[Pcre-svn] [1277] code/trunk/doc: Documentation update

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Revision: 1277
          http://www.exim.org/viewvc/pcre2?view=rev&revision=1277
Author:   ph10
Date:     2020-10-07 17:27:20 +0100 (Wed, 07 Oct 2020)
Log Message:
-----------
Documentation update


Modified Paths:
--------------
    code/trunk/doc/html/pcre2api.html
    code/trunk/doc/html/pcre2compat.html
    code/trunk/doc/html/pcre2pattern.html
    code/trunk/doc/pcre2.txt
    code/trunk/doc/pcre2compat.3
    code/trunk/doc/pcre2pattern.3


Modified: code/trunk/doc/html/pcre2api.html
===================================================================
--- code/trunk/doc/html/pcre2api.html    2020-10-06 08:04:40 UTC (rev 1276)
+++ code/trunk/doc/html/pcre2api.html    2020-10-07 16:27:20 UTC (rev 1277)
@@ -1492,10 +1492,13 @@
 changed within a pattern by a (?i) option setting. If either PCRE2_UTF or
 PCRE2_UCP is set, Unicode properties are used for all characters with more than
 one other case, and for all characters whose code points are greater than
-U+007F. For lower valued characters with only one other case, a lookup table is
-used for speed. When neither PCRE2_UTF nor PCRE2_UCP is set, a lookup table is
-used for all code points less than 256, and higher code points (available only
-in 16-bit or 32-bit mode) are treated as not having another case.
+U+007F. Note that there are two ASCII characters, K and S, that, in addition to
+their lower case ASCII equivalents, are case-equivalent with U+212A (Kelvin
+sign) and U+017F (long S) respectively. For lower valued characters with only
+one other case, a lookup table is used for speed. When neither PCRE2_UTF nor
+PCRE2_UCP is set, a lookup table is used for all code points less than 256, and
+higher code points (available only in 16-bit or 32-bit mode) are treated as not
+having another case.
 <pre>
   PCRE2_DOLLAR_ENDONLY
 </pre>
@@ -3956,7 +3959,7 @@
 </P>
 <br><a name="SEC42" href="#TOC1">REVISION</a><br>
 <P>
-Last updated: 19 March 2020
+Last updated: 05 October 2020
 <br>
 Copyright &copy; 1997-2020 University of Cambridge.
 <br>


Modified: code/trunk/doc/html/pcre2compat.html
===================================================================
--- code/trunk/doc/html/pcre2compat.html    2020-10-06 08:04:40 UTC (rev 1276)
+++ code/trunk/doc/html/pcre2compat.html    2020-10-07 16:27:20 UTC (rev 1277)
@@ -16,10 +16,10 @@
 DIFFERENCES BETWEEN PCRE2 AND PERL
 </b><br>
 <P>
-This document describes the differences in the ways that PCRE2 and Perl handle
-regular expressions. The differences described here are with respect to Perl
-versions 5.26, but as both Perl and PCRE2 are continually changing, the
-information may sometimes be out of date.
+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
+information may at times be out of date.
 </P>
 <P>
 1. PCRE2 has only a subset of Perl's Unicode support. Details of what it does
@@ -33,12 +33,15 @@
 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}), but these do not seem to have any use.
+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.
 </P>
 <P>
 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).
+is a condition that has a matching branch (that is, the condition is false). 
+Perl may set such capture groups in other circumstances.
 </P>
 <P>
 4. The following Perl escape sequences are not supported: \F, \l, \L, \u,
@@ -56,10 +59,12 @@
 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&.
-PCRE2 does support the Cs (surrogate) property, which Perl does not; the Perl
-documentation says "Because Perl hides the need for the user to understand the
-internal representation of Unicode characters, there is no need to implement
-the somewhat messy concept of surrogates."
+Both PCRE2 and Perl support the Cs (surrogate) property, but in PCRE2 its use
+is limited. See the
+<a href="pcre2pattern.html"><b>pcre2pattern</b></a>
+documentation 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".
 </P>
 <P>
 6. PCRE2 supports the \Q...\E escape for quoting substrings. Characters
@@ -79,7 +84,8 @@
     \QA\B\E            A\B               A\B
     \Q\\E              \                 \\E
 </pre>
-The \Q...\E sequence is recognized both inside and outside character classes.
+The \Q...\E sequence is recognized both inside and outside character classes 
+by both PCRE2 and Perl.
 </P>
 <P>
 7. Fairly obviously, PCRE2 does not support the (?{code}) and (??{code})
@@ -94,13 +100,13 @@
 into subroutine calls is now supported, as in Perl.
 </P>
 <P>
-9. 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 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.
+9. 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
+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>
 <P>
 10. If a pattern contains more than one backtracking control verb, the first
@@ -110,20 +116,16 @@
 same as PCRE2, but there are cases where it differs.
 </P>
 <P>
-11. Most backtracking verbs in assertions have their normal actions. They are
-not confined to the assertion.
-</P>
-<P>
-12. There are some differences that are concerned with the settings of captured
+11. 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>
 <P>
-13. PCRE2's handling of duplicate capture group numbers and names is not as
+12. 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 (?|(?&#60;a&#62;A)|(?&#60;b&#62;B), where the two
+names. In particular, a pattern such as (?|(?&#60;a&#62;A)|(?&#60;b&#62;B)), where the two
 capture groups have the same number but different names, is not supported, and
 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
@@ -130,7 +132,7 @@
 number 1. To avoid this confusing situation, an error is given at compile time.
 </P>
 <P>
-14. Perl used to recognize comments in some places that PCRE2 does not, for
+13. 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
@@ -137,28 +139,33 @@
 Perl behaves differently.
 </P>
 <P>
-15. Perl, when in warning mode, gives warnings for character classes such as
+14. 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.
 </P>
 <P>
-16. In PCRE2, the upper/lower case character properties Lu and Ll are not
+15. 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 (5.24), \p{Lu} and \p{Ll} match all
+in the release at the time of writing (5.32), \p{Lu} and \p{Ll} match all
 letters, regardless of case, when case independence is specified.
 </P>
 <P>
+16. From release 5.32.0, Perl locks out the use of \K in lookaround 
+assertions. In PCRE2, \K is acted on when it occurs in positive assertions, 
+but is ignored in negative assertions.
+</P>
+<P>
 17. PCRE2 provides some extensions to the Perl regular expression facilities.
-Perl 5.10 includes new features that are not in earlier versions of Perl, some
+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 5.26:
+list is with respect to Perl 5.32:
 <br>
 <br>
 (a) Although lookbehind assertions in PCRE2 must match fixed length strings,
-each alternative branch of a lookbehind assertion can match a different length
-of string. Perl requires them all to have the same length.
+each alternative toplevel branch of a lookbehind assertion can match a
+different length of string. Perl requires them all to have the same length.
 <br>
 <br>
 (b) From PCRE2 10.23, backreferences to groups of fixed length are supported
@@ -203,7 +210,7 @@
 <br>
 <br>
 (l) PCRE2 recognizes some special sequences such as (*CR) or (*NO_JIT) at
-the start of a pattern that set overall options that cannot be changed within
+the start of a pattern. These set overall options that cannot be changed within
 the pattern.
 <br>
 <br>
@@ -239,7 +246,7 @@
 REVISION
 </b><br>
 <P>
-Last updated: 13 July 2019
+Last updated: 06 October 2020
 <br>
 Copyright &copy; 1997-2019 University of Cambridge.
 <br>


Modified: code/trunk/doc/html/pcre2pattern.html
===================================================================
--- code/trunk/doc/html/pcre2pattern.html    2020-10-06 08:04:40 UTC (rev 1276)
+++ code/trunk/doc/html/pcre2pattern.html    2020-10-07 16:27:20 UTC (rev 1277)
@@ -289,8 +289,11 @@
   The quick brown fox
 </pre>
 matches a portion of a subject string that is identical to itself. When
-caseless matching is specified (the PCRE2_CASELESS option), letters are matched
-independently of case.
+caseless matching is specified (the PCRE2_CASELESS option or (?i) within the
+pattern), letters are matched independently of case. Note that there are two
+ASCII characters, K and S, that, in addition to their lower case ASCII
+equivalents, are case-equivalent with Unicode U+212A (Kelvin sign) and U+017F
+(long S) respectively when either PCRE2_UTF or PCRE2_UCP is set.
 </P>
 <P>
 The power of regular expressions comes from the ability to include wild cards,
@@ -326,6 +329,20 @@
   [      POSIX character class (if followed by POSIX syntax)
   ]      terminates the character class
 </pre>
+If a pattern is compiled with the PCRE2_EXTENDED option, most white space in
+the pattern, other than in a character class, and characters between a #
+outside a character class and the next newline, inclusive, are ignored. An
+escaping backslash can be used to include a white space or a # character as
+part of the pattern. If the PCRE2_EXTENDED_MORE option is set, the same
+applies, 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. Option settings can be changed within a pattern; see the 
+section entitled
+<a href="#internaloptions">"Internal Option Setting"</a>
+below.
+</P>
+<P>
 The following sections describe the use of each of the metacharacters.
 </P>
 <br><a name="SEC5" href="#TOC1">BACKSLASH</a><br>
@@ -343,18 +360,11 @@
 In particular, if you want to match a backslash, you write \\.
 </P>
 <P>
-In a UTF mode, only ASCII digits and letters have any special meaning after a
-backslash. All other characters (in particular, those whose code points are
-greater than 127) are treated as literals.
+Only ASCII digits and letters have any special meaning after a backslash. All
+other characters (in particular, those whose code points are greater than 127)
+are treated as literals.
 </P>
 <P>
-If a pattern is compiled with the PCRE2_EXTENDED option, most white space in
-the pattern (other than in a character class), and characters between a #
-outside a character class and the next newline, inclusive, are ignored. An
-escaping backslash can be used to include a white space or # character as part
-of the pattern.
-</P>
-<P>
 If you want to treat all characters in a sequence as literals, you can do so by
 putting them between \Q and \E. This is different from Perl in that $ and @
 are handled as literals in \Q...\E sequences in PCRE2, whereas in Perl, $ and
@@ -1165,8 +1175,9 @@
 matches "foobar", the first substring is still set to "foo".
 </P>
 <P>
-Perl documents that the use of \K within assertions is "not well defined". In
-PCRE2, \K is acted upon when it occurs inside positive assertions, but is
+Perl used to document that the use of \K within lookaround assertions is "not
+well defined", but from version 5.32.0 Perl does not support this usage at all.
+In PCRE2, \K is acted upon when it occurs inside positive assertions, but is
 ignored in negative assertions. Note that when a pattern such as (?=ab\K)
 matches, the reported start of the match can be greater than the end of the
 match. Using \K in a lookbehind assertion at the start of a pattern can also
@@ -1443,7 +1454,10 @@
 \N{U+hh..} in the usual way. When caseless matching is set, any letters in a
 class represent both their upper case and lower case versions, so for example,
 a caseless [aeiou] matches "A" as well as "a", and a caseless [^aeiou] does not
-match "A", whereas a caseful version would.
+match "A", whereas a caseful version would. Note that there are two ASCII
+characters, K and S, that, in addition to their lower case ASCII equivalents,
+are case-equivalent with Unicode U+212A (Kelvin sign) and U+017F (long S)
+respectively when either PCRE2_UTF or PCRE2_UCP is set.
 </P>
 <P>
 Characters that might indicate line breaks are never treated in any special way
@@ -3838,7 +3852,7 @@
 </P>
 <br><a name="SEC32" href="#TOC1">REVISION</a><br>
 <P>
-Last updated: 24 February 2020
+Last updated: 06 October 2020
 <br>
 Copyright &copy; 1997-2020 University of Cambridge.
 <br>


Modified: code/trunk/doc/pcre2.txt
===================================================================
--- code/trunk/doc/pcre2.txt    2020-10-06 08:04:40 UTC (rev 1276)
+++ code/trunk/doc/pcre2.txt    2020-10-07 16:27:20 UTC (rev 1277)
@@ -1463,188 +1463,191 @@
        it  can be changed within a pattern by a (?i) option setting. If either
        PCRE2_UTF or PCRE2_UCP is set, Unicode  properties  are  used  for  all
        characters  with more than one other case, and for all characters whose
-       code points are greater than U+007F. For lower valued  characters  with
-       only  one  other  case,  a lookup table is used for speed. When neither
-       PCRE2_UTF nor PCRE2_UCP is set, a lookup table is  used  for  all  code
-       points  less than 256, and higher code points (available only in 16-bit
-       or 32-bit mode) are treated as not having another case.
+       code points are greater than U+007F. Note  that  there  are  two  ASCII
+       characters, K and S, that, in addition to their lower case ASCII equiv-
+       alents, are case-equivalent with U+212A (Kelvin sign) and U+017F  (long
+       S)  respectively. For lower valued characters with only one other case,
+       a lookup table is used for speed. When neither PCRE2_UTF nor  PCRE2_UCP
+       is  set,  a lookup table is used for all code points less than 256, and
+       higher code points (available  only  in  16-bit  or  32-bit  mode)  are
+       treated as not having another case.


