From b19614352387283e190bf7d9aecdf6ffac06caf0 Mon Sep 17 00:00:00 2001 From: "Philip.Hazel" Date: Fri, 3 Aug 2018 09:38:36 +0000 Subject: [PATCH] Make /x more Perl-compatible by recognizing all of Unicode's "Pattern White Space" characters, not just the ASCII ones. --- ChangeLog | 7 + doc/html/pcre2api.html | 59 +- doc/html/pcre2pattern.html | 36 +- doc/html/pcre2syntax.html | 4 +- doc/pcre2.txt | 2273 ++++++++++++++++++------------------ doc/pcre2api.3 | 61 +- doc/pcre2pattern.3 | 40 +- doc/pcre2syntax.3 | 6 +- src/pcre2_compile.c | 25 +- testdata/testinput1 | 2 +- testdata/testinput4 | 15 + testdata/testinput5 | 14 + testdata/testoutput1 | 2 +- testdata/testoutput4 | 18 + testdata/testoutput5 | 17 + 15 files changed, 1374 insertions(+), 1205 deletions(-) diff --git a/ChangeLog b/ChangeLog index 3aa91de..c4f682e 100644 --- a/ChangeLog +++ b/ChangeLog @@ -133,6 +133,13 @@ terminated by (*ACCEPT). 29. Add support for \N{U+dddd}, but not in EBCDIC environments. 30. Add support for (?^) for unsetting all imnsx options. + +31. The PCRE2_EXTENDED (/x) option only ever discarded space characters whose +code point was less than 256 and that were recognized by the lookup table +generated by pcre2_maketables(), which uses isspace() to identify white space. +Now, when Unicode support is compiled, PCRE2_EXTENDED also discards U+0085, +U+200E, U+200F, U+2028, and U+2029, which are additional characters defined by +Unicode as "Pattern White Space". This makes PCRE2 compatible with Perl. Version 10.31 12-February-2018 diff --git a/doc/html/pcre2api.html b/doc/html/pcre2api.html index 8e3f119..5586c6a 100644 --- a/doc/html/pcre2api.html +++ b/doc/html/pcre2api.html @@ -837,10 +837,10 @@ page for details.

When a pattern is compiled with the PCRE2_EXTENDED or PCRE2_EXTENDED_MORE -option, the newline convention affects the recognition of white space and the -end of internal comments starting with #. The value is saved with the compiled -pattern for subsequent use by the JIT compiler and by the two interpreted -matching functions, pcre2_match() and pcre2_dfa_match(). +option, the newline convention affects the recognition of the end of internal +comments starting with #. The value is saved with the compiled pattern for +subsequent use by the JIT compiler and by the two interpreted matching +functions, pcre2_match() and pcre2_dfa_match().

int pcre2_set_parens_nest_limit(pcre2_compile_context *ccontext, @@ -1424,9 +1424,9 @@ include a closing parenthesis in the name. However, if the PCRE2_ALT_VERBNAMES option is set, normal backslash processing is applied to verb names and only an unescaped closing parenthesis terminates the name. A closing parenthesis can be included in a name either as \) or between \Q and \E. If the PCRE2_EXTENDED -or PCRE2_EXTENDED_MORE option is set, unescaped whitespace in verb names is -skipped and #-comments are recognized in this mode, exactly as in the rest of -the pattern. +or PCRE2_EXTENDED_MORE option is set with PCRE2_ALT_VERBNAMES, unescaped +whitespace in verb names is skipped and #-comments are recognized, exactly as +in the rest of the pattern. 

   PCRE2_AUTO_CALLOUT
@@ -1510,15 +1510,36 @@ is not allowed within sequences such as (?> that introduce various parenthesized subpatterns, nor within numerical quantifiers such as {1,3}. Ignorable white space is permitted between an item and a following quantifier and between a quantifier and a following + that indicates possessiveness. +PCRE2_EXTENDED is equivalent to Perl's /x option, and it can be changed within +a pattern by a (?x) option setting.

-PCRE2_EXTENDED also causes characters between an unescaped # outside a -character class and the next newline, inclusive, to be ignored, which makes it -possible to include comments inside complicated patterns. 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. PCRE2_EXTENDED is -equivalent to Perl's /x option, and it can be changed within a pattern by a -(?x) option setting. +When PCRE2 is compiled without Unicode support, PCRE2_EXTENDED recognizes as +white space only those characters with code points less than 256 that are +flagged as white space in its low-character table. The table is normally +created by +pcre2_maketables(), +which uses the isspace() function to identify space characters. In most +ASCII environments, the relevant characters are those with code points 0x0009 +(tab), 0x000A (linefeed), 0x000B (vertical tab), 0x000C (formfeed), 0x000D +(carriage return), and 0x0020 (space). +

+

+When PCRE2 is compiled with Unicode support, in addition to these characters, +five more Unicode "Pattern White Space" characters are recognized by +PCRE2_EXTENDED. These are U+0085 (next line), U+200E (left-to-right mark), +U+200F (right-to-left mark), U+2028 (line separator), and U+2029 (paragraph +separator). This set of characters is the same as recognized by Perl's /x +option. Note that the horizontal and vertical space characters that are matched +by the \h and \v escapes in patterns are a much bigger set. +

+

+As well as ignoring most white space, PCRE2_EXTENDED also causes characters +between an unescaped # outside a character class and the next newline, +inclusive, to be ignored, which makes it possible to include comments inside +complicated patterns. 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.

Which characters are interpreted as newlines can be specified by a setting in @@ -1531,9 +1552,11 @@ built. PCRE2_EXTENDED_MORE This option has the effect of PCRE2_EXTENDED, but, in addition, unescaped space -and horizontal tab characters are 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. +and horizontal tab characters are ignored inside a character class. Note: only +these two characters are ignored, not the full set of pattern white space +characters that are ignored outside a character class. PCRE2_EXTENDED_MORE is +equivalent to Perl's /xx option, and it can be changed within a pattern by a +(?xx) option setting. 

   PCRE2_FIRSTLINE
@@ -3635,7 +3658,7 @@ Cambridge, England.


REVISION

-Last updated: 27 July 2018 +Last updated: 03 August 2018
Copyright © 1997-2018 University of Cambridge.
diff --git a/doc/html/pcre2pattern.html b/doc/html/pcre2pattern.html index 9643a82..6b217ec 100644 --- a/doc/html/pcre2pattern.html +++ b/doc/html/pcre2pattern.html @@ -1628,9 +1628,11 @@ alternative in the subpattern.
INTERNAL OPTION SETTING

The settings of the PCRE2_CASELESS, PCRE2_MULTILINE, PCRE2_DOTALL, -PCRE2_EXTENDED, PCRE2_EXTENDED_MORE, and PCRE2_NO_AUTO_CAPTURE 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 +PCRE2_EXTENDED, PCRE2_EXTENDED_MORE, and PCRE2_NO_AUTO_CAPTURE options can be +changed from within the pattern by a sequence of letters enclosed between "(?" +and ")". These options are Perl-compatible, and are described in detail in the +pcre2api +documentation. The option letters are: 

   i  for PCRE2_CASELESS
   m  for PCRE2_MULTILINE
@@ -2275,8 +2277,9 @@ unset value matches an empty string.
 Because there may be many capturing parentheses in a pattern, all digits
 following a backslash are taken as part of a potential backreference number.
 If the pattern continues with a digit character, some delimiter must be used to
-terminate the backreference. If the PCRE2_EXTENDED option is set, this can be
-white space. Otherwise, the \g{ syntax or an empty comment (see
+terminate the backreference. If the PCRE2_EXTENDED or PCRE2_EXTENDED_MORE
+option is set, this can be white space. Otherwise, the \g{ syntax or an empty
+comment (see
 "Comments"
 below) can be used.
 

@@ -2744,12 +2747,12 @@ 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 characters 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
+PCRE2_EXTENDED or PCRE2_EXTENDED_MORE 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
+characters 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
@@ -3108,10 +3111,11 @@ 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. PCRE2_EXTENDED does not
-affect verb names unless PCRE2_ALT_VERBNAMES is also set.
+and \E. In addition to backslash processing, if the PCRE2_EXTENDED or 
+PCRE2_EXTENDED_MORE 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 and PCRE2_EXTENDED_MORE do 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
@@ -3590,7 +3594,7 @@ Cambridge, England.
 

