From ba3d0edcbd97ae6a72ffb186a30703bf4b529101 Mon Sep 17 00:00:00 2001 From: Philip Hazel Date: Wed, 1 Dec 2021 16:21:08 +0000 Subject: [PATCH] Documentation update --- doc/html/pcre2compat.html | 73 +++++++++-------- doc/html/pcre2pattern.html | 18 +++-- doc/pcre2.txt | 159 ++++++++++++++++++++----------------- doc/pcre2compat.3 | 74 +++++++++-------- doc/pcre2pattern.3 | 23 +++--- 5 files changed, 190 insertions(+), 157 deletions(-) diff --git a/doc/html/pcre2compat.html b/doc/html/pcre2compat.html index eb82694..6bd4cf0 100644 --- a/doc/html/pcre2compat.html +++ b/doc/html/pcre2compat.html @@ -18,33 +18,41 @@ DIFFERENCES BETWEEN PCRE2 AND PERL

This document describes some of the differences in the ways that PCRE2 and Perl handle regular expressions. The differences described here are with respect to -Perl version 5.32.0, but as both Perl and PCRE2 are continually changing, the +Perl version 5.34.0, but as both Perl and PCRE2 are continually changing, the information may at times be out of date.

-1. PCRE2 has only a subset of Perl's Unicode support. Details of what it does +1. When PCRE2_DOTALL (equivalent to Perl's /s qualifier) is not set, the +behaviour of the '.' metacharacter differs from Perl. In PCRE2, '.' matches the +next character unless it is the start of a newline sequence. This means that, +if the newline setting is CR, CRLF, or NUL, '.' will match the code point LF +(0x0A) in ASCII/Unicode environments, and NL (either 0x15 or 0x25) when using +EBCDIC. In Perl, '.' appears never to match LF, even when 0x0A is not a newline +indicator. +

+

+2. PCRE2 has only a subset of Perl's Unicode support. Details of what it does have are given in the pcre2unicode page.

-2. Like Perl, PCRE2 allows repeat quantifiers on parenthesized assertions, but +3. Like Perl, PCRE2 allows repeat quantifiers on parenthesized assertions, but they do not mean what you might think. For example, (?!a){3} does not assert that the next three characters are not "a". It just asserts that the next character is not "a" three times (in principle; PCRE2 optimizes this to run the assertion just once). Perl allows some repeat quantifiers on other assertions, -for example, \b* (but not \b{3}, though oddly it does allow ^{3}), but these -do not seem to have any use. PCRE2 does not allow any kind of quantifier on -non-lookaround assertions. +for example, \b* , but these do not seem to have any use. PCRE2 does not allow +any kind of quantifier on non-lookaround assertions.

-3. Capture groups that occur inside negative lookaround assertions are counted, +4. Capture groups that occur inside negative lookaround assertions are counted, but their entries in the offsets vector are set only when a negative assertion is a condition that has a matching branch (that is, the condition is false). Perl may set such capture groups in other circumstances.

-4. The following Perl escape sequences are not supported: \F, \l, \L, \u, +5. The following Perl escape sequences are not supported: \F, \l, \L, \u, \U, and \N when followed by a character name. \N on its own, matching a non-newline character, and \N{U+dd..}, matching a Unicode code point, are supported. The escapes that modify the case of following letters are @@ -55,7 +63,7 @@ PCRE2_EXTRA_ALT_BSUX options is set, \U and \u are interpreted as ECMAScript interprets them.

-5. The Perl escape sequences \p, \P, and \X are supported only if PCRE2 is +6. The Perl escape sequences \p, \P, and \X are supported only if PCRE2 is built with Unicode support (the default). The properties that can be tested with \p and \P are limited to the general category properties such as Lu and Nd, script names such as Greek or Han, and the derived properties Any and L&. @@ -67,14 +75,14 @@ supports (such as \p{Letter}) are not supported by PCRE2, nor is it permitted to prefix any of these properties with "Is".

-6. PCRE2 supports the \Q...\E escape for quoting substrings. Characters +7. PCRE2 supports the \Q...\E escape for quoting substrings. Characters in between are treated as literals. However, this is slightly different from Perl in that $ and @ are also handled as literals inside the quotes. In Perl, -they cause variable interpolation (but of course PCRE2 does not have -variables). Also, Perl does "double-quotish backslash interpolation" on any -backslashes between \Q and \E which, its documentation says, "may lead to -confusing results". PCRE2 treats a backslash between \Q and \E just like any -other character. Note the following examples: +they cause variable interpolation (PCRE2 does not have variables). Also, Perl +does "double-quotish backslash interpolation" on any backslashes between \Q +and \E which, its documentation says, "may lead to confusing results". PCRE2 +treats a backslash between \Q and \E just like any other character. Note the +following examples: 

     Pattern            PCRE2 matches     Perl matches
 
@@ -88,19 +96,19 @@ The \Q...\E sequence is recognized both inside and outside character classes
 by both PCRE2 and Perl.
 

 

-7. Fairly obviously, PCRE2 does not support the (?{code}) and (??{code})
+8. Fairly obviously, PCRE2 does not support the (?{code}) and (??{code})
 constructions. However, PCRE2 does have a "callout" feature, which allows an
 external function to be called during pattern matching. See the
 pcre2callout
 documentation for details.
 