          PCRE2_DOLLAR_ENDONLY


-       If this bit is set, a dollar metacharacter in the pattern matches  only
-       at  the  end  of the subject string. Without this option, a dollar also
-       matches immediately before a newline at the end of the string (but  not
-       before  any other newlines). The PCRE2_DOLLAR_ENDONLY option is ignored
-       if PCRE2_MULTILINE is set. There is no equivalent  to  this  option  in
+       If  this bit is set, a dollar metacharacter in the pattern matches only
+       at the end of the subject string. Without this option,  a  dollar  also
+       matches  immediately before a newline at the end of the string (but not
+       before any other newlines). The PCRE2_DOLLAR_ENDONLY option is  ignored
+       if  PCRE2_MULTILINE  is  set.  There is no equivalent to this option in
        Perl, and no way to set it within a pattern.


          PCRE2_DOTALL


-       If  this  bit  is  set,  a dot metacharacter in the pattern matches any
-       character, including one that indicates a  newline.  However,  it  only
+       If this bit is set, a dot metacharacter  in  the  pattern  matches  any
+       character,  including  one  that  indicates a newline. However, it only
        ever matches one character, even if newlines are coded as CRLF. Without
        this option, a dot does not match when the current position in the sub-
-       ject  is  at  a newline. This option is equivalent to Perl's /s option,
+       ject is at a newline. This option is equivalent to  Perl's  /s  option,
        and it can be changed within a pattern by a (?s) option setting. A neg-
-       ative  class such as [^a] always matches newline characters, and the \N
-       escape sequence always matches a non-newline character, independent  of
+       ative class such as [^a] always matches newline characters, and the  \N
+       escape  sequence always matches a non-newline character, independent of
        the setting of PCRE2_DOTALL.


          PCRE2_DUPNAMES


-       If  this  bit is set, names used to identify capture groups need not be
-       unique.  This can be helpful for certain types of pattern  when  it  is
-       known  that  only  one instance of the named group can ever be matched.
-       There are more details of named capture  groups  below;  see  also  the
+       If this bit is set, names used to identify capture groups need  not  be
+       unique.   This  can  be helpful for certain types of pattern when it is
+       known that only one instance of the named group can  ever  be  matched.
+       There  are  more  details  of  named capture groups below; see also the
        pcre2pattern documentation.


          PCRE2_ENDANCHORED


-       If  this  bit is set, the end of any pattern match must be right at the
+       If this bit is set, the end of any pattern match must be right  at  the
        end of the string being searched (the "subject string"). If the pattern
        match succeeds by reaching (*ACCEPT), but does not reach the end of the
-       subject, the match fails at the current starting point. For  unanchored
-       patterns,  a  new  match is then tried at the next starting point. How-
+       subject,  the match fails at the current starting point. For unanchored
+       patterns, a new match is then tried at the next  starting  point.  How-
        ever, if the match succeeds by reaching the end of the pattern, but not
-       the  end  of  the subject, backtracking occurs and an alternative match
+       the end of the subject, backtracking occurs and  an  alternative  match
        may be found. Consider these two patterns:


          .(*ACCEPT)|..
          .|..


-       If matched against "abc" with PCRE2_ENDANCHORED set, the first  matches
-       "c"  whereas  the  second matches "bc". The effect of PCRE2_ENDANCHORED
-       can also be achieved by appropriate constructs in the  pattern  itself,
+       If  matched against "abc" with PCRE2_ENDANCHORED set, the first matches
+       "c" whereas the second matches "bc". The  effect  of  PCRE2_ENDANCHORED
+       can  also  be achieved by appropriate constructs in the pattern itself,
        which is the only way to do it in Perl.


        For DFA matching with pcre2_dfa_match(), PCRE2_ENDANCHORED applies only
-       to the first (that is, the  longest)  matched  string.  Other  parallel
-       matches,  which are necessarily substrings of the first one, must obvi-
+       to  the  first  (that  is,  the longest) matched string. Other parallel
+       matches, which are necessarily substrings of the first one, must  obvi-
        ously end before the end of the subject.


          PCRE2_EXTENDED


-       If this bit is set, most white space characters in the pattern are  to-
+       If  this bit is set, most white space characters in the pattern are to-
        tally ignored except when escaped or inside a character class. However,
-       white space is not allowed within sequences such as (?> that  introduce
-       various  parenthesized groups, nor within numerical quantifiers such as
+       white  space is not allowed within sequences such as (?> that introduce
+       various parenthesized groups, nor within numerical quantifiers such  as
        {1,3}. Ignorable white space is permitted between an item and a follow-
-       ing  quantifier  and  between a quantifier and a following + that indi-
+       ing quantifier and between a quantifier and a following  +  that  indi-
        cates possessiveness. 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
+       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
+       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-
+       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
+       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
+       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
+       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,  un-
-       escaped  space and horizontal tab characters are ignored inside a char-
-       acter class. Note: only these two characters are ignored, not the  full
-       set  of pattern white space characters that are ignored outside a char-
-       acter class. PCRE2_EXTENDED_MORE is equivalent to  Perl's  /xx  option,
+       This  option  has  the  effect of PCRE2_EXTENDED, but, in addition, un-
+       escaped space and horizontal tab characters are ignored inside a  char-
+       acter  class. Note: only these two characters are ignored, not the full
+       set of pattern white space characters that are ignored outside a  char-
+       acter  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


        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_MATCH_INVALID_UTF,  PCRE2_NO_START_OPTIMIZE,  PCRE2_NO_UTF_CHECK,
-       PCRE2_UTF,  and  PCRE2_USE_OFFSET_LIMIT.  The  extra  options PCRE2_EX-
+       PCRE2_UTF, and  PCRE2_USE_OFFSET_LIMIT.  The  extra  options  PCRE2_EX-
        TRA_MATCH_LINE and PCRE2_EXTRA_MATCH_WORD are also supported. Any other
        options cause an error.


          PCRE2_MATCH_INVALID_UTF


-       This  option  forces PCRE2_UTF (see below) and also enables support for
-       matching by pcre2_match() in subject strings that contain  invalid  UTF
-       sequences.   This  facility  is not supported for DFA matching. For de-
+       This option forces PCRE2_UTF (see below) and also enables  support  for
+       matching  by  pcre2_match() in subject strings that contain invalid UTF
+       sequences.  This facility is not supported for DFA  matching.  For  de-
        tails, see the pcre2unicode documentation.


          PCRE2_MATCH_UNSET_BACKREF


-       If this option is set,  a  backreference  to  an  unset  capture  group
-       matches  an  empty  string (by default this causes the current matching
+       If  this  option  is  set,  a  backreference  to an unset capture group
+       matches an empty string (by default this causes  the  current  matching
        alternative to fail).  A pattern such as (\1)(a) succeeds when this op-
-       tion  is  set  (assuming it can find an "a" in the subject), whereas it
-       fails by default, for Perl compatibility.  Setting  this  option  makes
+       tion 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  ($) matches only at the end of the
-       string, or before a terminating newline (except  when  PCRE2_DOLLAR_EN-
+       By default, for the purposes of matching "start of line"  and  "end  of
+       line",  PCRE2  treats the subject string as consisting of a single line
+       of characters, even if it actually contains  newlines.  The  "start  of
+       line"  metacharacter  (^)  matches only at the start of the string, and
+       the "end of line" metacharacter ($) matches only  at  the  end  of  the
+       string,  or  before a terminating newline (except when PCRE2_DOLLAR_EN-
        DONLY is set). Note, however, that unless PCRE2_DOTALL is set, the "any
-       character" metacharacter (.) does not match at a newline.  This  behav-
+       character"  metacharacter  (.) does not match at a newline. This behav-
        iour (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
+       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 ap-
        plications that process patterns from external sources. Note that there
        is also a build-time option that permanently locks out the use of \C.
@@ -1651,20 +1654,20 @@


          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  ap-
+       vents the creator of the pattern from switching to  UTF  interpretation
+       by  starting  the pattern with (*UTF). This option may be useful in ap-
        plications that process patterns from external sources. The combination
        of PCRE2_UTF and PCRE2_NEVER_UTF causes an error.


@@ -1671,122 +1674,122 @@
          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  capture  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 capture 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
+       .*  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 capture group that is the subject of a backreference,
-       or if the pattern contains (*PRUNE) or (*SKIP). When  the  optimization
-       is   not   disabled,  such  a  pattern  is  automatically  anchored  if
+       or  if  the pattern contains (*PRUNE) or (*SKIP). When the optimization
+       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 re-
+       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  re-
        sult is "no match".


-       As another start-up optimization makes use of a minimum  length  for  a
+       As  another  start-up  optimization makes use of a minimum length for a
        matching subject, which is recorded when possible. Consider the pattern


          (*MARK:1)B(*MARK:2)(X|Y)


-       The  minimum  length  for  a match is two characters. If the subject is
+       The minimum length for a match is two characters.  If  the  subject  is
        "XXBB", the "starting character" optimization skips "XX", then tries to
-       match  "BB", which is long enough. In the process, (*MARK:2) is encoun-
-       tered and remembered. When the match attempt fails,  the  next  "B"  is
-       found,  but  there is only one character left, so there are no more at-
-       tempts, and "no match" is returned with the "last  mark  seen"  set  to
-       "2".  If  NO_START_OPTIMIZE is set, however, matches are tried at every
-       possible starting position, including at the end of the subject,  where
-       (*MARK:1)  is encountered, but there is no "B", so the "last mark seen"
-       that is returned is "1". In this case, the optimizations do not  affect
+       match "BB", which is long enough. In the process, (*MARK:2) is  encoun-
+       tered  and  remembered.  When  the match attempt fails, the next "B" is
+       found, but there is only one character left, so there are no  more  at-
+       tempts,  and  "no  match"  is returned with the "last mark seen" set to
+       "2". If NO_START_OPTIMIZE is set, however, matches are tried  at  every
+       possible  starting position, including at the end of the subject, where
+       (*MARK:1) is encountered, but there is no "B", so the "last mark  seen"
+       that  is returned is "1". In this case, the optimizations do not affect
        the overall match result, which is still "no match", but they do 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
+       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 in-
-       valid  UTF  string as a pattern is undefined. It may cause your program
+       valid 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.


@@ -1793,132 +1796,132 @@
          PCRE2_UCP


        This option has two effects. Firstly, it change 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
+       \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 char-
-       acters. More details are given in  the  section  on  generic  character
-       types  in  the pcre2pattern page. If you set PCRE2_UCP, matching one of
+       acters.  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 second effect of PCRE2_UCP is to force the use of  Unicode  proper-
-       ties  for  upper/lower casing operations on characters with code points
-       greater than 127, even when PCRE2_UTF is not set. This makes it  possi-
+       The  second  effect of PCRE2_UCP is to force the use of Unicode proper-
+       ties for upper/lower casing operations on characters with  code  points
+       greater  than 127, even when PCRE2_UTF is not set. This makes it possi-
        ble, for example, to process strings in the 16-bit UCS-2 code. This op-
-       tion is available only if PCRE2 has been compiled with Unicode  support
+       tion  is available only if PCRE2 has been compiled with Unicode support
        (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 de-
-       scription 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  de-
+       scription  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
+       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. De-
-       tails of how PCRE2_UTF changes the behaviour of PCRE2 are given in  the
+       tails  of how PCRE2_UTF changes the behaviour of PCRE2 are given in the
        pcre2unicode  page.  In  particular,  note  that  it  changes  the  way
        PCRE2_CASELESS handles characters with code points greater than 127.