 
REVISION

 

-Last updated: 28 July 2018
+Last updated: 03 August 2018
 

 Copyright © 1997-2018 University of Cambridge.
 

diff --git a/doc/html/pcre2syntax.html b/doc/html/pcre2syntax.html
index 0f492a1..4a69c74 100644
--- a/doc/html/pcre2syntax.html
+++ b/doc/html/pcre2syntax.html
@@ -446,6 +446,8 @@ but some of them use Unicode properties if PCRE2_UCP is set. You can use
 

 
OPTION SETTING

 

+Changes of these options within a group are automatically cancelled at the end 
+of the group.
 
   (?i)            caseless
   (?J)            allow duplicate names
@@ -632,7 +634,7 @@ Cambridge, England.
 

 
REVISION

 

-Last updated: 28 July 2018
+Last updated: 01 August 2018
 

 Copyright © 1997-2018 University of Cambridge.
 

diff --git a/doc/pcre2.txt b/doc/pcre2.txt
index dd17020..b448416 100644
--- a/doc/pcre2.txt
+++ b/doc/pcre2.txt
@@ -869,10 +869,10 @@ PCRE2 CONTEXTS
 
        When   a   pattern   is   compiled   with   the    PCRE2_EXTENDED    or
        PCRE2_EXTENDED_MORE option, the newline convention affects the recogni-
-       tion of white space and the end of internal comments starting  with  #.
-       The  value is saved with the compiled pattern for subsequent use by the
-       JIT  compiler  and  by  the   two   interpreted   matching   functions,
-       pcre2_match() and pcre2_dfa_match().
+       tion of the end of internal comments starting  with  #.  The  value  is
+       saved  with the compiled pattern for subsequent use by the JIT compiler
+       and by  the  two  interpreted  matching  functions,  pcre2_match()  and
+       pcre2_dfa_match().
 
        int pcre2_set_parens_nest_limit(pcre2_compile_context *ccontext,
          uint32_t value);
@@ -1413,9 +1413,9 @@ COMPILING A PATTERN
        processing is applied to verb  names  and  only  an  unescaped  closing
        parenthesis  terminates the name. A closing parenthesis can be included
        in a name either as \) or between \Q and \E. If the  PCRE2_EXTENDED  or
-       PCRE2_EXTENDED_MORE  option  is set, unescaped whitespace in verb names
-       is skipped and #-comments are recognized in this mode,  exactly  as  in
-       the rest of the pattern.
+       PCRE2_EXTENDED_MORE  option  is set with PCRE2_ALT_VERBNAMES, unescaped
+       whitespace in verb names is  skipped  and  #-comments  are  recognized,
+       exactly as in the rest of the pattern.
 
          PCRE2_AUTO_CALLOUT
 
@@ -1498,339 +1498,360 @@ COMPILING A PATTERN
        introduce various parenthesized subpatterns, nor within numerical quan-
        tifiers  such  as {1,3}.  Ignorable white space is permitted between an
        item and a following quantifier and between a quantifier and a  follow-
-       ing + that indicates possessiveness.
+       ing  +  that indicates possessiveness.  PCRE2_EXTENDED is equivalent to
+       Perl's /x option, and it can be changed within  a  pattern  by  a  (?x)
+       option setting.
 
-       PCRE2_EXTENDED  also causes characters between an unescaped # outside a
-       character class and the next newline, inclusive, to be  ignored,  which
-       makes it possible to include comments inside complicated patterns. 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. PCRE2_EXTENDED is equivalent to Perl's /x option, and it can  be
-       changed within a pattern by a (?x) option setting.
+       When  PCRE2  is compiled without Unicode support, PCRE2_EXTENDED recog-
+       nizes as white space only those characters with code points  less  than
+       256 that are flagged as white space in its low-character table. The ta-
+       ble is normally created by pcre2_maketables(), which uses the isspace()
+       function  to identify space characters. In most ASCII environments, the
+       relevant characters are those with code  points  0x0009  (tab),  0x000A
+       (linefeed),  0x000B (vertical tab), 0x000C (formfeed), 0x000D (carriage
+       return), and 0x0020 (space).
+
+       When PCRE2 is compiled with Unicode support, in addition to these char-
+       acters,  five  more Unicode "Pattern White Space" characters are recog-
+       nized by PCRE2_EXTENDED. These are U+0085 (next line), U+200E (left-to-
+       right  mark), U+200F (right-to-left mark), U+2028 (line separator), and
+       U+2029 (paragraph separator). This set of characters  is  the  same  as
+       recognized  by  Perl's /x option. Note that the horizontal and vertical
+       space characters that are matched by the \h and \v escapes in  patterns
+       are a much bigger set.
+
+       As  well as ignoring most white space, PCRE2_EXTENDED also causes char-
+       acters between an unescaped # outside a character class  and  the  next
+       newline,  inclusive,  to be ignored, which makes it possible to include
+       comments inside complicated patterns. 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.
 
        Which characters are interpreted as newlines can be specified by a set-
-       ting in the compile context that is passed to pcre2_compile() or  by  a
-       special  sequence at the start of the pattern, as described in the sec-
-       tion entitled "Newline conventions" in the pcre2pattern  documentation.
+       ting  in  the compile context that is passed to pcre2_compile() or by a
+       special sequence at the start of the pattern, as described in the  sec-
+       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,
-       unescaped space and horizontal tab  characters  are  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  set-
+       This option  has  the  effect  of  PCRE2_EXTENDED,  but,  in  addition,
+       unescaped  space  and  horizontal  tab  characters are ignored inside a
+       character class. Note: only these two characters are ignored,  not  the
+       full  set  of pattern white space characters that are ignored outside a
+       character  class.  PCRE2_EXTENDED_MORE  is  equivalent  to  Perl's  /xx
+       option,  and  it can be changed within a pattern by a (?xx) option set-
        ting.
 
          PCRE2_FIRSTLINE
 
        If this option is set, the start of an unanchored pattern match must be
-       before or at the first newline in  the  subject  string  following  the
-       start  of  matching, though the matched text may continue over the new-
+       before  or  at  the  first  newline in the subject string following the
+       start of matching, though the matched text may continue over  the  new-
        line. If startoffset is non-zero, the limiting newline is not necessar-
-       ily  the  first  newline  in  the  subject. For example, if the subject
+       ily the first newline in the  subject.  For  example,  if  the  subject
        string is "abc\nxyz" (where \n represents a single-character newline) a
-       pattern  match for "yz" succeeds with PCRE2_FIRSTLINE if startoffset is
-       greater than 3. See also PCRE2_USE_OFFSET_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
+       pattern match for "yz" succeeds with PCRE2_FIRSTLINE if startoffset  is
+       greater  than 3. See also PCRE2_USE_OFFSET_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_LITERAL
 
        If this option is set, all meta-characters in the pattern are disabled,
-       and it is treated as a literal string. Matching literal strings with  a
+       and  it is treated as a literal string. Matching literal strings with a
        regular expression engine is not the most efficient way of doing it. If
-       you are doing a lot of literal matching and  are  worried  about  effi-
+       you  are  doing  a  lot of literal matching and are worried about effi-
        ciency, you should consider using other approaches. The only other main
        options  that  are  allowed  with  PCRE2_LITERAL  are:  PCRE2_ANCHORED,
        PCRE2_ENDANCHORED, PCRE2_AUTO_CALLOUT, PCRE2_CASELESS, PCRE2_FIRSTLINE,
        PCRE2_NO_START_OPTIMIZE,     PCRE2_NO_UTF_CHECK,     PCRE2_UTF,     and
-       PCRE2_USE_OFFSET_LIMIT.  The  extra  options PCRE2_EXTRA_MATCH_LINE and
-       PCRE2_EXTRA_MATCH_WORD are also supported. Any other options  cause  an
+       PCRE2_USE_OFFSET_LIMIT. The extra  options  PCRE2_EXTRA_MATCH_LINE  and
+       PCRE2_EXTRA_MATCH_WORD  are  also supported. Any other options cause an
        error.
 
          PCRE2_MATCH_UNSET_BACKREF
 
-       If  this  option  is  set, a backreference 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 backreference 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
+       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). This
-       is the same as Perl's /n option.  Note that, when this option  is  set,
-       references  to capturing groups (backreferences or recursion/subroutine
-       calls) may only refer to named groups, though the reference can  be  by
+       is  the  same as Perl's /n option.  Note that, when this option is set,
+       references to capturing groups (backreferences 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 backrefer-
-       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  backrefer-
+       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 code unit value,
-       the matching code searches the subject for that value, 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  code  unit  value,
+       the  matching code searches the subject for that value, 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
+       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 a valid UTF string, 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
+       If you know that your pattern is a valid UTF string, 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 pattern 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 UTF  validity  checking  of  the  subject
+       pcre_dfa_match(),  to  suppress  UTF  validity  checking of the subject
        string.
 