 

-8. Subroutine calls (whether recursive or not) were treated as atomic groups up
+9. Subroutine calls (whether recursive or not) were treated as atomic groups up
 to PCRE2 release 10.23, but from release 10.30 this changed, and backtracking
 into subroutine calls is now supported, as in Perl.
 

 

-9. In PCRE2, if any of the backtracking control verbs are used in a group that
+10. In PCRE2, if any of the backtracking control verbs are used in a group that
 is called as a subroutine (whether or not recursively), their effect is
 confined to that group; it does not extend to the surrounding pattern. This is
 not always the case in Perl. In particular, if (*THEN) is present in a group
@@ -109,20 +117,20 @@ the group does not contain any | characters. Note that such groups are
 processed as anchored at the point where they are tested.
 

 

-10. If a pattern contains more than one backtracking control verb, the first
+11. If a pattern contains more than one backtracking control verb, the first
 one that is backtracked onto acts. For example, in the pattern
 A(*COMMIT)B(*PRUNE)C a failure in B triggers (*COMMIT), but a failure in C
 triggers (*PRUNE). Perl's behaviour is more complex; in many cases it is the
 same as PCRE2, but there are cases where it differs.
 

 

-11. There are some differences that are concerned with the settings of captured
+12. There are some differences that are concerned with the settings of captured
 strings when part of a pattern is repeated. For example, matching "aba" against
 the pattern /^(a(b)?)+$/ in Perl leaves $2 unset, but in PCRE2 it is set to
 "b".
 

 

-12. PCRE2's handling of duplicate capture group numbers and names is not as
+13. PCRE2's handling of duplicate capture group numbers and names is not as
 general as Perl's. This is a consequence of the fact the PCRE2 works internally
 just with numbers, using an external table to translate between numbers and
 names. In particular, a pattern such as (?|(?<a>A)|(?<b>B)), where the two
@@ -132,42 +140,43 @@ to distinguish which group matched, because both names map to capture group
 number 1. To avoid this confusing situation, an error is given at compile time.
 

 

-13. Perl used to recognize comments in some places that PCRE2 does not, for
+14. Perl used to recognize comments in some places that PCRE2 does not, for
 example, between the ( and ? at the start of a group. If the /x modifier is
 set, Perl allowed white space between ( and ? though the latest Perls give an
 error (for a while it was just deprecated). There may still be some cases where
 Perl behaves differently.
 

 

-14. Perl, when in warning mode, gives warnings for character classes such as
+15. Perl, when in warning mode, gives warnings for character classes such as
 [A-\d] or [a-[:digit:]]. It then treats the hyphens as literals. PCRE2 has no
 warning features, so it gives an error in these cases because they are almost
 certainly user mistakes.
 

 

-15. In PCRE2, the upper/lower case character properties Lu and Ll are not
+16. In PCRE2, the upper/lower case character properties Lu and Ll are not
 affected when case-independent matching is specified. For example, \p{Lu}
 always matches an upper case letter. I think Perl has changed in this respect;
-in the release at the time of writing (5.32), \p{Lu} and \p{Ll} match all
+in the release at the time of writing (5.34), \p{Lu} and \p{Ll} match all
 letters, regardless of case, when case independence is specified.
 

 

-16. From release 5.32.0, Perl locks out the use of \K in lookaround
+17. From release 5.32.0, Perl locks out the use of \K in lookaround
 assertions. From release 10.38 PCRE2 does the same by default. However, there
 is an option for re-enabling the previous behaviour. When this option is set,
 \K is acted on when it occurs in positive assertions, but is ignored in
 negative assertions.
 

 

-17. PCRE2 provides some extensions to the Perl regular expression facilities.
+18. PCRE2 provides some extensions to the Perl regular expression facilities.
 Perl 5.10 included new features that were not in earlier versions of Perl, some
 of which (such as named parentheses) were in PCRE2 for some time before. This
-list is with respect to Perl 5.32:
+list is with respect to Perl 5.34:
 

 

 (a) Although lookbehind assertions in PCRE2 must match fixed length strings,
 each alternative toplevel branch of a lookbehind assertion can match a
-different length of string. Perl requires them all to have the same length.
+different length of string. Perl used to require them all to have the same
+length, but the latest version has some variable length support.
 

 

 (b) From PCRE2 10.23, backreferences to groups of fixed length are supported
@@ -221,12 +230,12 @@ extension to the lookaround facilities. The default, Perl-compatible
 lookarounds are atomic.
 

 

-18. The Perl /a modifier restricts /d numbers to pure ascii, and the /aa
+19. The Perl /a modifier restricts /d numbers to pure ascii, and the /aa
 modifier restricts /i case-insensitive matching to pure ascii, ignoring Unicode
 rules. This separation cannot be represented with PCRE2_UCP.
 

 

-19. Perl has different limits than PCRE2. See the
+20. Perl has different limits than PCRE2. See the
 pcre2limit
 documentation for details. Perl went with 5.10 from recursion to iteration
 keeping the intermediate matches on the heap, which is ~10% slower but does not
@@ -248,7 +257,7 @@ Cambridge, England.
 REVISION
 

 

-Last updated: 30 August 2021
+Last updated: 01 December 2021
 

 Copyright © 1997-2021 University of Cambridge.
 

diff --git a/doc/html/pcre2pattern.html b/doc/html/pcre2pattern.html
index 461140e..6afaf27 100644
--- a/doc/html/pcre2pattern.html
+++ b/doc/html/pcre2pattern.html
@@ -1341,15 +1341,17 @@ end of the subject in both modes, and if all branches of a pattern start with
 

 Outside a character class, a dot in the pattern matches any one character in
 the subject string except (by default) a character that signifies the end of a
-line.
+line. One or more characters may be specified as line terminators (see
+"Newline conventions"
+above).
 