    Extra compile options


-       The option bits that can be set in a compile  context  by  calling  the
+       The  option  bits  that  can be set in a compile 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, ex-
-       plicitly   test   for   the  surrogates  using  escape  sequences.  The
-       PCRE2_NO_UTF_CHECK option does not disable the error that  occurs,  be-
+       plicitly  test  for  the  surrogates  using   escape   sequences.   The
+       PCRE2_NO_UTF_CHECK  option  does not disable the error that occurs, be-
        cause it applies only to the testing of input strings for UTF validity.


-       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_ALT_BSUX


-       The  original option PCRE2_ALT_BSUX causes PCRE2 to process \U, \u, and
-       \x in the way that ECMAscript (aka JavaScript) does.  Additional  func-
+       The original option PCRE2_ALT_BSUX causes PCRE2 to process \U, \u,  and
+       \x  in  the way that ECMAscript (aka JavaScript) does. Additional func-
        tionality was defined by ECMAscript 6; setting PCRE2_EXTRA_ALT_BSUX has
-       the effect of PCRE2_ALT_BSUX, but in addition it  recognizes  \u{hhh..}
+       the  effect  of PCRE2_ALT_BSUX, but in addition it recognizes \u{hhh..}
        as a hexadecimal character code, where hhh.. is any number of hexadeci-
        mal digits.


          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  malformed  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  op-
+       If the PCRE2_EXTRA_BAD_ESCAPE_IS_LITERAL  extra  option  is  passed  to
+       pcre2_compile(),  all  unrecognized  or  malformed 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 op-
        tion means that typos in patterns may go undetected and have unexpected
-       results. Also note that a sequence such as [\N{] is  interpreted  as  a
-       malformed  attempt  at [\N{...}] and so is treated as [N{] whereas [\N]
+       results.  Also  note  that a sequence such as [\N{] is interpreted as a
+       malformed attempt at [\N{...}] and so is treated as [N{]  whereas  [\N]
        gives an error because an unqualified \N is a valid escape sequence but
-       is  not supported in a character class. To reiterate: this is a danger-
+       is not supported in a character class. To reiterate: this is a  danger-
        ous option. Use with great care.


          PCRE2_EXTRA_ESCAPED_CR_IS_LF


-       There are some legacy applications where the escape sequence  \r  in  a
-       pattern  is expected to match a newline. If this option is set, \r in a
-       pattern is converted to \n so that it matches a LF  (linefeed)  instead
-       of  a CR (carriage return) character. The option does not affect a lit-
-       eral CR in the pattern, nor does it affect CR specified as an  explicit
+       There  are  some  legacy applications where the escape sequence \r in a
+       pattern is expected to match a newline. If this option is set, \r in  a
+       pattern  is  converted to \n so that it matches a LF (linefeed) instead
+       of a CR (carriage return) character. The option does not affect a  lit-
+       eral  CR in the pattern, nor does it affect CR specified as an explicit
        code point such as \x{0D}.


          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 ")$" at the end. Thus, when PCRE2_MULTILINE  is  set,
-       the  matched  line may be in the middle of the subject string. This op-
+       This option is provided for use by  the  -x  option  of  pcre2grep.  It
+       causes  the  pattern  only to match complete lines. This is achieved by
+       automatically inserting the code for "^(?:" at the start  of  the  com-
+       piled  pattern  and ")$" at the end. Thus, when PCRE2_MULTILINE is set,
+       the matched line may be in the middle of the subject string.  This  op-
        tion 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.



@@ -1941,16 +1944,16 @@

        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.



@@ -1961,46 +1964,46 @@
        void pcre2_maketables_free(pcre2_general_context *gcontext,
          const uint8_t *tables);


-       PCRE2  handles caseless matching, and determines whether characters are
-       letters, digits, or whatever, by reference to a set of tables,  indexed
+       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. However, this applies only to characters whose
-       code points are less than 256. By default,  higher-valued  code  points
+       code  points  are  less than 256. By default, higher-valued code points
        never match escapes such as \w or \d.


-       When  PCRE2  is  built  with Unicode support (the default), the Unicode
+       When PCRE2 is built with Unicode support  (the  default),  the  Unicode
        properties of 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
-       the  built-in  tables.  PCRE2_UCP also causes upper/lower casing opera-
-       tions on characters with code points greater than 127  to  use  Unicode
+       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.  PCRE2_UCP also causes upper/lower  casing  opera-
+       tions  on  characters  with code points greater than 127 to use Unicode
        properties. These effects apply even when PCRE2_UTF is not set.


-       The  use  of  locales  with Unicode is discouraged. If you are handling
-       characters with code points greater than 127,  you  should  either  use
+       The use of locales with Unicode is discouraged.  If  you  are  handling
+       characters  with  code  points  greater than 127, you should either use
        Unicode support, or use locales, but not try to mix the two.


-       PCRE2  contains a built-in set of character tables that are used by de-
-       fault.  These are sufficient for many applications. Normally,  the  in-
-       ternal  tables  recognize only ASCII characters. However, when PCRE2 is
+       PCRE2 contains a built-in set of character tables that are used by  de-
+       fault.   These  are sufficient for many applications. Normally, the in-
+       ternal 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 built-in 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  built-in 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,
+       External tables are built by calling the  pcre2_maketables()  function,
        in the relevant locale. The only argument to this function is a general
-       context,  which  can  be used to pass a custom memory allocator. If the
+       context, which can be used to pass a custom memory  allocator.  If  the
        argument is NULL, the system malloc() is used. 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
+       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  127
+       For example, to build and use  tables  that  are  appropriate  for  the
+       French  locale  (where accented characters with values greater than 127
        are treated as letters), the following code could be used:


          setlocale(LC_CTYPE, "fr_FR");
@@ -2009,31 +2012,31 @@
          pcre2_set_character_tables(ccontext, tables);
          re = pcre2_compile(..., ccontext);


-       The  locale  name "fr_FR" is used on Linux and other Unix-like systems;
+       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".


        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 the
-       matching functions. Thus,  for  any  single  pattern,  compilation  and
-       matching  both happen in the same locale, but different patterns can be
+       matching  functions.  Thus,  for  any  single  pattern, compilation and
+       matching both happen in the same locale, but different patterns can  be
        processed in different locales.


-       It is the caller's responsibility to ensure that the memory  containing
+       It  is the caller's responsibility to ensure that the memory containing
        the tables remains available while they are still in use. When they are
-       no longer needed, you can discard them  using  pcre2_maketables_free(),
-       which  should  pass as its first parameter the same global context that
+       no  longer  needed, you can discard them using pcre2_maketables_free(),
+       which should pass as its first parameter the same global  context  that
        was used to create the tables.


    Saving locale tables


-       The tables described above are just a sequence of binary  bytes,  which
-       makes  them  independent of hardware characteristics such as endianness
-       or whether the processor is 32-bit or 64-bit. A copy of the  result  of
-       pcre2_maketables()  can  therefore  be saved in a file or elsewhere and
-       re-used later, even in a different program or on another computer.  The
-       size  of  the  tables  (number  of  bytes)  must be obtained by calling
-       pcre2_config()  with  the  PCRE2_CONFIG_TABLES_LENGTH  option   because
-       pcre2_maketables()   does   not   return  this  value.  Note  that  the
+       The  tables  described above are just a sequence of binary bytes, which
+       makes them independent of hardware characteristics such  as  endianness
+       or  whether  the processor is 32-bit or 64-bit. A copy of the result of
+       pcre2_maketables() can therefore be saved in a file  or  elsewhere  and
+       re-used  later, even in a different program or on another computer. The
+       size of the tables (number  of  bytes)  must  be  obtained  by  calling
+       pcre2_config()   with  the  PCRE2_CONFIG_TABLES_LENGTH  option  because
+       pcre2_maketables()  does  not  return  this  value.   Note   that   the
        pcre2_dftables program, which is part of the PCRE2 build system, can be
        used stand-alone to create a file that contains a set of binary tables.
        See the pcre2build documentation for details.
@@ -2043,13 +2046,13 @@


        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  re-
-       ceive  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 re-
+       ceive 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:
@@ -2060,8 +2063,8 @@
          PCRE2_ERROR_UNSET          the requested field is not set


        The "magic number" is placed at the start of each compiled pattern as a
-       simple check against passing an arbitrary memory  pointer.  Here  is  a
-       typical  call of pcre2_pattern_info(), to obtain the length of the com-
+       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;
@@ -2079,22 +2082,22 @@
          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  op-
-       tions  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 op-
+       tions 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_EX-
-       TENDED  option,  the result for PCRE2_INFO_ALLOPTIONS is PCRE2_EXTENDED
-       and PCRE2_UTF.  Option settings such as (?i) that can change  within  a
+       For  example, if the pattern /(*UTF)abc/ is compiled with the PCRE2_EX-
+       TENDED 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_ALLOPTIONS, even if they
-       appear right at the start of the pattern. (This was different  in  some
+       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:


@@ -2103,7 +2106,7 @@
          \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
@@ -2113,15 +2116,15 @@
          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  a  uint32_t  variable.  Named  capture
-       groups  acquire  numbers  as well as names, and these count towards the
-       highest backreference. Backreferences such as \4 or  \g{12}  match  the
+       Return the number of the highest  backreference  in  the  pattern.  The
+       third  argument  should  point  to  a  uint32_t variable. Named capture
+       groups 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 capture group is set in a conditional group such as (?(3)a|b) is also
        a backreference.  Zero is returned if there are no backreferences.
@@ -2128,56 +2131,56 @@


          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 capture group number in  the  pattern.  In  patterns
+       Return  the  highest  capture  group number in the pattern. In patterns
        where (?| is not used, this is also the total number of capture groups.
        The third argument should point to a 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 PCRE2_ER-
+       been set, the call to pcre2_pattern_info() returns the error  PCRE2_ER-
        ROR_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
+       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  a  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 a 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 a 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 a 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.


@@ -2184,8 +2187,8 @@
          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 capture group adds two PCRE2_SIZE vari-
        ables.
@@ -2192,15 +2195,15 @@


          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 a uint32_t variable.


          PCRE2_INFO_HASCRORLF


-       Return 1 if the pattern contains any explicit  matches  for  CR  or  LF
-       characters,  otherwise 0. The third argument should point to a 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 se-
+       Return  1  if  the  pattern  contains any explicit matches for CR or LF
+       characters, otherwise 0. The third argument should point to a  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  se-
        quences.


          PCRE2_INFO_HEAPLIMIT
@@ -2208,45 +2211,45 @@
        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  a  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 a 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
+       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 a 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
+       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
+       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 a uint32_t variable.


          PCRE2_INFO_MATCHEMPTY


-       Return  1  if the pattern might match an empty string, otherwise 0. The
+       Return 1 if the pattern might match an empty string, otherwise  0.  The
        third argument should point to a uint32_t variable. When a pattern con-
        tains recursive subroutine calls it is not always possible to determine
        whether or not it can match an empty string. PCRE2 takes a cautious ap-
@@ -2254,44 +2257,44 @@


          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  ar-
-       gument  should  point  to a uint32_t integer. If no such value has been
+       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 ar-
+       gument 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_UN-
-       SET.  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  func-
+       SET. 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 func-
        tion.


          PCRE2_INFO_MAXLOOKBEHIND


-       A  lookbehind  assertion moves back a certain number of characters (not
-       code units) when it starts to process each of its  branches.  This  re-
-       quest  returns  the largest of these backward moves. The third argument
+       A lookbehind assertion moves back a certain number of  characters  (not
+       code  units)  when  it starts to process each of its branches. This re-
+       quest returns the largest of these backward moves. The  third  argument
        should point to a uint32_t integer. The simple assertions \b and \B re-
-       quire  a one-character lookbehind and cause PCRE2_INFO_MAXLOOKBEHIND to
-       return 1 in the absence of anything longer. \A also  registers  a  one-
-       character  lookbehind, though it does not actually inspect the previous
+       quire a one-character lookbehind and cause PCRE2_INFO_MAXLOOKBEHIND  to
+       return  1  in  the absence of anything longer. \A also registers a one-
+       character lookbehind, though it does not actually inspect the  previous
        character.