        Note also that setting PCRE2_NO_UTF_CHECK at compile time does not dis-
-       able the error that is given if an escape sequence for an invalid  Uni-
-       code  code  point is encountered in the pattern. In particular, the so-
-       called "surrogate" code points (0xd800 to 0xdfff) are invalid.  If  you
-       want  to  allow  escape  sequences  such  as  \x{d800}  you can set the
-       PCRE2_EXTRA_ALLOW_SURROGATE_ESCAPES extra option, as described  in  the
-       section  entitled "Extra compile options" below.  However, this is pos-
+       able  the error that is given if an escape sequence for an invalid Uni-
+       code code point is encountered in the pattern. In particular,  the  so-
+       called  "surrogate"  code points (0xd800 to 0xdfff) are invalid. If you
+       want to allow escape  sequences  such  as  \x{d800}  you  can  set  the
+       PCRE2_EXTRA_ALLOW_SURROGATE_ESCAPES  extra  option, as described in the
+       section entitled "Extra compile options" below.  However, this is  pos-
        sible only in UTF-8 and UTF-32 modes, because these values are not rep-
        resentable in UTF-16.
 
          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  PCRE2_UTF 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 PCRE2_UTF changes the behaviour of PCRE2  are  given  in
        the pcre2unicode page.
 
    Extra compile options
 
-       Unlike the main compile-time options, the extra options are  not  saved
+       Unlike  the  main compile-time options, the extra options are not saved
        with the compiled pattern. The option bits that can be set in a compile
-       context by calling the pcre2_set_compile_extra_options()  function  are
+       context  by  calling the pcre2_set_compile_extra_options() function are
        as follows:
 
          PCRE2_EXTRA_ALLOW_SURROGATE_ESCAPES
 
-       This  option  applies when compiling a pattern in UTF-8 or UTF-32 mode.
-       It is forbidden in UTF-16 mode, and ignored in non-UTF  modes.  Unicode
+       This option applies when compiling a pattern in UTF-8 or  UTF-32  mode.
+       It  is  forbidden in UTF-16 mode, and ignored in non-UTF modes. Unicode
        "surrogate" code points in the range 0xd800 to 0xdfff are used in pairs
-       in UTF-16 to encode code points with values in  the  range  0x10000  to
-       0x10ffff.  The  surrogates  cannot  therefore be represented in UTF-16.
+       in  UTF-16  to  encode  code points with values in the range 0x10000 to
+       0x10ffff. The surrogates cannot therefore  be  represented  in  UTF-16.
        They can be represented in UTF-8 and UTF-32, but are defined as invalid
-       code  points,  and  cause  errors  if  encountered in a UTF-8 or UTF-32
+       code points, and cause errors if  encountered  in  a  UTF-8  or  UTF-32
        string that is being checked for validity by PCRE2.
 
-       These values also cause errors if encountered in escape sequences  such
+       These  values also cause errors if encountered in escape sequences such
        as \x{d912} within a pattern. However, it seems that some applications,
-       when using PCRE2 to check for unwanted  characters  in  UTF-8  strings,
-       explicitly   test  for  the  surrogates  using  escape  sequences.  The
-       PCRE2_NO_UTF_CHECK option does  not  disable  the  error  that  occurs,
-       because  it applies only to the testing of input strings for UTF valid-
+       when  using  PCRE2  to  check for unwanted characters in UTF-8 strings,
+       explicitly  test  for  the  surrogates  using  escape  sequences.   The
+       PCRE2_NO_UTF_CHECK  option  does  not  disable  the  error that occurs,
+       because it applies only to the testing of input strings for UTF  valid-
        ity.
 
-       If the extra option PCRE2_EXTRA_ALLOW_SURROGATE_ESCAPES is set,  surro-
-       gate  code  point values in UTF-8 and UTF-32 patterns no longer provoke
-       errors and are incorporated in the compiled pattern. However, they  can
-       only  match  subject characters if the matching function is called with
+       If  the extra option PCRE2_EXTRA_ALLOW_SURROGATE_ESCAPES is set, surro-
+       gate code point values in UTF-8 and UTF-32 patterns no  longer  provoke
+       errors  and are incorporated in the compiled pattern. However, they can
+       only match subject characters if the matching function is  called  with
        PCRE2_NO_UTF_CHECK set.
 
          PCRE2_EXTRA_BAD_ESCAPE_IS_LITERAL
 
-       This is a dangerous option. Use with care. By default, an  unrecognized
-       escape  such  as \j or a malformed one such as \x{2z} causes a compile-
+       This  is a dangerous option. Use with care. By default, an unrecognized
+       escape such as \j or a malformed one such as \x{2z} causes  a  compile-
        time error when detected by pcre2_compile(). Perl is somewhat inconsis-
-       tent  in  handling  such items: for example, \j is treated as a literal
-       "j", and non-hexadecimal digits in \x{} are just ignored, though  warn-
-       ings  are given in both cases if Perl's warning switch is enabled. How-
-       ever, a malformed octal number after \o{  always  causes  an  error  in
+       tent in handling such items: for example, \j is treated  as  a  literal
+       "j",  and non-hexadecimal digits in \x{} are just ignored, though warn-
+       ings are given in both cases if Perl's warning switch is enabled.  How-
+       ever,  a  malformed  octal  number  after \o{ always causes an error in
        Perl.
 
-       If  the  PCRE2_EXTRA_BAD_ESCAPE_IS_LITERAL  extra  option  is passed to
-       pcre2_compile(), all unrecognized or  erroneous  escape  sequences  are
-       treated  as  single-character escapes. For example, \j is a literal "j"
-       and \x{2z} is treated as  the  literal  string  "x{2z}".  Setting  this
-       option  means  that  typos in patterns may go undetected and have unex-
+       If the PCRE2_EXTRA_BAD_ESCAPE_IS_LITERAL  extra  option  is  passed  to
+       pcre2_compile(),  all  unrecognized  or  erroneous escape sequences are
+       treated as single-character escapes. For example, \j is a  literal  "j"
+       and  \x{2z}  is  treated  as  the  literal string "x{2z}". Setting this
+       option means that typos in patterns may go undetected  and  have  unex-
        pected results. This is a dangerous option. Use with care.
 
          PCRE2_EXTRA_MATCH_LINE
 
-       This option is provided for use by  the  -x  option  of  pcre2grep.  It
-       causes  the  pattern  only to match complete lines. This is achieved by
-       automatically inserting the code for "^(?:" at the start  of  the  com-
-       piled  pattern  and ")$" at the end. Thus, when PCRE2_MULTILINE is set,
-       the matched line may be in the  middle  of  the  subject  string.  This
+       This  option  is  provided  for  use  by the -x option of pcre2grep. It
+       causes the pattern only to match complete lines. This  is  achieved  by
+       automatically  inserting  the  code for "^(?:" at the start of the com-
+       piled pattern and ")$" at the end. Thus, when PCRE2_MULTILINE  is  set,
+       the  matched  line  may  be  in  the middle of the subject string. This
        option can be used with PCRE2_LITERAL.
 
          PCRE2_EXTRA_MATCH_WORD
 
-       This  option  is  provided  for  use  by the -w option of pcre2grep. It
-       causes the pattern only to match strings that have a word  boundary  at
-       the  start and the end. This is achieved by automatically inserting the
-       code for "\b(?:" at the start of the compiled pattern and ")\b" at  the
-       end.  The option may be used with PCRE2_LITERAL. However, it is ignored
+       This option is provided for use by  the  -w  option  of  pcre2grep.  It
+       causes  the  pattern only to match strings that have a word boundary at
+       the start and the end. This is achieved by automatically inserting  the
+       code  for "\b(?:" at the start of the compiled pattern and ")\b" at the
+       end. The option may be used with PCRE2_LITERAL. However, it is  ignored
        if PCRE2_EXTRA_MATCH_LINE is also set.
 
 
@@ -1853,53 +1874,53 @@ 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");
@@ -1908,15 +1929,15 @@ 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.
 
 
@@ -1924,13 +1945,13 @@ 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:
@@ -1940,9 +1961,9 @@ 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;
@@ -1960,22 +1981,22 @@ INFORMATION ABOUT A COMPILED PATTERN
          PCRE2_INFO_EXTRAOPTIONS
 
        Return copies 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)
-       option settings such as (*UTF) at the  start  of  the  pattern  itself.
-       PCRE2_INFO_EXTRAOPTIONS  returns the extra options that were set in the
-       compile context by calling the pcre2_set_compile_extra_options()  func-
+       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.
+       PCRE2_INFO_EXTRAOPTIONS returns the extra options that were set in  the
+       compile  context by calling the pcre2_set_compile_extra_options() func-
        tion.
 