 

-When a line ending is defined as a single character, dot never matches that
-character; when the two-character sequence CRLF is used, dot does not match CR
-if it is immediately followed by LF, but otherwise it matches all characters
-(including isolated CRs and LFs). When any Unicode line endings are being
-recognized, dot does not match CR or LF or any of the other line ending
-characters.
+Dot never matches a single line-ending character. When the two-character
+sequence CRLF is the only line ending, dot does not match CR if it is
+immediately followed by LF, but otherwise it matches all characters (including
+isolated CRs and LFs). When ANYCRLF is selected for line endings, no occurences
+of CR of LF match dot. When all Unicode line endings are being recognized, dot
+does not match CR or LF or any of the other line ending characters.
 

 

 The behaviour of dot with regard to newlines can be changed. If the
@@ -3859,7 +3861,7 @@ Cambridge, England.
 

 
REVISION

 

-Last updated: 30 August 2021
+Last updated: 01 December 2021
 

 Copyright © 1997-2021 University of Cambridge.
 

diff --git a/doc/pcre2.txt b/doc/pcre2.txt
index 9b49a76..103cb97 100644
--- a/doc/pcre2.txt
+++ b/doc/pcre2.txt
@@ -4899,57 +4899,63 @@ DIFFERENCES BETWEEN PCRE2 AND PERL
 
        This  document describes some of the differences in the ways that PCRE2
        and Perl handle regular expressions. The differences described here are
-       with  respect  to  Perl  version 5.32.0, but as both Perl and PCRE2 are
+       with  respect  to  Perl  version 5.34.0, but as both Perl and PCRE2 are
        continually changing, the information may at times be out of date.
 
-       1. PCRE2 has only a subset of Perl's Unicode support. Details  of  what
+       1. When PCRE2_DOTALL (equivalent to Perl's /s qualifier)  is  not  set,
+       the behaviour of the '.' metacharacter differs from Perl. In PCRE2, '.'
+       matches the next character unless it is the  start  of  a  newline  se-
+       quence.  This  means  that, if the newline setting is CR, CRLF, or NUL,
+       '.' will match the code point LF (0x0A) in ASCII/Unicode  environments,
+       and  NL  (either  0x15 or 0x25) when using EBCDIC. In Perl, '.' appears
+       never to match LF, even when 0x0A is not a newline indicator.
+
+       2. PCRE2 has only a subset of Perl's Unicode support. Details  of  what
        it does have are given in the pcre2unicode page.
 
-       2.  Like  Perl, PCRE2 allows repeat quantifiers on parenthesized asser-
+       3.  Like  Perl, PCRE2 allows repeat quantifiers on parenthesized asser-
        tions, but they do not mean what you might think. For example, (?!a){3}
        does not assert that the next three characters are not "a". It just as-
        serts that the next character is not "a"  three  times  (in  principle;
        PCRE2  optimizes this to run the assertion just once). Perl allows some
-       repeat quantifiers on other  assertions,  for  example,  \b*  (but  not
-       \b{3},  though oddly it does allow ^{3}), but these do not seem to have
-       any use. PCRE2 does not allow any kind of quantifier on  non-lookaround
-       assertions.
+       repeat quantifiers on other assertions, for example, \b* , but these do
+       not  seem  to have any use. PCRE2 does not allow any kind of quantifier
+       on non-lookaround assertions.
 
-       3.  Capture groups that occur inside negative lookaround assertions are
-       counted, but their entries in the offsets vector are set  only  when  a
-       negative  assertion is a condition that has a matching branch (that is,
-       the condition is false).  Perl may set such  capture  groups  in  other
+       4. Capture groups that occur inside negative lookaround assertions  are
+       counted,  but  their  entries in the offsets vector are set only when a
+       negative assertion is a condition that has a matching branch (that  is,
+       the  condition  is  false).   Perl may set such capture groups in other
        circumstances.
 
-       4.  The  following Perl escape sequences are not supported: \F, \l, \L,
+       5. The following Perl escape sequences are not supported: \F,  \l,  \L,
        \u, \U, and \N when followed by a character name. \N on its own, match-
-       ing  a  non-newline  character, and \N{U+dd..}, matching a Unicode code
-       point, are supported. The escapes that modify  the  case  of  following
-       letters  are  implemented by Perl's general string-handling and are not
+       ing a non-newline character, and \N{U+dd..}, matching  a  Unicode  code
+       point,  are  supported.  The  escapes that modify the case of following
+       letters are implemented by Perl's general string-handling and  are  not
        part of its pattern matching engine. If any of these are encountered by
-       PCRE2,  an  error  is  generated  by default. However, if either of the
-       PCRE2_ALT_BSUX or PCRE2_EXTRA_ALT_BSUX options is set, \U  and  \u  are
+       PCRE2, an error is generated by default.  However,  if  either  of  the
+       PCRE2_ALT_BSUX  or  PCRE2_EXTRA_ALT_BSUX  options is set, \U and \u are
        interpreted as ECMAScript interprets them.
 
