items varies with this.
 
 In the real compile phase, this workspace is not currently used. */
 
-#define COMPILE_WORK_SIZE (2048*LINK_SIZE)   /* Size in code units */
+#define COMPILE_WORK_SIZE (3000*LINK_SIZE)   /* Size in code units */
 
 #define C16_WORK_SIZE \
   ((COMPILE_WORK_SIZE * sizeof(PCRE2_UCHAR))/sizeof(uint16_t))
@@ -695,7 +695,8 @@ static int posix_substitutes[] = {
 #define PUBLIC_COMPILE_OPTIONS \
   (PCRE2_ANCHORED|PCRE2_ALLOW_EMPTY_CLASS|PCRE2_ALT_BSUX|PCRE2_ALT_CIRCUMFLEX| \
    PCRE2_ALT_VERBNAMES|PCRE2_AUTO_CALLOUT|PCRE2_CASELESS|PCRE2_DOLLAR_ENDONLY| \
-   PCRE2_DOTALL|PCRE2_DUPNAMES|PCRE2_ENDANCHORED|PCRE2_EXTENDED|PCRE2_FIRSTLINE| \
+   PCRE2_DOTALL|PCRE2_DUPNAMES|PCRE2_ENDANCHORED|PCRE2_EXTENDED| \
+   PCRE2_EXTENDED_MORE|PCRE2_FIRSTLINE| \
    PCRE2_MATCH_UNSET_BACKREF|PCRE2_MULTILINE|PCRE2_NEVER_BACKSLASH_C| \
    PCRE2_NEVER_UCP|PCRE2_NEVER_UTF|PCRE2_NO_AUTO_CAPTURE| \
    PCRE2_NO_AUTO_POSSESS|PCRE2_NO_DOTSTAR_ANCHOR|PCRE2_NO_START_OPTIMIZE| \
@@ -2226,12 +2227,17 @@ typedef struct nest_save {
   uint16_t  reset_group;
   uint16_t  max_group;
   uint16_t  flags;
+  uint32_t  options; 
 } nest_save;
 
-#define NSF_RESET      0x0001u
-#define NSF_EXTENDED   0x0002u
-#define NSF_DUPNAMES   0x0004u
-#define NSF_CONDASSERT 0x0008u
+#define NSF_RESET          0x0001u
+#define NSF_CONDASSERT     0x0002u
+
+/* These options (changeable within the pattern) are tracked during parsing.
+The rest are put into META_OPTIONS items and used when compiling. */
+
+#define PARSE_TRACKED_OPTIONS \
+  (PCRE2_EXTENDED|PCRE2_EXTENDED_MORE|PCRE2_DUPNAMES)
 
 /* States used for analyzing ranges in character classes. The two OK values
 must be last. */
@@ -2291,6 +2297,10 @@ creating a nest_save that spans the end of the workspace. */
 
 end_nests = (nest_save *)((char *)end_nests -
   ((cb->workspace_size * sizeof(PCRE2_UCHAR)) % sizeof(nest_save)));
+  
+/* PCRE2_EXTENDED_MORE implies PCRE2_EXTENDED */
+
+if ((options & PCRE2_EXTENDED_MORE) != 0) options |= PCRE2_EXTENDED; 
 
 /* Now scan the pattern */
 
@@ -2907,7 +2917,8 @@ while (ptr < ptrend)
 
     /* Process a regular character class. If the first character is '^', set
     the negation flag. If the first few characters (either before or after ^)
-    are \Q\E or \E we skip them too. This makes for compatibility with Perl. */
+    are \Q\E or \E or space or tab in extended-more mode, we skip them too.
+    This makes for compatibility with Perl. */
 
     negate_class = FALSE;
     while (ptr < ptrend)
@@ -2922,6 +2933,9 @@ while (ptr < ptrend)
         else
           break;
         }
+      else if ((options & PCRE2_EXTENDED_MORE) != 0 &&
+               (c == CHAR_SPACE || c == CHAR_HT))  /* Note: just these two */
+        continue;
       else if (!negate_class && c == CHAR_CIRCUMFLEX_ACCENT)
         negate_class = TRUE;
       else break;
@@ -2955,7 +2969,7 @@ while (ptr < ptrend)
     for (;;)
       {
       BOOL char_is_literal = TRUE;
-
+      
       /* Inside \Q...\E everything is literal except \E */
 
       if (inescq)
@@ -2968,6 +2982,12 @@ while (ptr < ptrend)
           }
         goto CLASS_LITERAL;
         }
+        
+      /* Skip over space and tab (only) in extended-more mode. */
+      
+      if ((options & PCRE2_EXTENDED_MORE) != 0 && 
+          (c == CHAR_SPACE || c == CHAR_HT)) 
+        goto CLASS_CONTINUE;
 