-       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:
 
@@ -1984,7 +2005,7 @@ 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
@@ -1994,94 +2015,94 @@ 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  backreference  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
-       backreference.   Backreferences such as \4 or \g{12} match the captured
-       characters of the given group, but in addition, the check that  a  cap-
-       turing  group  is  set in a conditional subpattern such as (?(3)a|b) is
+       Return  the  number  of  the  highest backreference 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
+       backreference.  Backreferences such as \4 or \g{12} match the  captured
+       characters  of  the given group, but in addition, the check that a cap-
+       turing group is set in a conditional subpattern such  as  (?(3)a|b)  is
        also a backreference. Zero is returned if there are no backreferences.
 
          PCRE2_INFO_BSR
 
-       The output is a uint32_t integer 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
+       The  output  is a uint32_t integer 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_ANYCRLF 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
+       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 a uint32_t integer. If no such value has
-       been  set,  the  call  to  pcre2_pattern_info()   returns   the   error
+       been   set,   the   call  to  pcre2_pattern_info()  returns  the  error
        PCRE2_ERROR_UNSET. Note that this limit will only be used during match-
-       ing if it is less than the limit set or defaulted by the caller of  the
+       ing  if it is less than the limit set or defaulted by the caller of the
        match function.
 
          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 a 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"
-       from  a  pattern such as (cat|cow|coyote), 1 is returned, and the 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.
+       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  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 for a
-       pattern 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
+       Return the value of the first code unit of any  matched  string  for  a
+       pattern  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
        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 a size_t
+       backtracking  positions  when the pattern is processed by pcre2_match()
+       without the use of JIT. The third argument should  point  to  a  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
@@ -2089,81 +2110,81 @@ INFORMATION ABOUT A COMPILED PATTERN
        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 a uint32_t integer. If no such value has been set,
-       the call to pcre2_pattern_info() returns the  error  PCRE2_ERROR_UNSET.
-       Note  that  this  limit will only be used during matching if it is less
+       the  call  to pcre2_pattern_info() returns the error PCRE2_ERROR_UNSET.
+       Note that this limit will only be used during matching if  it  is  less
        than the limit set or defaulted by the caller of the match function.
 
          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 code unit that must exist in
-       any matched string, other than  at  its  start,  for  a  pattern  where
+       Return the value of the rightmost literal code unit that must exist  in
+       any  matched  string,  other  than  at  its  start, for a pattern where
        PCRE2_INFO_LASTCODETYPE returns 1. Otherwise, return 0. The third argu-
        ment should point to an uint32_t variable.
 
          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 a uint32_t 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 a uint32_t integer. If no such value has been
+       set,   the   call   to   pcre2_pattern_info()   returns    the    error
        PCRE2_ERROR_UNSET. Note that this limit will only be used during match-
-       ing  if it is less than the limit set or defaulted by the caller of the
+       ing if it is less than the limit set or defaulted by the caller of  the
        match function.
 
          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 a
-       uint32_t integer. This information is useful when  doing  multi-segment
-       matching  using  the  partial matching facilities. Note that the simple
+       hind assertion in the pattern. The third argument  should  point  to  a
+       uint32_t  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 regis-
-       ters  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 processed. Oth-
-       erwise, if there are no lookbehinds in  the  pattern,  \A  might  match
+       ters 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 processed.  Oth-
+       erwise,  if  there  are  no  lookbehinds in the pattern, \A might match
        incorrectly at the start of a second or subsequent 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
@@ -2171,50 +2192,50 @@ 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 ??:
 
@@ -2223,8 +2244,8 @@ 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
@@ -2243,14 +2264,14 @@ 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.
 
 
@@ -2261,30 +2282,30 @@ 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  host  on
-       which  the  patterns  are  reloaded must be running the same version of
+       It is possible to save compiled patterns  on  disc  or  elsewhere,  and
+       reload  them  later,  subject  to a number of restrictions. 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 endi-
-       anness,  pointer  width,  and PCRE2_SIZE type. Before compiled patterns
-       can be saved, they must be converted to a "serialized" form,  which  in
-       the  case of PCRE2 is really just a bytecode dump.  The functions whose
-       names begin with pcre2_serialize_ are used for converting to  and  from
-       the  serialized form. They are described in the pcre2serialize documen-
-       tation. Note that PCRE2 serialization does not  convert  compiled  pat-
+       anness, pointer width, and PCRE2_SIZE type.  Before  compiled  patterns
+       can  be  saved, they must be converted to a "serialized" form, which in
+       the case of PCRE2 is really just a bytecode dump.  The functions  whose
+       names  begin  with pcre2_serialize_ are used for converting to and from
+       the serialized form. They are described in the pcre2serialize  documen-
+       tation.  Note  that  PCRE2 serialization does not convert compiled pat-
        terns to an abstract format like Java or .NET serialization.
 
 
@@ -2298,57 +2319,57 @@ 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
-       by  calling  pcre2_match_data_free(). If this function is called with a
+       When  a match data block itself is no longer needed, it should be freed
+       by calling pcre2_match_data_free(). If this function is called  with  a
        NULL argument, it returns immediately, without doing anything.
 
 
@@ -2359,15 +2380,15 @@ 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():
@@ -2382,187 +2403,187 @@ MATCHING A PATTERN: THE TRADITIONAL FUNCTION
            md,             /* 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 zeros.
 
-       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, a
        single attempt to match at the given offset is made. This can only suc-
-       ceed 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
+       ceed  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
        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.
 
@@ -2572,38 +2593,38 @@ 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.
 
@@ -2614,81 +2635,81 @@ 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.
 
 
@@ -2698,69 +2719,69 @@ 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
+       After  a  successful match, a partial match (PCRE2_ERROR_PARTIAL), or a
        failure to match (PCRE2_ERROR_NOMATCH), a (*MARK), (*PRUNE), or (*THEN)
-       name may be available. The function pcre2_get_mark() can be  called  to
-       access  this  name.  The  same  function applies to all three verbs. It
+       name  may  be available. The function pcre2_get_mark() can be called to
+       access this name. The same function applies  to  all  three  verbs.  It
        returns a pointer to the zero-terminated name, which is within the com-
        piled pattern. If no name is available, NULL is returned. The length of
-       the name (excluding the terminating zero) is stored in  the  code  unit
-       that  precedes  the name. You should use this length instead of relying
+       the  name  (excluding  the terminating zero) is stored in the code unit
+       that precedes the name. You should use this length instead  of  relying
        on the terminating zero if the name might contain a binary zero.
 
-       After a successful match,  the  name  that  is  returned  is  the  last
-       (*MARK),  (*PRUNE),  or  (*THEN)  name encountered on the matching path
-       through the pattern.  Instances of (*PRUNE) and (*THEN)  without  names
-       are   ignored.  Thus,  for  example,  if  the  matching  path  contains
-       (*MARK:A)(*PRUNE), the name "A" is returned.  After a "no match"  or  a
-       partial  match,  the  last  encountered name is returned.  For example,
+       After  a  successful  match,  the  name  that  is  returned is the last
+       (*MARK), (*PRUNE), or (*THEN) name encountered  on  the  matching  path
+       through  the  pattern.  Instances of (*PRUNE) and (*THEN) without names
+       are  ignored.  Thus,  for  example,  if  the  matching  path   contains
+       (*MARK:A)(*PRUNE),  the  name "A" is returned.  After a "no match" or a
+       partial match, the last encountered name  is  returned.   For  example,
        consider this pattern:
 
          ^(*MARK:A)((*MARK:B)a|b)c
 
-       When it matches "bc", the returned name 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 name 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
        name is B.
 
-       Warning:  By  default, certain start-of-match optimizations are used to
-       give a fast "no match" result in some situations. For example,  if  the
-       anchoring  is removed from the pattern above, there is an initial check
-       for the presence of "c" in the  subject  before  running  the  matching
+       Warning: By default, certain start-of-match optimizations are  used  to
+       give  a  fast "no match" result in some situations. For example, if the
+       anchoring is removed from the pattern above, there is an initial  check
+       for  the  presence  of  "c"  in the subject before running the matching
        engine. This check fails for "bx", causing a match failure without see-
        ing any marks. You can disable the start-of-match optimizations by set-
        ting the PCRE2_NO_START_OPTIMIZE option for pcre2_compile() or starting
        the pattern with (*NO_START_OPT).
 