        Note that this information is useful for multi-segment matching only if
-       the  pattern  contains  no nested lookbehinds. For example, the pattern
-       (?<=a(?<=ba)c) returns a maximum lookbehind of 2, but when it  is  pro-
-       cessed,  the first lookbehind moves back by two characters, matches one
-       character, then the nested lookbehind also moves back  by  two  charac-
+       the pattern contains no nested lookbehinds. For  example,  the  pattern
+       (?<=a(?<=ba)c)  returns  a maximum lookbehind of 2, but when it is pro-
+       cessed, the first lookbehind moves back by two characters, matches  one
+       character,  then  the  nested lookbehind also moves back by two charac-
        ters. This puts the matching point three characters earlier than it was
-       at the start.  PCRE2_INFO_MAXLOOKBEHIND is really only useful as a  de-
-       bugging  tool.  See  the pcre2partial documentation for a discussion of
+       at  the start.  PCRE2_INFO_MAXLOOKBEHIND is really only useful as a de-
+       bugging tool. See the pcre2partial documentation for  a  discussion  of
        multi-segment matching.


          PCRE2_INFO_MINLENGTH


-       If a minimum length for matching  subject  strings  was  computed,  its
+       If  a  minimum  length  for  matching subject strings was computed, its
        value is returned. Otherwise the returned value is 0. This value is not
-       computed when PCRE2_NO_START_OPTIMIZE is set. The value is a number  of
-       characters,  which in UTF mode may be different from the number of code
-       units. The third argument should point  to  a  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
+       computed  when PCRE2_NO_START_OPTIMIZE is set. The value is a number of
+       characters, which in UTF mode may be different from the number of  code
+       units.  The  third  argument  should  point to a 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
@@ -2299,44 +2302,44 @@
          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
+       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 de-
        scribed 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 li-
-       brary, the first two bytes of each entry are the number of the  captur-
-       ing  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.
+       brary,  the first two bytes of each entry are the number of the captur-
+       ing 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 rest of the entry is the corresponding name, zero terminated.


-       The  names are in alphabetical order. If (?| is used to create multiple
+       The names are in alphabetical order. If (?| is used to create  multiple
        capture groups with the same number, as described in the section on du-
        plicate group numbers in the pcre2pattern page, the groups may be given
-       the same name, but there is only one  entry  in  the  table.  Different
+       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 capture groups with different numbers are permit-
+       Duplicate names for capture groups with different numbers  are  permit-
        ted, 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 capture groups may have lower num-
+       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 capture groups may have  lower  num-
        bers.


-       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):


          (?<date> (?<year>(\d\d)?\d\d) -
@@ -2343,7 +2346,7 @@
          (?<month>\d\d) - (?<day>\d\d) )


        There are four named capture groups, so the table has four entries, and
-       each  entry  in the table is eight bytes long. The table is as follows,
+       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 ??:


@@ -2352,8 +2355,8 @@
          00 04 m  o  n  t  h  00
          00 02 y  e  a  r  00 ??


-       When  writing  code to extract data from named capture groups using the
-       name-to-number map, remember that the length of the entries  is  likely
+       When writing code to extract data from named capture groups  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
@@ -2372,14 +2375,14 @@


          PCRE2_INFO_SIZE


-       Return the size of the compiled pattern in bytes  (for  all  three  li-
-       braries).  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-
+       Return  the  size  of  the compiled pattern in bytes (for all three li-
+       braries). 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, be-
-       cause there are cases where the code that calculates the  size  has  to
-       over-estimate.  Processing a pattern with the JIT compiler does not al-
+       cause  there  are  cases where the code that calculates the size has to
+       over-estimate. Processing a pattern with the JIT compiler does not  al-
        ter the value returned by this option.



@@ -2390,30 +2393,30 @@
          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.



@@ -2427,58 +2430,58 @@

        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  re-
-       quired  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
+       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 re-
+       quired 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
        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
-       after a match operation has finished,  using  functions  that  are  de-
+       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 de-
        scribed 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_ER-
-       ROR_PARTIAL,  or  one of the error codes for an invalid UTF string. Ex-
+       When a call of pcre2_match() fails, valid  data  is  available  in  the
+       match  block  only  when  the  error  is PCRE2_ERROR_NOMATCH, PCRE2_ER-
+       ROR_PARTIAL, or one of the error codes for an invalid UTF  string.  Ex-
        actly 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  a  successful
+       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 a successful
        match. 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,  unless,  in  the case of the subject
-       string, you have used the PCRE2_COPY_MATCHED_SUBJECT option,  which  is
-       described  in  the section entitled "Option bits for pcre2_match()" be-
+       subject  string until after all operations on the match data block (for
+       that match) have taken place,  unless,  in  the  case  of  the  subject
+       string,  you  have used the PCRE2_COPY_MATCHED_SUBJECT option, which is
+       described in the section entitled "Option bits for  pcre2_match()"  be-
        low.


-       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.



@@ -2489,15 +2492,15 @@
          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  op-
-       erates  in  a Perl-like manner. For specialist use there is also an al-
-       ternative matching function, which is described below  in  the  section
+       This  function is the main matching facility of the library, and it op-
+       erates in a Perl-like manner. For specialist use there is also  an  al-
+       ternative  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():
@@ -2512,7 +2515,7 @@
            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.
@@ -2519,110 +2522,110 @@


    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 bi-
+       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  bi-
        nary 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,  be-
-       cause  \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
+       finds the first occurrence. If pcre2_match() is called again with  just
+       the  remainder  of the subject, namely "issipi", it does not match, be-
+       cause \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
        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_COPY_MATCHED_SUBJECT,  PCRE2_ENDANCHORED, PCRE2_NOTBOL, PCRE2_NO-
+       The    only    bits    that    may    be    set   are   PCRE2_ANCHORED,
+       PCRE2_COPY_MATCHED_SUBJECT, PCRE2_ENDANCHORED, PCRE2_NOTBOL,  PCRE2_NO-
        TEOL,     PCRE2_NOTEMPTY,     PCRE2_NOTEMPTY_ATSTART,     PCRE2_NO_JIT,
-       PCRE2_NO_UTF_CHECK,  PCRE2_PARTIAL_HARD,  and PCRE2_PARTIAL_SOFT. Their
+       PCRE2_NO_UTF_CHECK, PCRE2_PARTIAL_HARD, and  PCRE2_PARTIAL_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_COPY_MATCHED_SUBJECT


-       By default, a pointer to the subject is remembered in  the  match  data
-       block  so  that,  after a successful match, it can be referenced by the
-       substring extraction functions. This means that  the  subject's  memory
-       must  not be freed until all such operations are complete. For some ap-
-       plications where the lifetime of the subject string is not  guaranteed,
-       it  may  be  necessary  to make a copy of the subject string, but it is
-       wasteful to do this unless the match is successful. After a  successful
-       match,  if PCRE2_COPY_MATCHED_SUBJECT is set, the subject is copied and
-       the new pointer is remembered in the match data block  instead  of  the
-       original  subject  pointer.  The memory allocator that was used for the
-       match block itself is  used.  The  copy  is  automatically  freed  when
-       pcre2_match_data_free()  is  called to free the match data block. It is
+       By  default,  a  pointer to the subject is remembered in the match data
+       block so that, after a successful match, it can be  referenced  by  the
+       substring  extraction  functions.  This means that the subject's memory
+       must not be freed until all such operations are complete. For some  ap-
+       plications  where the lifetime of the subject string is not guaranteed,
+       it may be necessary to make a copy of the subject  string,  but  it  is
+       wasteful  to do this unless the match is successful. After a successful
+       match, if PCRE2_COPY_MATCHED_SUBJECT is set, the subject is copied  and
+       the  new  pointer  is remembered in the match data block instead of the
+       original subject pointer. The memory allocator that was  used  for  the
+       match  block  itself  is  used.  The  copy  is automatically freed when
+       pcre2_match_data_free() is called to free the match data block.  It  is
        also automatically freed if the match data block is re-used for another
        match operation.


          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.


@@ -2629,9 +2632,9 @@
          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.


@@ -2638,67 +2641,67 @@
          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  plus  the  starting offset. An empty string match later in the
        subject is permitted.  If the pattern is anchored, such a match can oc-
        cur 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  unless  PCRE2_NO_UTF_CHECK   is   passed   to
+       UTF   string   is   checked  unless  PCRE2_NO_UTF_CHECK  is  passed  to
        pcre2_match() or PCRE2_MATCH_INVALID_UTF was passed to pcre2_compile().
        The latter special case is discussed in detail in the pcre2unicode doc-
        umentation.


-       In  the default case, if a non-zero starting offset is given, the check
-       is applied only to that part of the subject  that  could  be  inspected
-       during  matching,  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
+       In the default case, if a non-zero starting offset is given, the  check
+       is  applied  only  to  that part of the subject that could be inspected
+       during matching, 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
+       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 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 documentation.


        If you know that your subject is valid, and you want to skip this check
        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
+       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 multiple matches in the same subject string.


-       Warning: Unless PCRE2_MATCH_INVALID_UTF was set at compile  time,  when
-       PCRE2_NO_UTF_CHECK  is  set  at match time the effect of passing an in-
+       Warning:  Unless  PCRE2_MATCH_INVALID_UTF was set at compile time, when
+       PCRE2_NO_UTF_CHECK is set at match time the effect of  passing  an  in-
        valid string as a subject, or an invalid value of startoffset, is unde-
-       fined.   Your  program may crash or loop indefinitely or give wrong re-
+       fined.  Your program may crash or loop indefinitely or give  wrong  re-
        sults.


          PCRE2_PARTIAL_HARD
@@ -2705,22 +2708,22 @@
          PCRE2_PARTIAL_SOFT


        These options turn on the partial matching feature. A partial match oc-
-       curs  if  the  end  of  the subject string is reached successfully, but
+       curs if the end of the subject  string  is  reached  successfully,  but
        there are not enough subject characters to complete the match. In addi-
-       tion,  either  at  least  one character must have been inspected or the
-       pattern must contain a lookbehind, or the  pattern  must  be  one  that
+       tion, either at least one character must have  been  inspected  or  the
+       pattern  must  contain  a  lookbehind,  or the pattern must be one that
        could match an empty string.


-       If  this  situation  arises when PCRE2_PARTIAL_SOFT (but not PCRE2_PAR-
+       If this situation arises when PCRE2_PARTIAL_SOFT  (but  not  PCRE2_PAR-
        TIAL_HARD) is set, matching continues by testing any remaining alterna-
-       tives.  Only  if  no complete match can be found is PCRE2_ERROR_PARTIAL
-       returned instead of PCRE2_ERROR_NOMATCH.  In  other  words,  PCRE2_PAR-
-       TIAL_SOFT  specifies  that  the  caller is prepared to handle a partial
+       tives. Only if no complete match can be  found  is  PCRE2_ERROR_PARTIAL
+       returned  instead  of  PCRE2_ERROR_NOMATCH.  In other words, PCRE2_PAR-
+       TIAL_SOFT specifies that the caller is prepared  to  handle  a  partial
        match, but only if no complete 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.


@@ -2730,38 +2733,38 @@

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 op-
-       tion 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-
+       expected. For example, if the pattern is .+A (and the PCRE2_DOTALL  op-
+       tion  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-
        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.


@@ -2772,82 +2775,82 @@

        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 "capture group" (Perl terminology) is used for a fragment  of  a
-       pattern  that picks out a substring. PCRE2 supports several other kinds
+       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  "capture  group" (Perl terminology) is used for a fragment of a
+       pattern that picks out a substring. PCRE2 supports several other  kinds
        of parenthesized group that do not cause substrings to be captured. The
-       pcre2_pattern_info()  function can be used to find out how many capture
+       pcre2_pattern_info() function can be used to find out how many  capture
        groups 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
+       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 li-
        brary, 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 capture group is matched repeatedly within a single  match  opera-
+       If  a  capture group is matched repeatedly within a single match opera-
        tion, it is the last portion of the subject that it matched that is re-
        turned.