       /* Handle POSIX class names. Perl allows a negation extension of the
       form [:^name:]. A square bracket that doesn't match the syntax is
@@ -3387,8 +3407,7 @@ while (ptr < ptrend)
         }
       top_nest->nest_depth = nest_depth;
       top_nest->flags = 0;
-      if ((options & PCRE2_EXTENDED) != 0) top_nest->flags |= NSF_EXTENDED;
-      if ((options & PCRE2_DUPNAMES) != 0) top_nest->flags |= NSF_DUPNAMES;
+      top_nest->options = options & PARSE_TRACKED_OPTIONS;
 
       /* Start of non-capturing group that resets the capture count for each
       branch. */
@@ -3403,9 +3422,9 @@ while (ptr < ptrend)
         ptr++;
         }
 
-      /* Scan for options imsxJU. We need to keep track of (?x) and (?J) for
-      use while scanning. The other options are used during the compiling
-      phases. */
+      /* Scan for options imsxJU. Some of them are tracked during parsing (see 
+      PARSE_TRACKED_OPTIONS) as they are local to groups. Others are not needed 
+      till compile time. */ 
 
       else
         {
@@ -3429,8 +3448,14 @@ while (ptr < ptrend)
             case CHAR_i: *optset |= PCRE2_CASELESS; break;
             case CHAR_m: *optset |= PCRE2_MULTILINE; break;
             case CHAR_s: *optset |= PCRE2_DOTALL; break;
-            case CHAR_x: *optset |= PCRE2_EXTENDED; break;
             case CHAR_U: *optset |= PCRE2_UNGREEDY; break;
+            
+            /* If x appears twice it sets the extended extended option. */
+            
+            case CHAR_x: 
+            *optset |= ((*optset & PCRE2_EXTENDED) != 0)?
+              PCRE2_EXTENDED_MORE : PCRE2_EXTENDED; 
+            break;
 
             default:
             errorcode = ERR11;
@@ -3439,6 +3464,10 @@ while (ptr < ptrend)
             }
           }
         options = (options | set) & (~unset);
+        
+        /* Unsetting extended should also get rid of extended-more. */
+        
+        if ((options & PCRE2_EXTENDED) == 0) options &= ~PCRE2_EXTENDED_MORE;  
 
         /* If the options ended with ')' this is not the start of a nested
         group with option changes, so the options change at this level.
@@ -3916,8 +3945,7 @@ while (ptr < ptrend)
           }
         top_nest->nest_depth = nest_depth;
         top_nest->flags = NSF_CONDASSERT;
-        if ((options & PCRE2_EXTENDED) != 0) top_nest->flags |= NSF_EXTENDED;
-        if ((options & PCRE2_DUPNAMES) != 0) top_nest->flags |= NSF_DUPNAMES;
+        top_nest->options = options & PARSE_TRACKED_OPTIONS;
         }
       break;
 
@@ -4038,20 +4066,17 @@ while (ptr < ptrend)
     break;
 
     /* End of group; reset the capture count to the maximum if we are in a (?|
-    group and/or reset the extended and dupnames options. Disallow quantifier
-    for a condition that is an assertion. */
+    group and/or reset the options that are tracked during parsing. Disallow
+    quantifier for a condition that is an assertion. */
 
     case CHAR_RIGHT_PARENTHESIS:
     okquantifier = TRUE;
     if (top_nest != NULL && top_nest->nest_depth == nest_depth)
       {
+      options = (options & ~PARSE_TRACKED_OPTIONS) | top_nest->options;
       if ((top_nest->flags & NSF_RESET) != 0 &&
           top_nest->max_group > cb->bracount)
         cb->bracount = top_nest->max_group;
-      if ((top_nest->flags & NSF_EXTENDED) != 0) options |= PCRE2_EXTENDED;
-        else options &= ~PCRE2_EXTENDED;
-      if ((top_nest->flags & NSF_DUPNAMES) != 0) options |= PCRE2_DUPNAMES;
-        else options &= ~PCRE2_DUPNAMES;
       if ((top_nest->flags & NSF_CONDASSERT) != 0)
         okquantifier = FALSE;
       if (top_nest == (nest_save *)(cb->start_workspace)) top_nest = NULL;
diff --git a/src/pcre2test.c b/src/pcre2test.c
index 63ab73e..e41bfff 100644
--- a/src/pcre2test.c
+++ b/src/pcre2test.c
@@ -580,6 +580,7 @@ static modstruct modlist[] = {
   { "endanchored",                MOD_PD,   MOD_OPT, PCRE2_ENDANCHORED,          PD(options) },
   { "expand",                     MOD_PAT,  MOD_CTL, CTL_EXPAND,                 PO(control) },
   { "extended",                   MOD_PATP, MOD_OPT, PCRE2_EXTENDED,             PO(options) },
+  { "extended_more",              MOD_PATP, MOD_OPT, PCRE2_EXTENDED_MORE,        PO(options) },
   { "find_limits",                MOD_DAT,  MOD_CTL, CTL_FINDLIMITS,             DO(control) },
   { "firstline",                  MOD_PAT,  MOD_OPT, PCRE2_FIRSTLINE,            PO(options) },
   { "framesize",                  MOD_PAT,  MOD_CTL, CTL_FRAMESIZE,              PO(control) },
@@ -3464,7 +3465,17 @@ for (;;)
 