-       5. The Perl escape sequences \p, \P, and \X are supported only if PCRE2
+       6. The Perl escape sequences \p, \P, and \X are supported only if PCRE2
        is built with Unicode support (the default). The properties that can be
-       tested  with  \p  and \P are limited to the general category properties
-       such as Lu and Nd, script names such as Greek or Han, and  the  derived
-       properties  Any and L&.  Both PCRE2 and Perl support the Cs (surrogate)
-       property, but in PCRE2 its use is limited. See the  pcre2pattern  docu-
-       mentation  for  details. The long synonyms for property names that Perl
-       supports (such as \p{Letter}) are not supported by  PCRE2,  nor  is  it
+       tested with \p and \P are limited to the  general  category  properties
+       such  as  Lu and Nd, script names such as Greek or Han, and the derived
+       properties Any and L&.  Both PCRE2 and Perl support the Cs  (surrogate)
+       property,  but  in PCRE2 its use is limited. See the pcre2pattern docu-
+       mentation for details. The long synonyms for property names  that  Perl
+       supports  (such  as  \p{Letter})  are not supported by PCRE2, nor is it
        permitted to prefix any of these properties with "Is".
 
-       6. PCRE2 supports the \Q...\E escape for quoting substrings. Characters
+       7. PCRE2 supports the \Q...\E escape for quoting substrings. Characters
        in between are treated as literals. However, this is slightly different
-       from  Perl  in  that  $  and  @ are also handled as literals inside the
-       quotes. In Perl, they cause variable interpolation (but of course PCRE2
-       does not have variables). Also, Perl does "double-quotish backslash in-
-       terpolation" on any backslashes between \Q and \E which, its documenta-
-       tion  says,  "may  lead to confusing results". PCRE2 treats a backslash
-       between \Q and \E just like any other character. Note the following ex-
-       amples:
+       from Perl in that $ and @ are  also  handled  as  literals  inside  the
+       quotes. In Perl, they cause variable interpolation (PCRE2 does not have
+       variables). Also, Perl does "double-quotish backslash interpolation" on
+       any  backslashes  between \Q and \E which, its documentation says, "may
+       lead to confusing results". PCRE2 treats a backslash between \Q and  \E
+       just like any other character. Note the following examples:
 
            Pattern            PCRE2 matches     Perl matches
 
@@ -4963,16 +4969,16 @@ DIFFERENCES BETWEEN PCRE2 AND PERL
        The  \Q...\E  sequence  is recognized both inside and outside character
        classes by both PCRE2 and Perl.
 
-       7.  Fairly  obviously,  PCRE2  does  not  support  the  (?{code})   and
+       8.  Fairly  obviously,  PCRE2  does  not  support  the  (?{code})   and
        (??{code}) constructions. However, PCRE2 does have a "callout" feature,
        which allows an external function to be called during pattern matching.
        See the pcre2callout documentation for details.
 
-       8.  Subroutine  calls (whether recursive or not) were treated as atomic
+       9.  Subroutine  calls (whether recursive or not) were treated as atomic
        groups up to PCRE2 release 10.23, but from release 10.30 this  changed,
        and backtracking into subroutine calls is now supported, as in Perl.
 
-       9.  In  PCRE2,  if  any of the backtracking control verbs are used in a
+       10.  In  PCRE2,  if any of the backtracking control verbs are used in a
        group that is called as a  subroutine  (whether  or  not  recursively),
        their  effect is confined to that group; it does not extend to the sur-
        rounding pattern. This is not always the case in Perl.  In  particular,
@@ -4981,18 +4987,18 @@ DIFFERENCES BETWEEN PCRE2 AND PERL
        |  characters.  Note  that such groups are processed as anchored at the
        point where they are tested.
 
-       10. If a pattern contains more than one backtracking control verb,  the
+       11. If a pattern contains more than one backtracking control verb,  the
        first  one  that  is backtracked onto acts. For example, in the pattern
        A(*COMMIT)B(*PRUNE)C a failure in B triggers (*COMMIT), but  a  failure
        in C triggers (*PRUNE). Perl's behaviour is more complex; in many cases
        it is the same as PCRE2, but there are cases where it differs.
 
-       11. There are some differences that are concerned with the settings  of
+       12. There are some differences that are concerned with the settings  of
        captured  strings  when  part  of  a  pattern is repeated. For example,
        matching "aba" against the pattern /^(a(b)?)+$/ in Perl leaves  $2  un-
        set, but in PCRE2 it is set to "b".
 
-       12.  PCRE2's  handling  of duplicate capture group numbers and names is
+       13.  PCRE2's  handling  of duplicate capture group numbers and names is
        not as general as Perl's. This is a consequence of the fact  the  PCRE2
        works  internally  just with numbers, using an external table to trans-
        late between numbers and  names.  In  particular,  a  pattern  such  as
@@ -5002,90 +5008,91 @@ DIFFERENCES BETWEEN PCRE2 AND PERL
        group matched, because both names map to capture  group  number  1.  To
        avoid this confusing situation, an error is given at compile time.
 
-       13. Perl used to recognize comments in some places that PCRE2 does not,
+       14. Perl used to recognize comments in some places that PCRE2 does not,
        for example, between the ( and ? at the start of a  group.  If  the  /x
        modifier  is  set,  Perl allowed white space between ( and ? though the
        latest Perls give an error (for a while it was just deprecated).  There
        may still be some cases where Perl behaves differently.
 