        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 capture group number n+1 to match some part  of  the
-       subject  when  group  n  has  not been used at all. For example, if the
+       It  is  possible for capture group number n+1 to match some part of the
+       subject when group n has not been used at  all.  For  example,  if  the
        string "abc" is matched against the pattern (a|(z))(bc) the return from
-       the  function  is 4, and groups 1 and 3 are matched, but 2 is not. When
-       this happens, both values in the offset pairs corresponding  to  unused
+       the function is 4, and groups 1 and 3 are matched, but 2 is  not.  When
+       this  happens,  both values in the offset pairs corresponding to unused
        groups are set to PCRE2_UNSET.


-       Offset  values  that  correspond to unused groups at the end of the ex-
-       pression are also set to PCRE2_UNSET. For example, if the string  "abc"
-       is  matched  against  the pattern (abc)(x(yz)?)? groups 2 and 3 are not
-       matched. The return from the function is 2, because  the  highest  used
-       capture  group  number  is  1. The offsets for for the second and third
-       capture groupss (assuming the vector is large enough,  of  course)  are
+       Offset values that correspond to unused groups at the end  of  the  ex-
+       pression  are also set to PCRE2_UNSET. For example, if the string "abc"
+       is matched against the pattern (abc)(x(yz)?)? groups 2 and  3  are  not
+       matched.  The  return  from the function is 2, because the highest used
+       capture group number is 1. The offsets for for  the  second  and  third
+       capture  groupss  (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-
-       ously  had.  After  a failed match attempt, the contents of the ovector
+       pcre2_match().  The  other  elements retain whatever values they previ-
+       ously had. After a failed match attempt, the contents  of  the  ovector
        are unchanged.



@@ -2857,25 +2860,25 @@

        PCRE2_SIZE pcre2_get_startchar(pcre2_match_data *match_data);


-       As well as the offsets in the ovector, other information about a  match
-       is  retained  in the match data block and can be retrieved by the above
-       functions in appropriate circumstances. If they  are  called  at  other
+       As  well as the offsets in the ovector, other information about a match
+       is retained in the match data block and can be retrieved by  the  above
+       functions  in  appropriate  circumstances.  If they are called at other
        times, the result is undefined.


-       After  a  successful match, a partial match (PCRE2_ERROR_PARTIAL), or a
-       failure to match (PCRE2_ERROR_NOMATCH), a mark name may  be  available.
-       The  function pcre2_get_mark() can be called to access this name, which
-       can be specified in the pattern by  any  of  the  backtracking  control
+       After a successful match, a partial match (PCRE2_ERROR_PARTIAL),  or  a
+       failure  to  match (PCRE2_ERROR_NOMATCH), a mark name may be available.
+       The function pcre2_get_mark() can be called to access this name,  which
+       can  be  specified  in  the  pattern by any of the backtracking control
        verbs, not just (*MARK). The same function applies to all the 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
+       After  a  successful  match, the name that is returned is the last mark
        name encountered on the matching path through the pattern. Instances of
-       backtracking verbs without names do not count. Thus,  for  example,  if
+       backtracking  verbs  without  names do not count. 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 re-
        turned. For example, consider this pattern:
@@ -2882,30 +2885,30 @@


          ^(*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 en-
+       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  en-
        gine. This check fails for "bx", causing a match failure without seeing
-       any  marks. You can disable the start-of-match optimizations by setting
-       the PCRE2_NO_START_OPTIMIZE option for pcre2_compile() or  by  starting
+       any marks. You can disable the start-of-match optimizations by  setting
+       the  PCRE2_NO_START_OPTIMIZE  option for pcre2_compile() or by 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.


@@ -2912,14 +2915,14 @@

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
@@ -2928,20 +2931,20 @@


          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
@@ -2955,15 +2958,15 @@
          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
@@ -2976,7 +2979,7 @@


          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
@@ -2983,7 +2986,7 @@


        This error is returned when a pattern that was successfully studied us-
        ing JIT is being matched, but the memory available for the just-in-time
-       processing  stack  is  not large enough. See the pcre2jit documentation
+       processing stack is not large enough. See  the  pcre2jit  documentation
        for more details.


          PCRE2_ERROR_MATCHLIMIT
@@ -2992,11 +2995,11 @@


          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
-       the   heap   limit.   PCRE2_ERROR_NOMEMORY   is   also   returned    if
+       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_NOMEMORY   is   also   returned   if
        PCRE2_COPY_MATCHED_SUBJECT is set and memory allocation fails.


          PCRE2_ERROR_NULL
@@ -3005,12 +3008,12 @@


          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 capture group 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
+       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
        groups, cannot be detected until matching is attempted.



@@ -3019,20 +3022,20 @@
        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_ER-
-       ROR_BADDATA is returned. If the buffer is too  small,  the  message  is
+       ROR_BADDATA  is  returned.  If  the buffer is too small, the message 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;
+       PCRE2_ERROR_NOMEMORY  is returned.  None of the messages are very long;
        a buffer size of 120 code units is ample.



@@ -3051,39 +3054,39 @@

        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
        capture group number.


        The final arguments of pcre2_substring_copy_bynumber() are a pointer to
@@ -3092,25 +3095,25 @@
        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 af-
-       ter 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  af-
+       ter  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
@@ -3121,8 +3124,8 @@


          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.



@@ -3133,31 +3136,31 @@

        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), ex-
-       cluding a terminating zero that is added to each of them. All  this  is
+       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),  ex-
+       cluding  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 capture group number n+1 matches some part  of  the  subject,  but
-       group  n has not been used at all, it returns an empty string. This can
+       when  capture  group  number  n+1 matches some part of the subject, but
+       group 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
+       appropriate offset in the ovector, which contain PCRE2_UNSET for  unset
        substrings, or by calling pcre2_substring_length_bynumber().



@@ -3177,7 +3180,7 @@

        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(?<xxx>\d+)...
@@ -3185,32 +3188,32 @@
        the number of the capture group called "xxx" is 2. If the name is known
        to 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
-       the  function  is the group number, PCRE2_ERROR_NOSUBSTRING if there is
-       no group with that name, or PCRE2_ERROR_NOUNIQUESUBSTRING if  there  is
-       more  than one group with that name.  Given the number, you can extract
-       the substring directly from the ovector, or use one of  the  "bynumber"
+       ment  is the compiled pattern, and the second is the name. The yield of
+       the function is the group number, PCRE2_ERROR_NOSUBSTRING if  there  is
+       no  group  with that name, or PCRE2_ERROR_NOUNIQUESUBSTRING if there is
+       more than one group with 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
+       For convenience, there are also "byname" functions that  correspond  to
        the "bynumber" functions, the only difference being that the second ar-
-       gument  is  a  name  instead  of a number. If PCRE2_DUPNAMES is set and
+       gument 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  captured substring from the first named
+       given name, and return the captured  substring  from  the  first  named
        group 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
+       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 re-
-       turned.  If there is at least one group with a slot in the ovector, but
+       turned. 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 capture
-       groups  with  the same number, as described in the section on duplicate
+       groups with the same number, as described in the section  on  duplicate
        group numbers in the pcre2pattern page, you cannot use names to distin-
-       guish  the  different capture groups, because names are not included in
-       the compiled code. The matching process uses  only  numbers.  For  this
-       reason,  the  use  of  different  names for groups with the same number
+       guish the different capture groups, because names are not  included  in
+       the  compiled  code.  The  matching process uses only numbers. For this
+       reason, the use of different names for  groups  with  the  same  number
        causes an error at compile time.



@@ -3223,108 +3226,108 @@
          PCRE2_SIZE rlength, PCRE2_UCHAR *outputbuffer,
          PCRE2_SIZE *outlengthptr);


-       This function optionally calls pcre2_match() and then makes a  copy  of
-       the  subject  string in outputbuffer, replacing parts that were matched
-       with the replacement string, whose length is supplied in rlength.  This
-       can  be  given  as  PCRE2_ZERO_TERMINATED for a zero-terminated string.
+       This  function  optionally calls pcre2_match() and then makes a copy of
+       the subject string in outputbuffer, replacing parts that  were  matched
+       with  the replacement string, whose length is supplied in rlength. This
+       can be given as PCRE2_ZERO_TERMINATED  for  a  zero-terminated  string.
        There is an option (see PCRE2_SUBSTITUTE_REPLACEMENT_ONLY below) to re-
-       turn  just  the replacement string(s). The default action is to perform
-       just one replacement if the pattern matches, but  there  is  an  option
-       that  requests  multiple  replacements (see PCRE2_SUBSTITUTE_GLOBAL be-
+       turn just the replacement string(s). The default action is  to  perform
+       just  one  replacement  if  the pattern matches, but there is an option
+       that requests multiple replacements  (see  PCRE2_SUBSTITUTE_GLOBAL  be-
        low).


-       If successful, pcre2_substitute() returns the number  of  substitutions
-       that  were  carried out. This may be zero if no match was found, and is
-       never greater than one unless PCRE2_SUBSTITUTE_GLOBAL is set.  A  nega-
+       If  successful,  pcre2_substitute() returns the number of substitutions
+       that were carried out. This may be zero if no match was found,  and  is
+       never  greater  than one unless PCRE2_SUBSTITUTE_GLOBAL is set. A nega-
        tive value is returned if an error is detected.


-       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
+       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. For global replacements, matches in which \K in a lookbe-
-       hind causes the match to start earlier than the point that was  reached
+       hind  causes the 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.


-       If match_data is not NULL and PCRE2_SUBSTITUTE_MATCHED is not set,  the
+       If  match_data is not NULL and PCRE2_SUBSTITUTE_MATCHED is not set, the
        provided block is used for all calls to pcre2_match(), and its contents
-       afterwards are the result of the final call. For global  changes,  this
+       afterwards  are  the result of the final call. For global changes, this
        will always be a no-match error. The contents of the ovector within the
        match data block may or may not have been changed.


-       As well as the usual options for pcre2_match(), a number of  additional
-       options  can be set in the options argument of pcre2_substitute().  One
-       such option is PCRE2_SUBSTITUTE_MATCHED. When this is set, an  external
-       match_data  block  must  be provided, and it must have been used for an
-       external call to pcre2_match(). The data in the match_data  block  (re-
+       As  well as the usual options for pcre2_match(), a number of additional
+       options can be set in the options argument of pcre2_substitute().   One
+       such  option is PCRE2_SUBSTITUTE_MATCHED. When this is set, an external
+       match_data block must be provided, and it must have been  used  for  an
+       external  call  to pcre2_match(). The data in the match_data block (re-
        turn code, offset vector) is used for the first substitution instead of
-       calling pcre2_match() from within pcre2_substitute().  This  allows  an
+       calling  pcre2_match()  from  within pcre2_substitute(). This allows an
        application to check for a match before choosing to substitute, without
        having to repeat the match.


-       The contents of the  externally  supplied  match  data  block  are  not
-       changed   when   PCRE2_SUBSTITUTE_MATCHED   is  set.  If  PCRE2_SUBSTI-
-       TUTE_GLOBAL is also set, pcre2_match() is called after the  first  sub-
-       stitution  to  check for further matches, but this is done using an in-
-       ternally obtained match data block, thus always  leaving  the  external
+       The  contents  of  the  externally  supplied  match  data block are not
+       changed  when  PCRE2_SUBSTITUTE_MATCHED  is   set.   If   PCRE2_SUBSTI-
+       TUTE_GLOBAL  is  also set, pcre2_match() is called after the first sub-
+       stitution to check for further matches, but this is done using  an  in-
+       ternally  obtained  match  data block, thus always leaving the external
        block unchanged.


-       The  code  argument is not used for matching before the first substitu-
-       tion when PCRE2_SUBSTITUTE_MATCHED is set, but  it  must  be  provided,
-       even  when  PCRE2_SUBSTITUTE_GLOBAL is not set, because it contains in-
+       The code argument is not used for matching before the  first  substitu-
+       tion  when  PCRE2_SUBSTITUTE_MATCHED  is  set, but it must be provided,
+       even when PCRE2_SUBSTITUTE_GLOBAL is not set, because it  contains  in-
        formation such as the UTF setting and the number of capturing parenthe-
        ses in the pattern.