       field = check_modifier(modlist + index, ctx, pctl, dctl, *p);
       if (field == NULL) return FALSE;
-      *((uint32_t *)field) |= modlist[index].value;
+      
+      /* /x is a special case; a second appearance changes PCRE2_EXTENDED to
+      PCRE2_EXTENDED_MORE. */ 
+      
+      if (cc == 'x' && (*((uint32_t *)field) & PCRE2_EXTENDED) != 0)
+        { 
+        *((uint32_t *)field) &= ~PCRE2_EXTENDED;
+        *((uint32_t *)field) |= PCRE2_EXTENDED_MORE;
+        } 
+      else
+        *((uint32_t *)field) |= modlist[index].value;
       }
 
     continue;    /* With tne next (fullname) modifier */
@@ -3842,7 +3853,7 @@ static void
 show_compile_options(uint32_t options, const char *before, const char *after)
 {
 if (options == 0) fprintf(outfile, "%s %s", before, after);
-else fprintf(outfile, "%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s",
+else fprintf(outfile, "%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s",
   before,
   ((options & PCRE2_ALT_BSUX) != 0)? " alt_bsux" : "",
   ((options & PCRE2_ALT_CIRCUMFLEX) != 0)? " alt_circumflex" : "",
@@ -3856,6 +3867,7 @@ else fprintf(outfile, "%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%
   ((options & PCRE2_DUPNAMES) != 0)? " dupnames" : "",
   ((options & PCRE2_ENDANCHORED) != 0)? " endanchored" : "",
   ((options & PCRE2_EXTENDED) != 0)? " extended" : "",
+  ((options & PCRE2_EXTENDED_MORE) != 0)? " extended_more" : "",
   ((options & PCRE2_FIRSTLINE) != 0)? " firstline" : "",
   ((options & PCRE2_MATCH_UNSET_BACKREF) != 0)? " match_unset_backref" : "",
   ((options & PCRE2_MULTILINE) != 0)? " multiline" : "",
diff --git a/testdata/testinput2 b/testdata/testinput2
index 57e9521..8afde1b 100644
--- a/testdata/testinput2
+++ b/testdata/testinput2
@@ -5245,4 +5245,18 @@ a)"xI
 
 # ----------------------------------------------------------------------
 
+/[a b c]/BxxI
+
+/[a b c]/BxxxI
+
+/[a b c]/B,extended_more
+
+/[ a b c ]/B,extended_more
+
+/[a b](?xx: [ 12 ] (?-xx:[ 34 ]) )y z/B
+
+# Unsetting /x also unsets /xx
+
+/[a b](?xx: [ 12 ] (?-x:[ 34 ]) )y z/B
+
 # End of testinput2 
diff --git a/testdata/testoutput2 b/testdata/testoutput2
index f81d85a..dff7657 100644
--- a/testdata/testoutput2
+++ b/testdata/testoutput2
@@ -15873,6 +15873,78 @@ Failed: error -37: callout error code
 