-       14.  Perl,  when  in warning mode, gives warnings for character classes
+       15.  Perl,  when  in warning mode, gives warnings for character classes
        such as [A-\d] or [a-[:digit:]]. It then treats the hyphens  as  liter-
        als. PCRE2 has no warning features, so it gives an error in these cases
        because they are almost certainly user mistakes.
 
-       15. In PCRE2, the upper/lower case character properties Lu and  Ll  are
+       16. In PCRE2, the upper/lower case character properties Lu and  Ll  are
        not  affected when case-independent matching is specified. For example,
        \p{Lu} always matches an upper case letter. I think Perl has changed in
-       this  respect; in the release at the time of writing (5.32), \p{Lu} and
+       this  respect; in the release at the time of writing (5.34), \p{Lu} and
        \p{Ll} match all letters, regardless of case, when case independence is
        specified.
 
-       16. From release 5.32.0, Perl locks out the use of \K in lookaround as-
+       17. From release 5.32.0, Perl locks out the use of \K in lookaround as-
        sertions. From release 10.38 PCRE2 does the same by  default.  However,
        there  is  an  option for re-enabling the previous behaviour. When this
        option is set, \K is acted on when it occurs  in  positive  assertions,
        but is ignored in negative assertions.
 
-       17.  PCRE2  provides some extensions to the Perl regular expression fa-
+       18.  PCRE2  provides some extensions to the Perl regular expression fa-
        cilities.  Perl 5.10 included new features that  were  not  in  earlier
        versions  of  Perl,  some  of which (such as named parentheses) were in
-       PCRE2 for some time before. This list is with respect to Perl 5.32:
+       PCRE2 for some time before. This list is with respect to Perl 5.34:
 
        (a) Although lookbehind assertions in PCRE2  must  match  fixed  length
        strings, each alternative toplevel branch of a lookbehind assertion can
-       match a different length of string. Perl requires them all to have  the
-       same length.
+       match a different length of string. Perl used to require  them  all  to
+       have  the  same length, but the latest version has some variable length
+       support.
 
        (b) From PCRE2 10.23, backreferences to groups of fixed length are sup-
-       ported in lookbehinds, provided that there is no possibility of  refer-
-       encing  a  non-unique  number or name. Perl does not support backrefer-
+       ported  in lookbehinds, provided that there is no possibility of refer-
+       encing a non-unique number or name. Perl does  not  support  backrefer-
        ences in lookbehinds.
 
-       (c) If PCRE2_DOLLAR_ENDONLY is set and PCRE2_MULTILINE is not set,  the
+       (c)  If PCRE2_DOLLAR_ENDONLY is set and PCRE2_MULTILINE is not set, the
        $ meta-character matches only at the very end of the string.
 
-       (d)  A  backslash  followed  by  a  letter  with  no special meaning is
+       (d) A backslash followed  by  a  letter  with  no  special  meaning  is
        faulted. (Perl can be made to issue a warning.)
 
-       (e) If PCRE2_UNGREEDY is set, the greediness of the repetition  quanti-
+       (e)  If PCRE2_UNGREEDY is set, the greediness of the repetition quanti-
        fiers is inverted, that is, by default they are not greedy, but if fol-
        lowed by a question mark they are.
 
-       (f) PCRE2_ANCHORED can be used at matching time to force a  pattern  to
+       (f)  PCRE2_ANCHORED  can be used at matching time to force a pattern to
        be tried only at the first matching position in the subject string.
 
-       (g)     The     PCRE2_NOTBOL,    PCRE2_NOTEOL,    PCRE2_NOTEMPTY    and
+       (g)    The    PCRE2_NOTBOL,    PCRE2_NOTEOL,     PCRE2_NOTEMPTY     and
        PCRE2_NOTEMPTY_ATSTART options have no Perl equivalents.
 
-       (h) The \R escape sequence can be restricted to match only CR,  LF,  or
+       (h)  The  \R escape sequence can be restricted to match only CR, LF, or
        CRLF by the PCRE2_BSR_ANYCRLF option.
 
-       (i)  The  callout  facility is PCRE2-specific. Perl supports codeblocks
+       (i) The callout facility is PCRE2-specific.  Perl  supports  codeblocks
        and variable interpolation, but not general hooks on every match.
 
        (j) The partial matching facility is PCRE2-specific.
 
-       (k) The alternative matching function (pcre2_dfa_match() matches  in  a
+       (k)  The  alternative matching function (pcre2_dfa_match() matches in a
        different way and is not Perl-compatible.
 
-       (l)  PCRE2 recognizes some special sequences such as (*CR) or (*NO_JIT)
-       at the start of a pattern. These set overall  options  that  cannot  be
+       (l) PCRE2 recognizes some special sequences such as (*CR) or  (*NO_JIT)
+       at  the  start  of  a pattern. These set overall options that cannot be
        changed within the pattern.
 
-       (m)  PCRE2  supports non-atomic positive lookaround assertions. This is
+       (m) PCRE2 supports non-atomic positive lookaround assertions.  This  is
        an extension to the lookaround facilities. The default, Perl-compatible
        lookarounds are atomic.
 