-       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
@@ -2769,20 +2790,20 @@ 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
@@ -2796,15 +2817,15 @@ 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
@@ -2817,14 +2838,14 @@ 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
@@ -2833,10 +2854,10 @@ 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
@@ -2845,12 +2866,12 @@ 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.
 
 
@@ -2859,20 +2880,20 @@ 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.
 
 
@@ -2891,39 +2912,39 @@ 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
@@ -2932,25 +2953,25 @@ 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
@@ -2961,8 +2982,8 @@ 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.
 
 
@@ -2973,32 +2994,32 @@ 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().
 
 
@@ -3018,39 +3039,39 @@ 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.
 
 
@@ -3063,83 +3084,83 @@ 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
-       before  it  starts are not supported, and give rise to an error return.
+       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.
        For global replacements, matches in which \K in a lookbehind causes the
-       match  to start earlier than the point that was reached in the previous
+       match to start earlier than the point that was reached in the  previous
        iteration are also not supported.
 
-       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),
-       (*PRUNE), or (*THEN) items in the  pattern.  The  following  forms  are
+       ify the insertion of  characters  from  capturing  groups  or  (*MARK),
+       (*PRUNE),  or  (*THEN)  items  in  the pattern. The following forms are
        always recognized:
 
          $$                  insert a dollar character
          $ or ${}      insert the contents of group 
          $*MARK or ${*MARK}  insert a (*MARK), (*PRUNE), or (*THEN) name
 
-       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+=".
 
        $*MARK inserts the name from the last encountered (*MARK), (*PRUNE), or
-       (*THEN)  on  the  matching  path  that  has a name. (*MARK) must always
-       include a name, but (*PRUNE) and (*THEN) need not. For example, in  the
-       case   of   (*MARK:A)(*PRUNE)   the  name  inserted  is  "A",  but  for
-       (*MARK:A)(*PRUNE:B) the relevant name is "B".   This  facility  can  be
-       used  to  perform  simple simultaneous substitutions, as this pcre2test
+       (*THEN) on the matching path that  has  a  name.  (*MARK)  must  always
+       include  a name, but (*PRUNE) and (*THEN) need not. For example, in the
+       case  of  (*MARK:A)(*PRUNE)  the  name  inserted  is   "A",   but   for
+       (*MARK:A)(*PRUNE:B)  the  relevant  name  is "B".  This facility can be
+       used to perform simple simultaneous substitutions,  as  this  pcre2test
        example shows:
 
          /(*MARK:pear)apple|(*MARK:orange)lemon/g,replace=${*MARK}
              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 of pcre2_substitute().
 
        PCRE2_SUBSTITUTE_GLOBAL causes the function to iterate over the subject
-       string, replacing every matching substring. If this option is not  set,
-       only  the  first matching substring is replaced. The search for matches
-       takes place in the original subject string (that is, previous  replace-
-       ments  do  not  affect  it).  Iteration is implemented by advancing the
-       startoffset value for each search, which is always  passed  the  entire
+       string,  replacing every matching substring. If this option is not set,
+       only the first matching substring is replaced. The search  for  matches
+       takes  place in the original subject string (that is, previous replace-
+       ments do not affect it).  Iteration is  implemented  by  advancing  the
+       startoffset  value  for  each search, which is always passed the entire
        subject string. If an offset limit is set in the match context, search-
        ing stops when that limit is reached.
 
-       You can restrict the effect of a global substitution to  a  portion  of
+       You  can  restrict  the effect of a global substitution to a portion of
        the subject string by setting either or both of startoffset and an off-
        set limit. Here is a pcre2test example:
 
@@ -3147,87 +3168,87 @@ CREATING A NEW STRING WITH SUBSTITUTIONS
          ABC ABC ABC ABC\=offset=3,offset_limit=12
           2: ABC A!C A!C ABC
 
-       When continuing with global substitutions after  matching  a  substring
+       When  continuing  with  global substitutions after matching a substring
        with zero length, an attempt to find a non-empty match at the same off-
        set is performed.  If this is not successful, the offset 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 offset is advanced by  two
+       two  characters are CR, LF. In this case, the offset 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
@@ -3236,42 +3257,42 @@ 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-
-       MISSINGBRACE (closing curly bracket not found),  PCRE2_ERROR_BADSUBSTI-
+       PCRE2_ERROR_BADREPESCAPE (invalid  escape  sequence),  PCRE2_ERROR_REP-
+       MISSINGBRACE  (closing curly bracket not found), PCRE2_ERROR_BADSUBSTI-
        TUTION   (syntax   error   in   extended   group   substitution),   and
-       PCRE2_ERROR_BADSUBSPATTERN (the pattern match ended before  it  started
-       or  the match started earlier than the current position in the subject,
+       PCRE2_ERROR_BADSUBSPATTERN  (the  pattern match ended before it started
+       or the match started earlier than the current position in the  subject,
        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).
 
 
@@ -3280,56 +3301,56 @@ 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.
 
 
@@ -3341,26 +3362,26 @@ 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():
@@ -3380,45 +3401,45 @@ 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.
 
@@ -3426,8 +3447,8 @@ 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
 
          <.*>
@@ -3442,73 +3463,73 @@ 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.
 
-       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 such 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  such  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 backreference.
 
          PCRE2_ERROR_DFA_UCOND
 
-       This return is given if pcre2_dfa_match() encounters a  condition  item
+       This  return  is given if pcre2_dfa_match() encounters a condition item
        that uses a backreference 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).
 
 
@@ -3521,7 +3542,7 @@ AUTHOR
 
 REVISION
 
-       Last updated: 27 July 2018
+       Last updated: 03 August 2018
        Copyright (c) 1997-2018 University of Cambridge.
 ------------------------------------------------------------------------------
  
@@ -7192,9 +7213,10 @@ INTERNAL OPTION SETTING
 
        The settings  of  the  PCRE2_CASELESS,  PCRE2_MULTILINE,  PCRE2_DOTALL,
        PCRE2_EXTENDED,  PCRE2_EXTENDED_MORE, and PCRE2_NO_AUTO_CAPTURE 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
+       can be changed from  within  the  pattern  by  a  sequence  of  letters
+       enclosed  between "(?"  and ")". These options are Perl-compatible, and
+       are described in detail in the pcre2api documentation. The option  let-
+       ters are:
 
          i  for PCRE2_CASELESS
          m  for PCRE2_MULTILINE
@@ -7204,49 +7226,49 @@ INTERNAL OPTION SETTING
          xx for PCRE2_EXTENDED_MORE
 
        For example, (?im) sets caseless, multiline matching. It is also possi-
-       ble  to  unset  these  options by preceding the relevant letters with a
+       ble to unset these options by preceding the  relevant  letters  with  a
        hyphen, for example (?-im). The two "extended" options are not indepen-
        dent; 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. Only one hyphen may appear in the
-       options string. If a letter appears both before and after  the  hyphen,
-       the  option  is unset. An empty options setting "(?)" is allowed. Need-
+       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. Only one hyphen may  appear  in  the
+       options  string.  If a letter appears both before and after the hyphen,
+       the option is unset. An empty options setting "(?)" is  allowed.  Need-
        less to say, it has no effect.
 
-       If the first character following (? is a circumflex, it causes  all  of
-       the  above  options to be unset. Thus, (?^) is equivalent to (?-imnsx).
-       Letters may follow the circumflex to  cause  some  options  to  be  re-
+       If  the  first character following (? is a circumflex, it causes all of
+       the above options to be unset. Thus, (?^) is equivalent  to  (?-imnsx).
+       Letters  may  follow  the  circumflex  to  cause some options to be re-
        instated, but a hyphen may not appear.
 
-       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. However, these are not unset by (?^).
 
-       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)
@@ -7254,14 +7276,14 @@ 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.
 
@@ -7275,18 +7297,18 @@ 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))
@@ -7294,12 +7316,12 @@ 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))
@@ -7307,37 +7329,37 @@ 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.
 