 # ----------------------------------------------------------------------
 
+/[a b c]/BxxI
+------------------------------------------------------------------
+        Bra
+        [a-c]
+        Ket
+        End
+------------------------------------------------------------------
+Capturing subpattern count = 0
+Options: extended_more
+Starting code units: a b c 
+Subject length lower bound = 1
+
+/[a b c]/BxxxI
+------------------------------------------------------------------
+        Bra
+        [a-c]
+        Ket
+        End
+------------------------------------------------------------------
+Capturing subpattern count = 0
+Options: extended extended_more
+Starting code units: a b c 
+Subject length lower bound = 1
+
+/[a b c]/B,extended_more
+------------------------------------------------------------------
+        Bra
+        [a-c]
+        Ket
+        End
+------------------------------------------------------------------
+
+/[ a b c ]/B,extended_more
+------------------------------------------------------------------
+        Bra
+        [a-c]
+        Ket
+        End
+------------------------------------------------------------------
+
+/[a b](?xx: [ 12 ] (?-xx:[ 34 ]) )y z/B
+------------------------------------------------------------------
+        Bra
+        [ ab]
+        Bra
+        [12]
+        Bra
+        [ 34]
+        Ket
+        Ket
+        y z
+        Ket
+        End
+------------------------------------------------------------------
+
+# Unsetting /x also unsets /xx
+
+/[a b](?xx: [ 12 ] (?-x:[ 34 ]) )y z/B
+------------------------------------------------------------------
+        Bra
+        [ ab]
+        Bra
+        [12]
+        Bra
+        [ 34]
+        Ket
+        Ket
+        y z
+        Ket
+        End
+------------------------------------------------------------------
+
 # End of testinput2 
 Error -64: PCRE2_ERROR_BADDATA (unknown error number)
 Error -62: bad serialized data
diff --git a/testdata/testoutput8-16-2 b/testdata/testoutput8-16-2
index 02b6dfc..47c9e56 100644
--- a/testdata/testoutput8-16-2
+++ b/testdata/testoutput8-16-2
@@ -846,7 +846,7 @@ Memory allocation (code space): 14
 /(?|(?|(?J:(?|(?x:(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|
 )))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))
 /parens_nest_limit=1000,-fullbincode
-Failed: error 184 at offset 1540: (?| and/or (?J: or (?x: parentheses are too deeply nested
+Failed: error 184 at offset 1504: (?| and/or (?J: or (?x: parentheses are too deeply nested
 
 # Use "expand" to create some very long patterns with nested parentheses, in
 # order to test workspace overflow. Again, this varies with code unit width,
@@ -854,10 +854,8 @@ Failed: error 184 at offset 1540: (?| and/or (?J: or (?x: parentheses are too de
 # with link size - hence multiple tests with different values.
 
 /(?'ABC'\[[bar](]{792}*THEN:\[A]{255}\[)]{793}/expand,-fullbincode,parens_nest_limit=1000
-Failed: error 186 at offset 5813: regular expression is too complicated
 
 /(?'ABC'\[[bar](]{793}*THEN:\[A]{255}\[)]{794}/expand,-fullbincode,parens_nest_limit=1000
-Failed: error 186 at offset 5820: regular expression is too complicated
 
 /(?'ABC'\[[bar](]{1793}*THEN:\[A]{255}\[)]{1794}/expand,-fullbincode,parens_nest_limit=2000
 Failed: error 186 at offset 12820: regular expression is too complicated
diff --git a/testdata/testoutput8-32-2 b/testdata/testoutput8-32-2
index 83e3086..30667a3 100644
--- a/testdata/testoutput8-32-2
+++ b/testdata/testoutput8-32-2
@@ -853,10 +853,8 @@ Memory allocation (code space): 28
 # with link size - hence multiple tests with different values.
 
 /(?'ABC'\[[bar](]{792}*THEN:\[A]{255}\[)]{793}/expand,-fullbincode,parens_nest_limit=1000
-Failed: error 186 at offset 5813: regular expression is too complicated
 
 /(?'ABC'\[[bar](]{793}*THEN:\[A]{255}\[)]{794}/expand,-fullbincode,parens_nest_limit=1000
-Failed: error 186 at offset 5820: regular expression is too complicated
 
 /(?'ABC'\[[bar](]{1793}*THEN:\[A]{255}\[)]{1794}/expand,-fullbincode,parens_nest_limit=2000
 Failed: error 186 at offset 12820: regular expression is too complicated
diff --git a/testdata/testoutput8-8-2 b/testdata/testoutput8-8-2
index 6dbd83a..4b03356 100644
--- a/testdata/testoutput8-8-2
+++ b/testdata/testoutput8-8-2
@@ -846,7 +846,7 @@ Memory allocation (code space): 10
 /(?|(?|(?J:(?|(?x:(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|(?|
 )))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))
 /parens_nest_limit=1000,-fullbincode
-Failed: error 184 at offset 1540: (?| and/or (?J: or (?x: parentheses are too deeply nested
+Failed: error 184 at offset 1504: (?| and/or (?J: or (?x: parentheses are too deeply nested
 
 # Use "expand" to create some very long patterns with nested parentheses, in
 # order to test workspace overflow. Again, this varies with code unit width,
@@ -856,7 +856,6 @@ Failed: error 184 at offset 1540: (?| and/or (?J: or (?x: parentheses are too de
 /(?'ABC'\[[bar](]{792}*THEN:\[A]{255}\[)]{793}/expand,-fullbincode,parens_nest_limit=1000
 
 /(?'ABC'\[[bar](]{793}*THEN:\[A]{255}\[)]{794}/expand,-fullbincode,parens_nest_limit=1000
-Failed: error 186 at offset 5820: regular expression is too complicated
 
 /(?'ABC'\[[bar](]{1793}*THEN:\[A]{255}\[)]{1794}/expand,-fullbincode,parens_nest_limit=2000
 Failed: error 186 at offset 12820: regular expression is too complicated