-       18.  The  Perl  /a modifier restricts /d numbers to pure ascii, and the
-       /aa modifier restricts /i case-insensitive matching to pure ascii,  ig-
-       noring  Unicode  rules.  This  separation  cannot  be  represented with
+       19. The Perl /a modifier restricts /d numbers to pure  ascii,  and  the
+       /aa  modifier restricts /i case-insensitive matching to pure ascii, ig-
+       noring Unicode  rules.  This  separation  cannot  be  represented  with
        PCRE2_UCP.
 
-       19. Perl has different limits than PCRE2. See the pcre2limit documenta-
+       20. Perl has different limits than PCRE2. See the pcre2limit documenta-
        tion for details. Perl went with 5.10 from recursion to iteration keep-
        ing the intermediate matches on the heap, which is ~10% slower but does
-       not  fall into any stack-overflow limit. PCRE2 made a similar change at
-       release 10.30, and also has many build-time and  run-time  customizable
+       not fall into any stack-overflow limit. PCRE2 made a similar change  at
+       release  10.30,  and also has many build-time and run-time customizable
        limits.
 
 
@@ -5098,7 +5105,7 @@ AUTHOR
 
 REVISION
 
-       Last updated: 30 August 2021
+       Last updated: 01 December 2021
        Copyright (c) 1997-2021 University of Cambridge.
 ------------------------------------------------------------------------------
  
@@ -7277,14 +7284,16 @@ FULL STOP (PERIOD, DOT) AND \N
 
        Outside a character class, a dot in the pattern matches any one charac-
        ter  in  the subject string except (by default) a character that signi-
-       fies the end of a line.
+       fies the end of a line. One or more characters may be specified as line
+       terminators (see "Newline conventions" above).
 
-       When a line ending is defined as a single character, dot never  matches
-       that  character; when the two-character sequence CRLF is used, dot does
-       not match CR if it is immediately followed  by  LF,  but  otherwise  it
-       matches  all characters (including isolated CRs and LFs). When any Uni-
-       code line endings are being recognized, dot does not match CR or LF  or
-       any of the other line ending characters.
+       Dot  never matches a single line-ending character. When the two-charac-
+       ter sequence CRLF is the only line ending, dot does not match CR if  it
+       is  immediately followed by LF, but otherwise it matches all characters
+       (including isolated CRs and LFs). When ANYCRLF  is  selected  for  line
+       endings,  no  occurences  of  CR of LF match dot. When all Unicode line
+       endings are being recognized, dot does not match CR or LF or any of the
+       other line ending characters.
 
        The  behaviour  of  dot  with regard to newlines can be changed. If the
        PCRE2_DOTALL option is set, a dot matches any  one  character,  without
@@ -9650,7 +9659,7 @@ AUTHOR
 
 REVISION
 
-       Last updated: 30 August 2021
+       Last updated: 01 December 2021
        Copyright (c) 1997-2021 University of Cambridge.
 ------------------------------------------------------------------------------
  