@@ -7345,14 +7367,14 @@ DUPLICATE SUBPATTERN NUMBERS
          / ( a )  (?| x ( y ) z | (p (q) r) | (t) u (v) ) ( z ) /x
          # 1            2         2  3        2     3     4
 
-       A backreference to a numbered subpattern uses  the  most  recent  value
-       that  is  set  for that number by any subpattern. The following pattern
+       A  backreference  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)/
@@ -7360,47 +7382,47 @@ 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
+       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
+       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)?|
@@ -7409,18 +7431,18 @@ 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 backreference to a non-unique named subpattern from else-
-       where  in  the  pattern,  the  subpatterns to which the name refers are
-       checked in the order in which they appear in the overall  pattern.  The
+       where 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":
 
@@ -7428,29 +7450,29 @@ 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
@@ -7464,17 +7486,17 @@ 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,}
@@ -7483,50 +7505,50 @@ 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
 
          /\*.*\*/
@@ -7535,19 +7557,19 @@ 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
@@ -7556,45 +7578,45 @@ 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.
-       When  .*   is  inside  capturing  parentheses that are the subject of a
-       backreference elsewhere in the pattern, a match at the start  may  fail
+       However,  there  are  some cases where the optimization cannot be used.
+       When .*  is inside capturing parentheses that  are  the  subject  of  a
+       backreference  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-
@@ -7603,8 +7625,8 @@ 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))+
@@ -7614,53 +7636,53 @@ 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
@@ -7670,46 +7692,46 @@ 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+>)*[!?]
@@ -7720,29 +7742,29 @@ ATOMIC GROUPING AND POSSESSIVE QUANTIFIERS
 BACKREFERENCES
 
        Outside a character class, a backslash followed by a digit greater than
-       0  (and possibly further digits) is a backreference to a capturing sub-
-       pattern earlier (that is, to its left) in the pattern,  provided  there
+       0 (and possibly further digits) is a backreference to a capturing  sub-
+       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 backreference, 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 backreference, 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  backreference"  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 backreference" 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 backreference to any
+       details  of  the  handling of digits following a backslash. There is no
+       such problem when named parentheses are used. A  backreference  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:
 
@@ -7750,46 +7772,46 @@ BACKREFERENCES
          (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 backreference matches whatever actually matched the capturing subpat-
-       tern in the current subject string, rather than anything  matching  the
-       subpattern  itself (see "Subpatterns as subroutines" below for a way of
+       tern  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 backreference, 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 backreference, 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  backreferences  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  backreference syntax, in which \g can be used for both numeric
-       and named references, is also supported. We  could  rewrite  the  above
+       There  are  several  different  ways of writing backreferences 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 backreference syntax, in which \g can be used for both  numeric
+       and  named  references,  is  also supported. We could rewrite the above
        example in any of the following ways:
 
          (?(?i)rah)\s+\k
@@ -7797,25 +7819,26 @@ BACKREFERENCES
          (?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 backreference to the same subpattern.  If  a
-       subpattern  has not actually been used in a particular match, any back-
+       There  may  be more than one backreference 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
+       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 backref-
        erence 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 backrefer-
-       ence number.  If the pattern continues with  a  digit  character,  some
-       delimiter   must  be  used  to  terminate  the  backreference.  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.
+       Because  there may be many capturing parentheses in a pattern, all dig-
+       its following a backslash are taken as part of a  potential  backrefer-
+       ence  number.   If  the  pattern continues with a digit character, some
+       delimiter  must  be  used  to  terminate  the  backreference.  If   the
+       PCRE2_EXTENDED  or PCRE2_EXTENDED_MORE option is set, this can be white
+       space. Otherwise, the \g{ syntax or an empty  comment  (see  "Comments"
+       below) can be used.
 
    Recursive backreferences
 
@@ -8245,17 +8268,17 @@ COMMENTS
 
        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:
+       PCRE2_EXTENDED or PCRE2_EXTENDED_MORE 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 characters 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 "New-
+       line 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 sin-
+       gle linefeed character) is in force:
 
          abc #comment \n still comment
 
@@ -8602,10 +8625,10 @@ BACKTRACKING CONTROL
 
        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.
-       PCRE2_EXTENDED does not affect verb names unless PCRE2_ALT_VERBNAMES is
-       also set.
+       or PCRE2_EXTENDED_MORE 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 and PCRE2_EXTENDED_MORE do 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
@@ -9049,7 +9072,7 @@ AUTHOR
 
 REVISION
 
-       Last updated: 28 July 2018
+       Last updated: 03 August 2018
        Copyright (c) 1997-2018 University of Cambridge.
 ------------------------------------------------------------------------------
  
@@ -10151,6 +10174,8 @@ COMMENT
 
 
 OPTION SETTING
+       Changes of these options within a group are automatically cancelled  at
+       the end of the group.
 
          (?i)            caseless
          (?J)            allow duplicate names
@@ -10163,14 +10188,14 @@ OPTION SETTING
          (?-...)         unset option(s)
          (?^)            unset imnsx options
 
-       Unsetting x or xx unsets both. Several options may be set at once,  and
+       Unsetting  x or xx unsets both. Several options may be set at once, and
        a mixture of setting and unsetting such as (?i-x) is allowed, but there
        may be only one hyphen. Setting (but no unsetting) is allowed after (?^
        for example (?^in). An option setting may appear at the start of a non-
        capturing group, for example (?i:...).
 
-       The following are recognized only at the very start  of  a  pattern  or
-       after  one  of the newline or \R options with similar syntax. More than
+       The  following  are  recognized  only at the very start of a pattern or
+       after one of the newline or \R options with similar syntax.  More  than
        one of them may appear. For the first three, d is a decimal number.
 
          (*LIMIT_DEPTH=d) set the backtracking limit to d
@@ -10185,17 +10210,17 @@ OPTION SETTING
          (*UTF)          set appropriate UTF mode for the library in use
          (*UCP)          set PCRE2_UCP (use Unicode properties for \d etc)
 
-       Note that LIMIT_DEPTH, LIMIT_HEAP, and LIMIT_MATCH can only reduce  the
-       value   of   the   limits   set  by  the  caller  of  pcre2_match()  or
-       pcre2_dfa_match(), not increase them. LIMIT_RECURSION  is  an  obsolete
+       Note  that LIMIT_DEPTH, LIMIT_HEAP, and LIMIT_MATCH can only reduce the
+       value  of  the  limits  set  by  the   caller   of   pcre2_match()   or
+       pcre2_dfa_match(),  not  increase  them. LIMIT_RECURSION is an obsolete
        synonym for LIMIT_DEPTH. The application can lock out the use of (*UTF)
-       and (*UCP) by setting the PCRE2_NEVER_UTF or  PCRE2_NEVER_UCP  options,
+       and  (*UCP)  by setting the PCRE2_NEVER_UTF or PCRE2_NEVER_UCP options,
        respectively, at compile time.
 
 
 NEWLINE CONVENTION
 
-       These  are  recognized  only  at the very start of the pattern or after
+       These are recognized only at the very start of  the  pattern  or  after
        option settings with a similar syntax.
 
          (*CR)           carriage return only
@@ -10208,7 +10233,7 @@ NEWLINE CONVENTION
 
 WHAT \R MATCHES
 
-       These are recognized only at the very start of  the  pattern  or  after
+       These  are  recognized  only  at the very start of the pattern or after
        option setting with a similar syntax.
 
          (*BSR_ANYCRLF)  CR, LF, or CRLF
@@ -10277,16 +10302,16 @@ CONDITIONAL PATTERNS
          (?(VERSION[>]=n.m)  test PCRE2 version
          (?(assert)          assertion condition
 
-       Note  the  ambiguity of (?(R) and (?(Rn) which might be named reference
-       conditions or recursion tests. Such a condition  is  interpreted  as  a
+       Note the ambiguity of (?(R) and (?(Rn) which might be  named  reference
+       conditions  or  recursion  tests.  Such a condition is interpreted as a
        reference condition if the relevant named group exists.
 
 
 BACKTRACKING CONTROL
 
-       All  backtracking  control  verbs  may be in the form (*VERB:NAME). For
-       (*MARK) the name is mandatory, for the others it is  optional.  (*SKIP)
-       changes  its  behaviour if :NAME is present. The others just set a name
+       All backtracking control verbs may be in  the  form  (*VERB:NAME).  For
+       (*MARK)  the  name is mandatory, for the others it is optional. (*SKIP)
+       changes its behaviour if :NAME is present. The others just set  a  name
        for passing back to the caller, but this is not a name that (*SKIP) can
        see. The following act immediately they are reached:
 
@@ -10294,7 +10319,7 @@ BACKTRACKING CONTROL
          (*FAIL)         force backtrack; synonym (*F)
          (*MARK:NAME)    set name to be passed back; synonym (*:NAME)
 
-       The  following  act only when a subsequent match failure causes a back-
+       The following act only when a subsequent match failure causes  a  back-
        track to reach them. They all force a match failure, but they differ in
        what happens afterwards. Those that advance the start-of-match point do
        so only if the pattern is not anchored.
@@ -10306,7 +10331,7 @@ BACKTRACKING CONTROL
                          (*MARK:NAME); if not found, the (*SKIP) is ignored
          (*THEN)         local failure, backtrack to next alternation
 
-       The effect of one of these verbs in a group called as a  subroutine  is
+       The  effect  of one of these verbs in a group called as a subroutine is
        confined to the subroutine call.
 