-       The  default  action  of  pcre2_substitute() is to return a copy of the
+       The default action of pcre2_substitute() is to return  a  copy  of  the
        subject string with matched substrings replaced. However, if PCRE2_SUB-
-       STITUTE_REPLACEMENT_ONLY  is  set,  only the replacement substrings are
+       STITUTE_REPLACEMENT_ONLY is set, only the  replacement  substrings  are
        returned. In the global case, multiple replacements are concatenated in
-       the  output  buffer.  Substitution  callouts (see below) can be used to
+       the output buffer. Substitution callouts (see below)  can  be  used  to
        separate them if necessary.


-       The outlengthptr argument of pcre2_substitute() must point to  a  vari-
-       able  that contains the length, in code units, of the output buffer. If
-       the function is successful, the value is updated to contain the  length
-       in  code  units  of the new string, excluding the trailing zero that is
+       The  outlengthptr  argument of pcre2_substitute() must point to a vari-
+       able that contains the length, in code units, of the output buffer.  If
+       the  function is successful, the value is updated to contain the length
+       in code units of the new string, excluding the trailing  zero  that  is
        automatically added.


-       If the function is not successful, the value set via  outlengthptr  de-
-       pends  on  the  type  of  error.  For  syntax errors in the replacement
+       If  the  function is not successful, the value set via outlengthptr de-
+       pends on the type of  error.  For  syntax  errors  in  the  replacement
        string, the value is the offset in the replacement string where the er-
-       ror  was  detected.  For  other errors, the value is PCRE2_UNSET by de-
+       ror was detected. For other errors, the value  is  PCRE2_UNSET  by  de-
        fault. This includes the case of the output buffer being too small, un-
        less PCRE2_SUBSTITUTE_OVERFLOW_LENGTH is set.


-       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 PCRE2_ER-
+       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_ER-
        ROR_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.


-       The  replacement  string,  which  is interpreted as a UTF string in UTF
-       mode, is checked for UTF validity unless PCRE2_NO_UTF_CHECK is set.  An
+       The replacement string, which is interpreted as a  UTF  string  in  UTF
+       mode,  is checked for UTF validity unless PCRE2_NO_UTF_CHECK is set. An
        invalid UTF replacement string causes an immediate return with the rel-
        evant UTF error code.


-       If PCRE2_SUBSTITUTE_LITERAL is set, the replacement string is  not  in-
+       If  PCRE2_SUBSTITUTE_LITERAL  is set, the replacement string is not in-
        terpreted in any way. By default, however, a dollar character is an es-
-       cape character that can specify the insertion of characters  from  cap-
-       ture  groups  and names from (*MARK) or other control verbs in the pat-
+       cape  character  that can specify the insertion of characters from cap-
+       ture groups and names from (*MARK) or other control verbs in  the  pat-
        tern. The following forms are always recognized:


          $$                  insert a dollar character
@@ -3331,18 +3334,18 @@
          $<n> or ${<n>}      insert the contents of group <n>
          $*MARK or ${*MARK}  insert a control verb name


-       Either a group number or a group name  can  be  given  for  <n>.  Curly
-       brackets  are  required only if the following character would be inter-
+       Either  a  group  number  or  a  group name can be given for <n>. 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 backtracking control
-       verb on the matching path that has a name. (*MARK) must always  include
-       a  name,  but  the  other  verbs  need not. For example, in the case of
+       $*MARK inserts the name from the last encountered backtracking  control
+       verb  on the matching path that has a name. (*MARK) must always include
+       a name, but the other verbs 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
+       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}
@@ -3350,15 +3353,15 @@
           2: pear orange


        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:


@@ -3366,73 +3369,73 @@
          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_UNKNOWN_UNSET causes references to capture 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
+       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 capture groups (including un-
-       known groups when PCRE2_SUBSTITUTE_UNKNOWN_UNSET is set) to be  treated
-       as  empty  strings  when inserted as described above. If this option is
+       known  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_UN-
-       SET  error.  This  option  does not influence the extended substitution
+       SET 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 capture groups and let-
-       ters within \Q...\E quoted sequences. If either PCRE2_UTF or  PCRE2_UCP
-       was  set when the pattern was compiled, Unicode properties are used for
+       all inserted  characters, including those from capture groups and  let-
+       ters  within \Q...\E quoted sequences. If either PCRE2_UTF or PCRE2_UCP
+       was set when the pattern was compiled, Unicode properties are used  for
        case forcing characters whose code points are greater than 127.


        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
-       \E has no effect. Note  also  that  the  PCRE2_ALT_BSUX  and  PCRE2_EX-
+       ple, the result of processing "\Uaa\LBB\Ecc\E" is "AAbbcc";  the  final
+       \E  has  no  effect.  Note  also  that the PCRE2_ALT_BSUX and PCRE2_EX-
        TRA_ALT_BSUX options do not apply to replacement strings.


-       The  second  effect of setting PCRE2_SUBSTITUTE_EXTENDED is to add more
-       flexibility to capture group substitution. The  syntax  is  similar  to
+       The second effect of setting PCRE2_SUBSTITUTE_EXTENDED is to  add  more
+       flexibility  to  capture  group  substitution. The syntax is similar to
        that used by Bash:


          ${<n>:-<string>}
          ${<n>:+<string1>:<string2>}


-       As  before,  <n> may be a group number or a name. The first form speci-
-       fies a default value. If group <n> is set, its value  is  inserted;  if
-       not,  <string>  is  expanded  and  the result inserted. The second form
-       specifies strings that are expanded and inserted when group <n> is  set
-       or  unset,  respectively. The first form is just a convenient shorthand
+       As before, <n> may be a group number or a name. The first  form  speci-
+       fies  a  default  value. If group <n> is set, its value is inserted; if
+       not, <string> is expanded and the  result  inserted.  The  second  form
+       specifies  strings that are expanded and inserted when group <n> is set
+       or unset, respectively. The first form is just a  convenient  shorthand
        for


          ${<n>:+${<n>}:<string>}


-       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
@@ -3441,8 +3444,8 @@
              somebody
           1: HELLO


-       The  PCRE2_SUBSTITUTE_UNSET_EMPTY option does not affect these extended
-       substitutions. However, PCRE2_SUBSTITUTE_UNKNOWN_UNSET does  cause  un-
+       The PCRE2_SUBSTITUTE_UNSET_EMPTY option does not affect these  extended
+       substitutions.  However,  PCRE2_SUBSTITUTE_UNKNOWN_UNSET does cause un-
        known groups in the extended syntax forms to be treated as unset.


        If  PCRE2_SUBSTITUTE_LITERAL  is  set,  PCRE2_SUBSTITUTE_UNKNOWN_UNSET,
@@ -3451,8 +3454,8 @@


    Substitution errors


-       In  the  event of an error, pcre2_substitute() returns a negative error
-       code. Except for PCRE2_ERROR_NOMATCH (which is never returned),  errors
+       In the event of an error, pcre2_substitute() returns a  negative  error
+       code.  Except for 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-
@@ -3459,29 +3462,29 @@
        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)
-       when the simple (non-extended) syntax is used and  PCRE2_SUBSTITUTE_UN-
+       ing an unknown substring when  PCRE2_SUBSTITUTE_UNKNOWN_UNSET  is  set)
+       when  the simple (non-extended) syntax is used and PCRE2_SUBSTITUTE_UN-
        SET_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_NULL is returned if PCRE2_SUBSTITUTE_MATCHED is set but the
        match_data argument is NULL.


-       PCRE2_ERROR_BADREPLACEMENT  is  used for miscellaneous syntax errors in
-       the replacement string, with more  particular  errors  being  PCRE2_ER-
+       PCRE2_ERROR_BADREPLACEMENT is used for miscellaneous syntax  errors  in
+       the  replacement  string,  with  more particular errors being PCRE2_ER-
        ROR_BADREPESCAPE (invalid escape sequence), PCRE2_ERROR_REPMISSINGBRACE
-       (closing curly bracket not found), PCRE2_ERROR_BADSUBSTITUTION  (syntax
-       error  in  extended group substitution), and PCRE2_ERROR_BADSUBSPATTERN
+       (closing  curly bracket not found), PCRE2_ERROR_BADSUBSTITUTION (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, which can happen if \K is
+       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 "Ob-
+       obtained by calling the pcre2_get_error_message()  function  (see  "Ob-
        taining a textual error message" above).


    Substitution callouts
@@ -3490,15 +3493,15 @@
          int (*callout_function)(pcre2_substitute_callout_block *, void *),
          void *callout_data);


-       The pcre2_set_substitution_callout() function can be used to specify  a
-       callout  function for pcre2_substitute(). This information is passed in
+       The  pcre2_set_substitution_callout() function can be used to specify a
+       callout function for pcre2_substitute(). This information is passed  in
        a match context. The callout function is called after each substitution
        has been processed, but it can cause the replacement not to happen. The
-       callout function is not called for simulated substitutions that  happen
+       callout  function is not called for simulated substitutions that happen
        as a result of the PCRE2_SUBSTITUTE_OVERFLOW_LENGTH option.


        The first argument of the callout function is a pointer to a substitute
-       callout block structure, which contains the following fields, not  nec-
+       callout  block structure, which contains the following fields, not nec-
        essarily in this order:


          uint32_t    version;
@@ -3509,9 +3512,9 @@
          uint32_t    oveccount;
          PCRE2_SIZE  output_offsets[2];


-       The  version field contains the version number of the block format. The
-       current version is 0. The version number will  increase  in  future  if
-       more  fields are added, but the intention is never to remove any of the
+       The version field contains the version number of the block format.  The
+       current  version  is  0.  The version number will increase in future if
+       more fields are added, but the intention is never to remove any of  the
        existing fields.


        The subscount field is the number of the current match. It is 1 for the
@@ -3518,25 +3521,25 @@
        first callout, 2 for the second, and so on. The input and output point-
        ers are copies of the values passed to pcre2_substitute().


-       The ovector field points to the ovector, which contains the  result  of
+       The  ovector  field points to the ovector, which contains the result of
        the most recent match. The oveccount field contains the number of pairs
        that are set in the ovector, and is always greater than zero.


-       The output_offsets vector contains the offsets of  the  replacement  in
-       the  output  string. This has already been processed for dollar and (if
+       The  output_offsets  vector  contains the offsets of the replacement in
+       the output string. This has already been processed for dollar  and  (if
        requested) backslash substitutions as described above.


-       The second argument of the callout function  is  the  value  passed  as
-       callout_data  when  the  function was registered. The value returned by
+       The  second  argument  of  the  callout function is the value passed as
+       callout_data when the function was registered. The  value  returned  by
        the callout function is interpreted as follows:


-       If the value is zero, the replacement is accepted, and,  if  PCRE2_SUB-
-       STITUTE_GLOBAL  is set, processing continues with a search for the next
-       match. If the value is not zero, the current  replacement  is  not  ac-
-       cepted.  If  the  value is greater than zero, processing continues when
-       PCRE2_SUBSTITUTE_GLOBAL is set. Otherwise (the value is less than  zero
-       or  PCRE2_SUBSTITUTE_GLOBAL  is  not set), the the rest of the input is
-       copied to the output and the call to pcre2_substitute() exits,  return-
+       If  the  value is zero, the replacement is accepted, and, if PCRE2_SUB-
+       STITUTE_GLOBAL is set, processing continues with a search for the  next
+       match.  If  the  value  is not zero, the current replacement is not ac-
+       cepted. If the value is greater than zero,  processing  continues  when
+       PCRE2_SUBSTITUTE_GLOBAL  is set. Otherwise (the value is less than zero
+       or PCRE2_SUBSTITUTE_GLOBAL is not set), the the rest of  the  input  is
+       copied  to the output and the call to pcre2_substitute() exits, return-
        ing the number of matches so far.



@@ -3545,56 +3548,56 @@
        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
-       capture groups are not required to be unique. Duplicate names  are  al-
-       ways  allowed for groups with the same number, created by using the (?|
+       When a pattern is compiled with the PCRE2_DUPNAMES  option,  names  for
+       capture  groups  are not required to be unique. Duplicate names are al-
+       ways allowed for groups with the same number, created by using the  (?|
        feature. Indeed, if such groups are named, they are required to use the
        same names.