diff --git a/doc/pcre2compat.3 b/doc/pcre2compat.3
index 311d6eb..c463034 100644
--- a/doc/pcre2compat.3
+++ b/doc/pcre2compat.3
@@ -1,4 +1,4 @@
-.TH PCRE2COMPAT 3 "30 August 2021" "PCRE2 10.38"
+.TH PCRE2COMPAT 3 "01 December 2021" "PCRE2 10.40"
 .SH NAME
 PCRE2 - Perl-compatible regular expressions (revised API)
 .SH "DIFFERENCES BETWEEN PCRE2 AND PERL"
@@ -6,31 +6,38 @@ PCRE2 - Perl-compatible regular expressions (revised API)
 .sp
 This document describes some of the differences in the ways that PCRE2 and Perl
 handle regular expressions. The differences described here are with respect to
-Perl version 5.32.0, but as both Perl and PCRE2 are continually changing, the
+Perl version 5.34.0, but as both Perl and PCRE2 are continually changing, the
 information may at times be out of date.
 .P
-1. PCRE2 has only a subset of Perl's Unicode support. Details of what it does
+1. When PCRE2_DOTALL (equivalent to Perl's /s qualifier) is not set, the
+behaviour of the '.' metacharacter differs from Perl. In PCRE2, '.' matches the
+next character unless it is the start of a newline sequence. This means that,
+if the newline setting is CR, CRLF, or NUL, '.' will match the code point LF
+(0x0A) in ASCII/Unicode environments, and NL (either 0x15 or 0x25) when using
+EBCDIC. In Perl, '.' appears never to match LF, even when 0x0A is not a newline
+indicator.
+.P
+2. PCRE2 has only a subset of Perl's Unicode support. Details of what it does
 have are given in the
 .\" HREF
 \fBpcre2unicode\fP
 .\"
 page.
 .P
-2. Like Perl, PCRE2 allows repeat quantifiers on parenthesized assertions, but
+3. Like Perl, PCRE2 allows repeat quantifiers on parenthesized assertions, but
 they do not mean what you might think. For example, (?!a){3} does not assert
 that the next three characters are not "a". It just asserts that the next
 character is not "a" three times (in principle; PCRE2 optimizes this to run the
 assertion just once). Perl allows some repeat quantifiers on other assertions,
-for example, \eb* (but not \eb{3}, though oddly it does allow ^{3}), but these
-do not seem to have any use. PCRE2 does not allow any kind of quantifier on
-non-lookaround assertions.
+for example, \eb* , but these do not seem to have any use. PCRE2 does not allow
+any kind of quantifier on non-lookaround assertions.
 .P
-3. Capture groups that occur inside negative lookaround assertions are counted,
+4. Capture groups that occur inside negative lookaround assertions are counted,
 but their entries in the offsets vector are set only when a negative assertion
 is a condition that has a matching branch (that is, the condition is false).
 Perl may set such capture groups in other circumstances.
 .P
-4. The following Perl escape sequences are not supported: \eF, \el, \eL, \eu,
+5. The following Perl escape sequences are not supported: \eF, \el, \eL, \eu,
 \eU, and \eN when followed by a character name. \eN on its own, matching a
 non-newline character, and \eN{U+dd..}, matching a Unicode code point, are
 supported. The escapes that modify the case of following letters are
@@ -40,7 +47,7 @@ generated by default. However, if either of the PCRE2_ALT_BSUX or
 PCRE2_EXTRA_ALT_BSUX options is set, \eU and \eu are interpreted as ECMAScript
 interprets them.
 .P
-5. The Perl escape sequences \ep, \eP, and \eX are supported only if PCRE2 is
+6. The Perl escape sequences \ep, \eP, and \eX are supported only if PCRE2 is
 built with Unicode support (the default). The properties that can be tested
 with \ep and \eP are limited to the general category properties such as Lu and
 Nd, script names such as Greek or Han, and the derived properties Any and L&.
@@ -53,14 +60,14 @@ documentation for details. The long synonyms for property names that Perl
 supports (such as \ep{Letter}) are not supported by PCRE2, nor is it permitted
 to prefix any of these properties with "Is".
 .P
-6. PCRE2 supports the \eQ...\eE escape for quoting substrings. Characters
+7. PCRE2 supports the \eQ...\eE escape for quoting substrings. Characters
 in between are treated as literals. However, this is slightly different from
 Perl in that $ and @ are also handled as literals inside the quotes. In Perl,
-they cause variable interpolation (but of course PCRE2 does not have
-variables). Also, Perl does "double-quotish backslash interpolation" on any
-backslashes between \eQ and \eE which, its documentation says, "may lead to
-confusing results". PCRE2 treats a backslash between \eQ and \eE just like any
-other character. Note the following examples:
+they cause variable interpolation (PCRE2 does not have variables). Also, Perl
+does "double-quotish backslash interpolation" on any backslashes between \eQ
+and \eE which, its documentation says, "may lead to confusing results". PCRE2
+treats a backslash between \eQ and \eE just like any other character. Note the
+following examples:
 .sp
     Pattern            PCRE2 matches     Perl matches
 .sp
@@ -75,7 +82,7 @@ other character. Note the following examples:
 The \eQ...\eE sequence is recognized both inside and outside character classes
 by both PCRE2 and Perl.
 .P
-7. Fairly obviously, PCRE2 does not support the (?{code}) and (??{code})
+8. Fairly obviously, PCRE2 does not support the (?{code}) and (??{code})
 constructions. However, PCRE2 does have a "callout" feature, which allows an
 external function to be called during pattern matching. See the
 .\" HREF
@@ -83,11 +90,11 @@ external function to be called during pattern matching. See the
 .\"
 documentation for details.
 .P
-8. Subroutine calls (whether recursive or not) were treated as atomic groups up
+9. Subroutine calls (whether recursive or not) were treated as atomic groups up
 to PCRE2 release 10.23, but from release 10.30 this changed, and backtracking
 into subroutine calls is now supported, as in Perl.
 .P
-9. In PCRE2, if any of the backtracking control verbs are used in a group that
+10. In PCRE2, if any of the backtracking control verbs are used in a group that
 is called as a subroutine (whether or not recursively), their effect is
 confined to that group; it does not extend to the surrounding pattern. This is
 not always the case in Perl. In particular, if (*THEN) is present in a group
@@ -95,18 +102,18 @@ that is called as a subroutine, its action is limited to that group, even if
 the group does not contain any | characters. Note that such groups are
 processed as anchored at the point where they are tested.
 .P
-10. If a pattern contains more than one backtracking control verb, the first
+11. If a pattern contains more than one backtracking control verb, the first