 
@@ -10317,14 +10342,14 @@ CALLOUTS
          (?C"text")      callout with string data
 
        The allowed string delimiters are ` ' " ^ % # $ (which are the same for
-       the start and the end), and the starting delimiter { matched  with  the
-       ending  delimiter  }. To encode the ending delimiter within the string,
+       the  start  and the end), and the starting delimiter { matched with the
+       ending delimiter }. To encode the ending delimiter within  the  string,
        double it.
 
 
 SEE ALSO
 
-       pcre2pattern(3),   pcre2api(3),   pcre2callout(3),    pcre2matching(3),
+       pcre2pattern(3),    pcre2api(3),   pcre2callout(3),   pcre2matching(3),
        pcre2(3).
 
 
@@ -10337,7 +10362,7 @@ AUTHOR
 
 REVISION
 
-       Last updated: 28 July 2018
+       Last updated: 01 August 2018
        Copyright (c) 1997-2018 University of Cambridge.
 ------------------------------------------------------------------------------
  
diff --git a/doc/pcre2api.3 b/doc/pcre2api.3
index 7866a11..f13373c 100644
--- a/doc/pcre2api.3
+++ b/doc/pcre2api.3
@@ -1,4 +1,4 @@
-.TH PCRE2API 3 "27 July 2018" "PCRE2 10.32"
+.TH PCRE2API 3 "03 August 2018" "PCRE2 10.32"
 .SH NAME
 PCRE2 - Perl-compatible regular expressions (revised API)
 .sp
@@ -775,10 +775,10 @@ sequence such as (*CRLF). See the
 page for details.
 .P
 When a pattern is compiled with the PCRE2_EXTENDED or PCRE2_EXTENDED_MORE
-option, the newline convention affects the recognition of white space and the
-end of internal comments starting with #. The value is saved with the compiled
-pattern for subsequent use by the JIT compiler and by the two interpreted
-matching functions, \fIpcre2_match()\fP and \fIpcre2_dfa_match()\fP.
+option, the newline convention affects the recognition of the end of internal
+comments starting with #. The value is saved with the compiled pattern for
+subsequent use by the JIT compiler and by the two interpreted matching
+functions, \fIpcre2_match()\fP and \fIpcre2_dfa_match()\fP.
 .sp
 .nf
 .B int pcre2_set_parens_nest_limit(pcre2_compile_context *\fIccontext\fP,
@@ -1356,9 +1356,9 @@ include a closing parenthesis in the name. However, if the PCRE2_ALT_VERBNAMES
 option is set, normal backslash processing is applied to verb names and only an
 unescaped closing parenthesis terminates the name. A closing parenthesis can be
 included in a name either as \e) or between \eQ and \eE. If the PCRE2_EXTENDED
-or PCRE2_EXTENDED_MORE option is set, unescaped whitespace in verb names is
-skipped and #-comments are recognized in this mode, exactly as in the rest of
-the pattern.
+or PCRE2_EXTENDED_MORE option is set with PCRE2_ALT_VERBNAMES, unescaped
+whitespace in verb names is skipped and #-comments are recognized, exactly as
+in the rest of the pattern.
 .sp
   PCRE2_AUTO_CALLOUT
 .sp
@@ -1445,14 +1445,35 @@ is not allowed within sequences such as (?> that introduce various
 parenthesized subpatterns, nor within numerical quantifiers such as {1,3}.
 Ignorable white space is permitted between an item and a following quantifier
 and between a quantifier and a following + that indicates possessiveness.
+PCRE2_EXTENDED is equivalent to Perl's /x option, and it can be changed within
+a pattern by a (?x) option setting.
 .P
-PCRE2_EXTENDED also causes characters between an unescaped # outside a
-character class and the next newline, inclusive, to be ignored, which makes it
-possible to include comments inside complicated patterns. 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. PCRE2_EXTENDED is
-equivalent to Perl's /x option, and it can be changed within a pattern by a
-(?x) option setting.
+When PCRE2 is compiled without Unicode support, PCRE2_EXTENDED recognizes as 
+white space only those characters with code points less than 256 that are 
+flagged as white space in its low-character table. The table is normally 
+created by 
+.\" HREF
+\fBpcre2_maketables()\fP, 
+.\"
+which uses the \fBisspace()\fP function to identify space characters. In most
+ASCII environments, the relevant characters are those with code points 0x0009
+(tab), 0x000A (linefeed), 0x000B (vertical tab), 0x000C (formfeed), 0x000D
+(carriage return), and 0x0020 (space). 
+.P
+When PCRE2 is compiled with Unicode support, in addition to these characters,
+five more Unicode "Pattern White Space" characters are recognized by
+PCRE2_EXTENDED. These are U+0085 (next line), U+200E (left-to-right mark),
+U+200F (right-to-left mark), U+2028 (line separator), and U+2029 (paragraph
+separator). This set of characters is the same as recognized by Perl's /x
+option. Note that the horizontal and vertical space characters that are matched
+by the \eh and \ev escapes in patterns are a much bigger set.
+.P
+As well as ignoring most white space, PCRE2_EXTENDED also causes characters
+between an unescaped # outside a character class and the next newline,
+inclusive, to be ignored, which makes it possible to include comments inside
+complicated patterns. 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.
 .P
 Which characters are interpreted as newlines can be specified by a setting in
 the compile context that is passed to \fBpcre2_compile()\fP or by a special
@@ -1467,9 +1488,11 @@ built.
   PCRE2_EXTENDED_MORE
 .sp
 This option has the effect of PCRE2_EXTENDED, but, in addition, unescaped space
-and horizontal tab characters are 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.
+and horizontal tab characters are ignored inside a character class. Note: only 
+these two characters are ignored, not the full set of pattern white space 
+characters that are ignored outside a character class. PCRE2_EXTENDED_MORE is
+equivalent to Perl's /xx option, and it can be changed within a pattern by a
+(?xx) option setting.
 .sp
   PCRE2_FIRSTLINE
 .sp
@@ -3641,6 +3664,6 @@ Cambridge, England.
 .rs
 .sp
 .nf
-Last updated: 27 July 2018
+Last updated: 03 August 2018
 Copyright (c) 1997-2018 University of Cambridge.
 .fi
diff --git a/doc/pcre2pattern.3 b/doc/pcre2pattern.3
index a19ddd7..ea96a1d 100644
--- a/doc/pcre2pattern.3
+++ b/doc/pcre2pattern.3
@@ -1,4 +1,4 @@
-.TH PCRE2PATTERN 3 "28 July 2018" "PCRE2 10.32"
+.TH PCRE2PATTERN 3 "03 August 2018" "PCRE2 10.32"
 .SH NAME
 PCRE2 - Perl-compatible regular expressions (revised API)
 .SH "PCRE2 REGULAR EXPRESSION DETAILS"
@@ -1627,9 +1627,13 @@ alternative in the subpattern.
 .rs
 .sp
 The settings of the PCRE2_CASELESS, PCRE2_MULTILINE, PCRE2_DOTALL,
-PCRE2_EXTENDED, PCRE2_EXTENDED_MORE, and PCRE2_NO_AUTO_CAPTURE 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
+PCRE2_EXTENDED, PCRE2_EXTENDED_MORE, and PCRE2_NO_AUTO_CAPTURE options can be
+changed from within the pattern by a sequence of letters enclosed between "(?"
+and ")". These options are Perl-compatible, and are described in detail in the
+.\" HREF
+\fBpcre2api\fP
+.\"
+documentation. The option letters are:
 .sp
   i  for PCRE2_CASELESS
   m  for PCRE2_MULTILINE
@@ -2273,8 +2277,9 @@ unset value matches an empty string.
 Because there may be many capturing parentheses in a pattern, all digits
 following a backslash are taken as part of a potential backreference number.
 If the pattern continues with a digit character, some delimiter must be used to
-terminate the backreference. If the PCRE2_EXTENDED option is set, this can be
-white space. Otherwise, the \eg{ syntax or an empty comment (see
+terminate the backreference. If the PCRE2_EXTENDED or PCRE2_EXTENDED_MORE
+option is set, this can be white space. Otherwise, the \eg{ syntax or an empty
+comment (see
 .\" HTML 
 .\" 
 "Comments"
@@ -2762,12 +2767,12 @@ no part in the pattern matching.
 .P
 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 characters 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
+PCRE2_EXTENDED or PCRE2_EXTENDED_MORE 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
+characters 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
 .\" HTML 
 .\" 
 "Newline conventions"
@@ -3132,10 +3137,11 @@ only backslash items that are permitted are \eQ, \eE, and sequences such as
 are faulted.
 .P
 A closing parenthesis can be included in a name either as \e) or between \eQ
-and \eE. 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.
+and \eE. In addition to backslash processing, if the PCRE2_EXTENDED or 
+PCRE2_EXTENDED_MORE 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 and PCRE2_EXTENDED_MORE do not affect verb names unless
+PCRE2_ALT_VERBNAMES is also set.
 .P
 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
@@ -3614,6 +3620,6 @@ Cambridge, England.
 .rs
 .sp
 .nf
-Last updated: 28 July 2018
+Last updated: 03 August 2018
 Copyright (c) 1997-2018 University of Cambridge.
 .fi
diff --git a/doc/pcre2syntax.3 b/doc/pcre2syntax.3
index a281a5f..64b8bf1 100644
--- a/doc/pcre2syntax.3
+++ b/doc/pcre2syntax.3
@@ -1,4 +1,4 @@
-.TH PCRE2SYNTAX 3 "28 July 2018" "PCRE2 10.32"
+.TH PCRE2SYNTAX 3 "01 August 2018" "PCRE2 10.32"
 .SH NAME
 PCRE2 - Perl-compatible regular expressions (revised API)
 .SH "PCRE2 REGULAR EXPRESSION SYNTAX SUMMARY"
@@ -421,6 +421,8 @@ but some of them use Unicode properties if PCRE2_UCP is set. You can use
 .
 .SH "OPTION SETTING"
 .rs
+Changes of these options within a group are automatically cancelled at the end 
+of the group.
 .sp
   (?i)            caseless
   (?J)            allow duplicate names
@@ -619,6 +621,6 @@ Cambridge, England.
 .rs
 .sp
 .nf
-Last updated: 28 July 2018
+Last updated: 01 August 2018
 Copyright (c) 1997-2018 University of Cambridge.
 .fi
diff --git a/src/pcre2_compile.c b/src/pcre2_compile.c
index 5d299ee..f5eae11 100644
--- a/src/pcre2_compile.c
+++ b/src/pcre2_compile.c
@@ -2468,11 +2468,17 @@ while (ptr < ptrend)
         /* EITHER: not both options set */
         ((options & (PCRE2_EXTENDED | PCRE2_ALT_VERBNAMES)) !=
                     (PCRE2_EXTENDED | PCRE2_ALT_VERBNAMES)) ||
-        /* OR: character > 255 */
-        c > 255 ||
-        /* OR: not a # comment or white space */
-        (c != CHAR_NUMBER_SIGN && (cb->ctypes[c] & ctype_space) == 0)
-       ))
+#ifdef SUPPORT_UNICODE                     
+        /* OR: character > 255 AND not Unicode Pattern White Space */
+        (c > 255 && (c|1) != 0x200f && (c|1) != 0x2029) ||
+#endif         
+        /* OR: not a # comment or isspace() white space */
+        (c < 256 && c != CHAR_NUMBER_SIGN && (cb->ctypes[c] & ctype_space) == 0
+#ifdef SUPPORT_UNICODE
+        /* and not CHAR_NEL when Unicode is supported */
+          && c != CHAR_NEL
+#endif                     
+       )))
     {
     PCRE2_SIZE verbnamelength;
 