-       Normally,  patterns  that  use duplicate names are such that in any one
-       match, only one of each set of identically-named  groups  participates.
+       Normally, patterns that use duplicate names are such that  in  any  one
+       match,  only  one of each set of identically-named groups 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_UN-
-       SET is returned. The  pcre2_substring_number_from_name()  function  re-
-       turns  the error PCRE2_ERROR_NOUNIQUESUBSTRING when there are duplicate
+       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_UN-
+       SET  is  returned.  The pcre2_substring_number_from_name() function re-
+       turns 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.



@@ -3606,26 +3609,26 @@
          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():
@@ -3645,45 +3648,45 @@


    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_COPY_MATCHED_SUBJECT, PCRE2_ENDANCHORED, PCRE2_NOTBOL,  PCRE2_NO-
+       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_COPY_MATCHED_SUBJECT,  PCRE2_ENDANCHORED, PCRE2_NOTBOL, PCRE2_NO-
        TEOL,   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
+       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 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.


@@ -3691,8 +3694,8 @@

        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


          <.*>
@@ -3707,80 +3710,80 @@
          <something> <something else>
          <something>


-       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  capture groups that may exist in the pattern, because DFA matching
+       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 capture groups that may exist in the pattern, because DFA  matching
        does not support capturing.


-       Calls to the convenience functions that extract substrings by name  re-
+       Calls  to the convenience functions that extract substrings by name re-
        turn the error PCRE2_ERROR_DFA_UFUNC (unsupported function) if used af-
-       ter a DFA match. The convenience functions that extract  substrings  by
+       ter  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 re-
+       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  re-
        ally do want multiple matches in such cases, either use an ungreedy re-
-       peat  such as "a\d+?" or set the PCRE2_NO_AUTO_POSSESS option when com-
+       peat such as "a\d+?" or set the PCRE2_NO_AUTO_POSSESS option when  com-
        piling.


    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 capture group. These are not supported.


          PCRE2_ERROR_DFA_UINVALID_UTF


-       This  return is given if pcre2_dfa_match() is called for a pattern that
-       was compiled with PCRE2_MATCH_INVALID_UTF. This is  not  supported  for
+       This return is given if pcre2_dfa_match() is called for a pattern  that
+       was  compiled  with  PCRE2_MATCH_INVALID_UTF. This is not supported for
        DFA matching.


          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 recursion or subroutine call 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  should  be  extremely  rare, as a vector of size 1000 is
+       calls itself recursively, using private  memory  for  the  ovector  and
+       workspace.   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).



@@ -3793,7 +3796,7 @@

REVISION

-       Last updated: 19 March 2020
+       Last updated: 05 October 2020
        Copyright (c) 1997-2020 University of Cambridge.
 ------------------------------------------------------------------------------


@@ -4831,10 +4834,10 @@

DIFFERENCES BETWEEN PCRE2 AND PERL

-       This document describes the differences in the ways that PCRE2 and Perl
-       handle regular expressions. The differences described here are with re-
-       spect to Perl versions 5.26, but as both Perl and PCRE2 are continually
-       changing, the information may sometimes be out of date.
+       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 information may at times be out of date.


        1. PCRE2 has only a subset of Perl's Unicode support. Details  of  what
        it does have are given in the pcre2unicode page.
@@ -4845,40 +4848,43 @@
        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}), but these do not seem to have any use.
+       \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.


        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).
+       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,
+       4.  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
        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&.  PCRE2 does support the Cs (surrogate) property,
-       which  Perl  does  not; the Perl documentation says "Because Perl hides
-       the need for the user to understand the internal representation of Uni-
-       code  characters, there is no need to implement the somewhat messy con-
-       cept of surrogates."
+       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
        in between are treated as literals. However, this is slightly different
-       from Perl in that $ and @ are  also  handled  as  literals  inside  the
+       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
+       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:


@@ -4891,78 +4897,79 @@
            \QA\B\E            A\B               A\B
            \Q\\E              \                 \\E


-       The \Q...\E sequence is recognized both inside  and  outside  character
-       classes.
+       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
+       7.  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 to PCRE2 release 10.23, but from release 10.30 this changed,
+       8.  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. 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 that is called as a subroutine, its action  is  lim-
-       ited  to  that  group, even if the group does not contain any | charac-
-       ters. Note that such groups are processed  as  anchored  at  the  point
-       where they are tested.
+       9.  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,
+       if  (*THEN)  is  present in a group 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.


-       10.  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
+       10. 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.  Most  backtracking  verbs in assertions have their normal actions.
-       They are not confined to the assertion.
-
-       12. There are some differences that are concerned with the settings  of
+       11. 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".


-       13.  PCRE2's  handling  of duplicate capture group numbers and names is
+       12.  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
-       (?|(?<a>A)|(?<b>B),  where  the two capture groups have the same number
+       (?|(?<a>A)|(?<b>B)),  where the two capture groups have the same number
        but different names, is not supported, and 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.


-       14. Perl used to recognize comments in some places that PCRE2 does not,
+       13. 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.


-       15.  Perl,  when  in warning mode, gives warnings for character classes
+       14.  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.


-       16. In PCRE2, the upper/lower case character properties Lu and  Ll  are
+       15. 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 (5.24), \p{Lu} and
+       this  respect; in the release at the time of writing (5.32), \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-
+       sertions. In PCRE2, \K is acted on when it occurs  in  positive  asser-
+       tions, but is ignored in negative assertions.
+
        17.  PCRE2  provides some extensions to the Perl regular expression fa-
-       cilities.  Perl 5.10 includes new features that are not in earlier ver-
-       sions  of Perl, some of which (such as named parentheses) were in PCRE2
-       for some time before. This list is with respect to Perl 5.26:
+       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:


        (a) Although lookbehind assertions in PCRE2  must  match  fixed  length
-       strings,  each alternative branch of a lookbehind assertion can match a
-       different length of string. Perl requires them all  to  have  the  same
-       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.


        (b) From PCRE2 10.23, backreferences to groups of fixed length are sup-
        ported in lookbehinds, provided that there is no possibility of  refer-
@@ -4997,7 +5004,7 @@
        different way and is not Perl-compatible.


        (l)  PCRE2 recognizes some special sequences such as (*CR) or (*NO_JIT)
-       at the start of a pattern that  set  overall  options  that  cannot  be
+       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
@@ -5026,7 +5033,7 @@


REVISION

-       Last updated: 13 July 2019
+       Last updated: 06 October 2020
        Copyright (c) 1997-2019 University of Cambridge.
 ------------------------------------------------------------------------------


@@ -6353,8 +6360,12 @@
          The quick brown fox


        matches a portion of a subject string that is identical to itself. When
-       caseless matching is specified (the PCRE2_CASELESS option), letters are
-       matched independently of case.
+       caseless  matching  is  specified  (the  PCRE2_CASELESS  option or (?i)
+       within the pattern), letters are matched independently  of  case.  Note
+       that  there  are  two  ASCII  characters, K and S, that, in addition to
+       their lower case ASCII equivalents, are  case-equivalent  with  Unicode
+       U+212A  (Kelvin  sign)  and  U+017F  (long  S) respectively when either
+       PCRE2_UTF or PCRE2_UCP is set.


        The power of regular expressions comes from the ability to include wild
        cards, character classes, alternatives, and repetitions in the pattern.
@@ -6389,6 +6400,18 @@
          [      POSIX character class (if followed by POSIX syntax)
          ]      terminates the character class


+       If a pattern is compiled with the  PCRE2_EXTENDED  option,  most  white
+       space  in  the pattern, other than in a character class, and characters
+       between a # outside a character class and the next newline,  inclusive,
+       are ignored. An escaping backslash can be used to include a white space
+       or a # character as part of the pattern. If the PCRE2_EXTENDED_MORE op-
+       tion is set, the same applies, but in addition unescaped space and hor-
+       izontal 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.  Option
+       settings can be changed within a pattern; see the section entitled "In-
+       ternal Option Setting" below.
+
        The following sections describe the use of each of the metacharacters.



@@ -6406,16 +6429,10 @@
        that it stands for itself.  In particular, if you want to match a back-
        slash, you write \\.


-       In a UTF mode, only ASCII digits and letters have any  special  meaning
-       after  a  backslash.  All  other characters (in particular, those whose
-       code points are greater than 127) are treated as literals.
+       Only ASCII digits and letters have any special meaning  after  a  back-
+       slash. All other characters (in particular, those whose code points are
+       greater than 127) are treated as literals.


-       If a pattern is compiled with the  PCRE2_EXTENDED  option,  most  white
-       space  in the pattern (other than in a character class), and characters
-       between a # outside a character class and the next newline,  inclusive,
-       are ignored. An escaping backslash can be used to include a white space
-       or # character as part of the pattern.
-
        If you want to treat all characters in a sequence as literals, you  can
        do so by putting them between \Q and \E. This is different from Perl in
        that $ and @ are handled as literals in  \Q...\E  sequences  in  PCRE2,
@@ -7039,27 +7056,28 @@


        matches "foobar", the first substring is still set to "foo".


-       Perl  documents  that  the use of \K within assertions is "not well de-
-       fined". In PCRE2, \K is acted upon when it occurs inside  positive  as-
-       sertions,  but is ignored in negative assertions. Note that when a pat-
-       tern such as (?=ab\K) matches, the reported start of the match  can  be
-       greater  than  the end of the match. Using \K in a lookbehind assertion
-       at the start of a pattern can also lead to odd  effects.  For  example,
-       consider this pattern:
+       Perl  used  to document that the use of \K within lookaround assertions
+       is "not well defined", but from version 5.32.0 Perl  does  not  support
+       this  usage  at  all.  In PCRE2, \K is acted upon when it occurs inside
+       positive assertions, but is ignored in negative assertions.  Note  that
+       when  a  pattern  such  as  (?=ab\K) matches, the reported start of the
+       match can be greater than the end of the match. Using \K in  a  lookbe-
+       hind  assertion at the start of a pattern can also lead to odd effects.
+       For example, consider this pattern:


          (?<=\Kfoo)bar


-       If  the  subject  is  "foobar", a call to pcre2_match() with a starting
-       offset of 3 succeeds and reports the matching string as "foobar",  that
-       is,  the  start  of  the reported match is earlier than where the match
+       If the subject is "foobar", a call to  pcre2_match()  with  a  starting
+       offset  of 3 succeeds and reports the matching string as "foobar", that
+       is, the start of the reported match is earlier  than  where  the  match
        started.


    Simple assertions


-       The final use of backslash is for certain simple assertions. An  asser-
-       tion  specifies a condition that has to be met at a particular point in
-       a match, without consuming any characters from the subject string.  The
-       use  of groups for more complicated assertions is described below.  The
+       The  final use of backslash is for certain simple assertions. An asser-
+       tion specifies a condition that has to be met at a particular point  in
+       a  match, without consuming any characters from the subject string. The
+       use of groups for more complicated assertions is described below.   The
        backslashed assertions are:


          \b     matches at a word boundary
@@ -7070,48 +7088,48 @@
          \z     matches only at the end of the subject
          \G     matches at the first matching position in the subject


-       Inside a character class, \b has a different meaning;  it  matches  the
-       backspace  character.  If  any  other  of these assertions appears in a
+       Inside  a  character  class, \b has a different meaning; it matches the
+       backspace character. If any other of  these  assertions  appears  in  a
        character class, an "invalid escape sequence" error is generated.


-       A word boundary is a position in the subject string where  the  current
-       character  and  the previous character do not both match \w or \W (i.e.
-       one matches \w and the other matches \W), or the start or  end  of  the
-       string  if  the  first or last character matches \w, respectively. When
-       PCRE2 is built with Unicode support, the meanings of \w and \W  can  be
+       A  word  boundary is a position in the subject string where the current
+       character and the previous character do not both match \w or  \W  (i.e.
+       one  matches  \w  and the other matches \W), or the start or end of the
+       string if the first or last character matches  \w,  respectively.  When
+       PCRE2  is  built with Unicode support, the meanings of \w and \W can be
        changed by setting the PCRE2_UCP option. When this is done, it also af-
-       fects \b and \B. Neither PCRE2 nor Perl has a separate "start of  word"
-       or  "end  of  word" metasequence. However, whatever follows \b normally
-       determines which it is. For example, the fragment \ba  matches  "a"  at
+       fects  \b and \B. Neither PCRE2 nor Perl has a separate "start of word"
+       or "end of word" metasequence. However, whatever  follows  \b  normally
+       determines  which  it  is. For example, the fragment \ba matches "a" at
        the start of a word.