 one that is backtracked onto acts. For example, in the pattern
 A(*COMMIT)B(*PRUNE)C a failure in B triggers (*COMMIT), but a failure in C
 triggers (*PRUNE). Perl's behaviour is more complex; in many cases it is the
 same as PCRE2, but there are cases where it differs.
 .P
-11. There are some differences that are concerned with the settings of captured
+12. There are some differences that are concerned with the settings of captured
 strings when part of a pattern is repeated. For example, matching "aba" against
 the pattern /^(a(b)?)+$/ in Perl leaves $2 unset, but in PCRE2 it is set to
 "b".
 .P
-12. PCRE2's handling of duplicate capture group numbers and names is not as
+13. PCRE2's handling of duplicate capture group numbers and names is not as
 general as Perl's. This is a consequence of the fact the PCRE2 works internally
 just with numbers, using an external table to translate between numbers and
 names. In particular, a pattern such as (?|(?A)|(?B)), where the two
@@ -115,37 +122,38 @@ causes an error at compile time. If it were allowed, it would not be possible
 to distinguish which group matched, because both names map to capture group
 number 1. To avoid this confusing situation, an error is given at compile time.
 .P
-13. Perl used to recognize comments in some places that PCRE2 does not, for
+14. Perl used to recognize comments in some places that PCRE2 does not, for
 example, between the ( and ? at the start of a group. If the /x modifier is
 set, Perl allowed white space between ( and ? though the latest Perls give an
 error (for a while it was just deprecated). There may still be some cases where
 Perl behaves differently.
 .P
-14. Perl, when in warning mode, gives warnings for character classes such as
+15. Perl, when in warning mode, gives warnings for character classes such as
 [A-\ed] or [a-[:digit:]]. It then treats the hyphens as literals. PCRE2 has no
 warning features, so it gives an error in these cases because they are almost
 certainly user mistakes.
 .P
-15. In PCRE2, the upper/lower case character properties Lu and Ll are not
+16. In PCRE2, the upper/lower case character properties Lu and Ll are not
 affected when case-independent matching is specified. For example, \ep{Lu}
 always matches an upper case letter. I think Perl has changed in this respect;
-in the release at the time of writing (5.32), \ep{Lu} and \ep{Ll} match all
+in the release at the time of writing (5.34), \ep{Lu} and \ep{Ll} match all
 letters, regardless of case, when case independence is specified.
 .P
-16. From release 5.32.0, Perl locks out the use of \eK in lookaround
+17. From release 5.32.0, Perl locks out the use of \eK in lookaround
 assertions. From release 10.38 PCRE2 does the same by default. However, there
 is an option for re-enabling the previous behaviour. When this option is set,
 \eK is acted on when it occurs in positive assertions, but is ignored in
 negative assertions.
 .P
-17. PCRE2 provides some extensions to the Perl regular expression facilities.
+18. PCRE2 provides some extensions to the Perl regular expression facilities.
 Perl 5.10 included new features that were not in earlier versions of Perl, some
 of which (such as named parentheses) were in PCRE2 for some time before. This
-list is with respect to Perl 5.32:
+list is with respect to Perl 5.34:
 .sp
 (a) Although lookbehind assertions in PCRE2 must match fixed length strings,
 each alternative toplevel branch of a lookbehind assertion can match a
-different length of string. Perl requires them all to have the same length.
+different length of string. Perl used to require them all to have the same
+length, but the latest version has some variable length support.
 .sp
 (b) From PCRE2 10.23, backreferences to groups of fixed length are supported
 in lookbehinds, provided that there is no possibility of referencing a
@@ -186,11 +194,11 @@ the pattern.
 extension to the lookaround facilities. The default, Perl-compatible
 lookarounds are atomic.
 .P
-18. The Perl /a modifier restricts /d numbers to pure ascii, and the /aa
+19. The Perl /a modifier restricts /d numbers to pure ascii, and the /aa
 modifier restricts /i case-insensitive matching to pure ascii, ignoring Unicode
 rules. This separation cannot be represented with PCRE2_UCP.
 .P
-19. Perl has different limits than PCRE2. See the
+20. Perl has different limits than PCRE2. See the
 .\" HREF
 \fBpcre2limit\fP
 .\"
@@ -214,6 +222,6 @@ Cambridge, England.
 .rs
 .sp
 .nf
-Last updated: 30 August 2021
+Last updated: 01 December 2021
 Copyright (c) 1997-2021 University of Cambridge.
 .fi
diff --git a/doc/pcre2pattern.3 b/doc/pcre2pattern.3
index c346d4b..87c7252 100644
--- a/doc/pcre2pattern.3
+++ b/doc/pcre2pattern.3
@@ -1,4 +1,4 @@
-.TH PCRE2PATTERN 3 "3o0 August 2021" "PCRE2 10.38"
+.TH PCRE2PATTERN 3 "01 December 2021" "PCRE2 10.40"
 .SH NAME
 PCRE2 - Perl-compatible regular expressions (revised API)
 .SH "PCRE2 REGULAR EXPRESSION DETAILS"
@@ -1335,14 +1335,19 @@ end of the subject in both modes, and if all branches of a pattern start with
 .sp
 Outside a character class, a dot in the pattern matches any one character in
 the subject string except (by default) a character that signifies the end of a
-line.
+line. One or more characters may be specified as line terminators (see
+.\" HTML 
+.\" 
+"Newline conventions"
+.\"
+above).
 .P
-When a line ending is defined as a single character, dot never matches that
-character; when the two-character sequence CRLF is used, dot does not match CR
-if it is immediately followed by LF, but otherwise it matches all characters
-(including isolated CRs and LFs). When any Unicode line endings are being
-recognized, dot does not match CR or LF or any of the other line ending
-characters.
+Dot never matches a single line-ending character. When the two-character
+sequence CRLF is the only line ending, dot does not match CR if it is
+immediately followed by LF, but otherwise it matches all characters (including
+isolated CRs and LFs). When ANYCRLF is selected for line endings, no occurences
+of CR of LF match dot. When all Unicode line endings are being recognized, dot
+does not match CR or LF or any of the other line ending characters.
 .P
 The behaviour of dot with regard to newlines can be changed. If the
 PCRE2_DOTALL option is set, a dot matches any one character, without exception.
@@ -3904,6 +3909,6 @@ Cambridge, England.
 .rs
 .sp
 .nf
-Last updated: 30 August 2021
+Last updated: 01 December 2021
 Copyright (c) 1997-2021 University of Cambridge.
 .fi