@@ -2554,11 +2560,18 @@ while (ptr < ptrend)
 
   /* Skip over whitespace and # comments in extended mode. Note that c is a
   character, not a code unit, so we must not use MAX_255 to test its size
-  because MAX_255 tests code units and is assumed TRUE in 8-bit mode. */
+  because MAX_255 tests code units and is assumed TRUE in 8-bit mode. The
+  whitespace characters are those designated as "Pattern White Space" by
+  Unicode, which are the isspace() characters plus CHAR_NEL (newline), which is 
+  U+0085 in Unicode, plus U+200E, U+200F, U+2028, and U+2029. These are a 
+  subset of space characters that match \h and \v. */
 
   if ((options & PCRE2_EXTENDED) != 0)
     {
     if (c < 256 && (cb->ctypes[c] & ctype_space) != 0) continue;
+#ifdef SUPPORT_UNICODE     
+    if (c == CHAR_NEL || (c|1) == 0x200f || (c|1) == 0x2029) continue;
+#endif     
     if (c == CHAR_NUMBER_SIGN)
       {
       while (ptr < ptrend)
diff --git a/testdata/testinput1 b/testdata/testinput1
index 09198dd..f4fb889 100644
--- a/testdata/testinput1
+++ b/testdata/testinput1
@@ -6257,5 +6257,5 @@ ef) x/x,mark
 \= Expect no match
     aBCDEF
     AbCDe f
-    
+
 # End of testinput1 
diff --git a/testdata/testinput4 b/testdata/testinput4
index 04469a8..3efb1ff 100644
--- a/testdata/testinput4
+++ b/testdata/testinput4
@@ -2293,5 +2293,20 @@
 
 /[\N{U+1234}]/utf
     \x{1234}
+    
+# Test the full list of Unicode "Pattern White Space" characters that are to
+# be ignored by /x. The pattern lines below may show up oddly in text editors
+# or when listed to the screen. Note that characters such as U+2002, which are
+# matched as space by \h and \v are *not* "Pattern White Space".
+
+/A…‎‏

B/x,utf
+    AB
+
+/A B/x,utf
+    A\x{2002}B
+\= Expect no match
+    AB
+    
+# ------- 
 
 # End of testinput4
diff --git a/testdata/testinput5 b/testdata/testinput5
index 070a2a5..e339808 100644
--- a/testdata/testinput5
+++ b/testdata/testinput5
@@ -2091,4 +2091,18 @@
 
 /\N{U}/
 
+# This tests the non-UTF Unicode NEL pattern whitespace character, only
+# recognized by PCRE2 with /x when there is Unicode support.
+
+/A      
+
B/x
+    AB 
+    
+# This tests Unicode Pattern White Space characters in verb names when they
+# are being processed with PCRE2_EXTENDED. Note: there are UTF-8 characters
+# with code points greater than 255 between A, B, and C in the pattern.
+
+/(*: A‎B
C)abc/x,utf,mark,alt_verbnames
+    abc
+
 # End of testinput5
diff --git a/testdata/testoutput1 b/testdata/testoutput1
index 06a5c8a..2778363 100644
--- a/testdata/testoutput1
+++ b/testdata/testoutput1
@@ -9920,5 +9920,5 @@ No match, mark = X
 No match
     AbCDe f
 No match
-    
+
 # End of testinput1 
diff --git a/testdata/testoutput4 b/testdata/testoutput4
index 3159378..db474ef 100644
--- a/testdata/testoutput4
+++ b/testdata/testoutput4
@@ -3711,5 +3711,23 @@ No match
 /[\N{U+1234}]/utf
     \x{1234}
  0: \x{1234}
+    
+# Test the full list of Unicode "Pattern White Space" characters that are to
+# be ignored by /x. The pattern lines below may show up oddly in text editors
+# or when listed to the screen. Note that characters such as U+2002, which are
+# matched as space by \h and \v are *not* "Pattern White Space".
+
+/A…‎‏

B/x,utf
+    AB
+ 0: AB
+
+/A B/x,utf
+    A\x{2002}B
+ 0: A\x{2002}B
+\= Expect no match
+    AB
+No match
+    
+# ------- 
 
 # End of testinput4
diff --git a/testdata/testoutput5 b/testdata/testoutput5
index c9fa633..a9552f4 100644
--- a/testdata/testoutput5
+++ b/testdata/testoutput5
@@ -4756,4 +4756,21 @@ Failed: error 178 at offset 5: digits missing in \x{} or \o{} or \N{U+}
 /\N{U}/
 Failed: error 137 at offset 2: PCRE2 does not support \F, \L, \l, \N{name}, \U, or \u
 
+# This tests the non-UTF Unicode NEL pattern whitespace character, only
+# recognized by PCRE2 with /x when there is Unicode support.
+
+/A      
+
B/x
+    AB 
+ 0: AB
+    
+# This tests Unicode Pattern White Space characters in verb names when they
+# are being processed with PCRE2_EXTENDED. Note: there are UTF-8 characters
+# with code points greater than 255 between A, B, and C in the pattern.
+
+/(*: A‎B
C)abc/x,utf,mark,alt_verbnames
+    abc
+ 0: abc
+MK: ABC
+
 # End of testinput5