-       The  \A,  \Z,  and \z assertions differ from the traditional circumflex
+       The \A, \Z, and \z assertions differ from  the  traditional  circumflex
        and dollar (described in the next section) in that they only ever match
-       at  the  very start and end of the subject string, whatever options are
-       set. Thus, they are independent of multiline mode. These  three  asser-
-       tions  are  not  affected  by the PCRE2_NOTBOL or PCRE2_NOTEOL options,
-       which affect only the behaviour of the circumflex and dollar  metachar-
-       acters.  However,  if the startoffset argument of pcre2_match() is non-
-       zero, indicating that matching is to start at a point  other  than  the
-       beginning  of  the subject, \A can never match.  The difference between
-       \Z and \z is that \Z matches before a newline at the end of the  string
+       at the very start and end of the subject string, whatever  options  are
+       set.  Thus,  they are independent of multiline mode. These three asser-
+       tions are not affected by the  PCRE2_NOTBOL  or  PCRE2_NOTEOL  options,
+       which  affect only the behaviour of the circumflex and dollar metachar-
+       acters. However, if the startoffset argument of pcre2_match()  is  non-
+       zero,  indicating  that  matching is to start at a point other than the
+       beginning of the subject, \A can never match.  The  difference  between
+       \Z  and \z is that \Z matches before a newline at the end of the string
        as well as at the very end, whereas \z matches only at the end.


-       The  \G assertion is true only when the current matching position is at
-       the start point of the matching process, as specified by the  startoff-
-       set  argument  of  pcre2_match().  It differs from \A when the value of
-       startoffset is non-zero. By calling pcre2_match() multiple  times  with
-       appropriate  arguments,  you  can  mimic Perl's /g option, and it is in
+       The \G assertion is true only when the current matching position is  at
+       the  start point of the matching process, as specified by the startoff-
+       set argument of pcre2_match(). It differs from \A  when  the  value  of
+       startoffset  is  non-zero. By calling pcre2_match() multiple times with
+       appropriate arguments, you can mimic Perl's /g option,  and  it  is  in
        this kind of implementation where \G can be useful.


-       Note, however, that PCRE2's implementation of \G,  being  true  at  the
-       starting  character  of  the matching process, is subtly different from
-       Perl's, which defines it as true at the end of the previous  match.  In
-       Perl,  these  can  be  different when the previously matched string was
+       Note,  however,  that  PCRE2's  implementation of \G, being true at the
+       starting character of the matching process, is  subtly  different  from
+       Perl's,  which  defines it as true at the end of the previous match. In
+       Perl, these can be different when the  previously  matched  string  was
        empty. Because PCRE2 does just one match at a time, it cannot reproduce
        this behaviour.


-       If  all  the alternatives of a pattern begin with \G, the expression is
+       If all the alternatives of a pattern begin with \G, the  expression  is
        anchored to the starting match position, and the "anchored" flag is set
        in the compiled regular expression.


@@ -7118,70 +7136,70 @@

CIRCUMFLEX AND DOLLAR

-       The  circumflex  and  dollar  metacharacters are zero-width assertions.
-       That is, they test for a particular condition being true  without  con-
+       The circumflex and dollar  metacharacters  are  zero-width  assertions.
+       That  is,  they test for a particular condition being true without con-
        suming any characters from the subject string. These two metacharacters
-       are concerned with matching the starts and ends of lines. If  the  new-
-       line  convention is set so that only the two-character sequence CRLF is
-       recognized as a newline, isolated CR and LF characters are  treated  as
+       are  concerned  with matching the starts and ends of lines. If the new-
+       line convention is set so that only the two-character sequence CRLF  is
+       recognized  as  a newline, isolated CR and LF characters are treated as
        ordinary data characters, and are not recognized as newlines.


        Outside a character class, in the default matching mode, the circumflex
-       character is an assertion that is true only  if  the  current  matching
-       point  is  at the start of the subject string. If the startoffset argu-
-       ment of pcre2_match() is non-zero, or if PCRE2_NOTBOL is  set,  circum-
-       flex  can  never match if the PCRE2_MULTILINE option is unset. Inside a
-       character class, circumflex has an entirely different meaning (see  be-
+       character  is  an  assertion  that is true only if the current matching
+       point is at the start of the subject string. If the  startoffset  argu-
+       ment  of  pcre2_match() is non-zero, or if PCRE2_NOTBOL is set, circum-
+       flex can never match if the PCRE2_MULTILINE option is unset.  Inside  a
+       character  class, circumflex has an entirely different meaning (see be-
        low).


-       Circumflex  need  not be the first character of the pattern if a number
-       of alternatives are involved, but it should be the first thing in  each
-       alternative  in  which  it appears if the pattern is ever to match that
-       branch. If all possible alternatives start with a circumflex, that  is,
-       if  the  pattern  is constrained to match only at the start of the sub-
-       ject, it is said to be an "anchored" pattern.  (There  are  also  other
+       Circumflex need not be the first character of the pattern if  a  number
+       of  alternatives are involved, but it should be the first thing in each
+       alternative in which it appears if the pattern is ever  to  match  that
+       branch.  If all possible alternatives start with a circumflex, that is,
+       if the pattern is constrained to match only at the start  of  the  sub-
+       ject,  it  is  said  to be an "anchored" pattern. (There are also other
        constructs that can cause a pattern to be anchored.)


-       The  dollar  character is an assertion that is true only if the current
-       matching point is at the end of the subject string, or immediately  be-
-       fore  a newline at the end of the string (by default), unless PCRE2_NO-
-       TEOL is set. Note, however, that it does not actually  match  the  new-
-       line.  Dollar need not be the last character of the pattern if a number
-       of alternatives are involved, but it should be the  last  item  in  any
-       branch  in which it appears. Dollar has no special meaning in a charac-
+       The dollar character is an assertion that is true only if  the  current
+       matching  point is at the end of the subject string, or immediately be-
+       fore a newline at the end of the string (by default), unless  PCRE2_NO-
+       TEOL  is  set.  Note, however, that it does not actually match the new-
+       line. Dollar need not be the last character of the pattern if a  number
+       of  alternatives  are  involved,  but it should be the last item in any
+       branch in which it appears. Dollar has no special meaning in a  charac-
        ter class.


-       The meaning of dollar can be changed so that it  matches  only  at  the
-       very  end  of the string, by setting the PCRE2_DOLLAR_ENDONLY option at
+       The  meaning  of  dollar  can be changed so that it matches only at the
+       very end of the string, by setting the PCRE2_DOLLAR_ENDONLY  option  at
        compile time. This does not affect the \Z assertion.


        The meanings of the circumflex and dollar metacharacters are changed if
-       the  PCRE2_MULTILINE  option  is  set.  When this is the case, a dollar
-       character matches before any newlines in the string, as well as at  the
-       very  end, and a circumflex matches immediately after internal newlines
-       as well as at the start of the subject string. It does not match  after
-       a  newline  that ends the string, for compatibility with Perl. However,
+       the PCRE2_MULTILINE option is set. When this  is  the  case,  a  dollar
+       character  matches before any newlines in the string, as well as at the
+       very end, and a circumflex matches immediately after internal  newlines
+       as  well as at the start of the subject string. It does not match after
+       a newline that ends the string, for compatibility with  Perl.  However,
        this can be changed by setting the PCRE2_ALT_CIRCUMFLEX option.


-       For example, the pattern /^abc$/ matches the subject string  "def\nabc"
-       (where  \n  represents a newline) in multiline mode, but not otherwise.
-       Consequently, patterns that are anchored in single  line  mode  because
-       all  branches  start  with  ^ are not anchored in multiline mode, and a
-       match for circumflex is  possible  when  the  startoffset  argument  of
-       pcre2_match()  is  non-zero. The PCRE2_DOLLAR_ENDONLY option is ignored
+       For  example, the pattern /^abc$/ matches the subject string "def\nabc"
+       (where \n represents a newline) in multiline mode, but  not  otherwise.
+       Consequently,  patterns  that  are anchored in single line mode because
+       all branches start with ^ are not anchored in  multiline  mode,  and  a
+       match  for  circumflex  is  possible  when  the startoffset argument of
+       pcre2_match() is non-zero. The PCRE2_DOLLAR_ENDONLY option  is  ignored
        if PCRE2_MULTILINE is set.


-       When the newline convention (see "Newline  conventions"  below)  recog-
-       nizes  the two-character sequence CRLF as a newline, this is preferred,
-       even if the single characters CR and LF are  also  recognized  as  new-
-       lines.  For  example,  if  the newline convention is "any", a multiline
-       mode circumflex matches before "xyz" in the string "abc\r\nxyz"  rather
-       than  after  CR, even though CR on its own is a valid newline. (It also
+       When  the  newline  convention (see "Newline conventions" below) recog-
+       nizes the two-character sequence CRLF as a newline, this is  preferred,
+       even  if  the  single  characters CR and LF are also recognized as new-
+       lines. For example, if the newline convention  is  "any",  a  multiline
+       mode  circumflex matches before "xyz" in the string "abc\r\nxyz" rather
+       than after CR, even though CR on its own is a valid newline.  (It  also
        matches at the very start of the string, of course.)


-       Note that the sequences \A, \Z, and \z can be used to match  the  start
-       and  end of the subject in both modes, and if all branches of a pattern
-       start with \A it is always anchored, whether or not PCRE2_MULTILINE  is
+       Note  that  the sequences \A, \Z, and \z can be used to match the start
+       and end of the subject in both modes, and if all branches of a  pattern
+       start  with \A it is always anchored, whether or not PCRE2_MULTILINE is
        set.



@@ -7188,73 +7206,73 @@
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-
+       ter  in  the subject string except (by default) a character that signi-
        fies the end of a line.


-       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
+       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.


-       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.  If the two-character sequence CRLF is present in  the  sub-
+       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.   If  the two-character sequence CRLF is present in the sub-
        ject string, it takes two dots to match it.


-       The  handling of dot is entirely independent of the handling of circum-
-       flex and dollar, the only relationship being  that  they  both  involve
+       The handling of dot is entirely independent of the handling of  circum-
+       flex  and  dollar,  the  only relationship being that they both involve
        newlines. Dot has no special meaning in a character class.


-       The  escape  sequence  \N when not followed by an opening brace behaves
-       like a dot, except that it is not affected by the PCRE2_DOTALL  option.
-       In  other words, it matches any character except one that signifies the
+       The escape sequence \N when not followed by an  opening  brace  behaves
+       like  a dot, except that it is not affected by the PCRE2_DOTALL option.
+       In other words, it matches any character except one that signifies  the
        end of a line.


        When \N is followed by an opening brace it has a different meaning. See
-       the  section entitled "Non-printing characters" above for details. Perl
-       also uses \N{name} to specify characters by Unicode  name;  PCRE2  does
+       the section entitled "Non-printing characters" above for details.  Perl
+       also  uses  \N{name}  to specify characters by Unicode name; PCRE2 does
        not support this.



MATCHING A SINGLE CODE UNIT

-       Outside  a character class, the escape sequence \C matches any one code
-       unit, whether or not a UTF mode is set. In the 8-bit library, one  code
-       unit  is  one  byte;  in the 16-bit library it is a 16-bit unit; in the
-       32-bit library it is a 32-bit unit. Unlike a  dot,  \C  always  matches
-       line-ending  characters.  The  feature  is provided in Perl in order to
+       Outside a character class, the escape sequence \C matches any one  code
+       unit,  whether or not a UTF mode is set. In the 8-bit library, one code
+       unit is one byte; in the 16-bit library it is a  16-bit  unit;  in  the
+       32-bit  library  it  is  a 32-bit unit. Unlike a dot, \C always matches
+       line-ending characters. The feature is provided in  Perl  in  order  to
        match individual bytes in UTF-8 mode, but it is unclear how it can use-
        fully be used.


-       Because  \C  breaks  up characters into individual code units, matching
-       one unit with \C in UTF-8 or UTF-16 mode means that  the  rest  of  the
+       Because \C breaks up characters into individual  code  units,  matching
+       one  unit  with  \C  in UTF-8 or UTF-16 mode means that the rest of the
        string may start with a malformed UTF character. This has undefined re-
        sults, because PCRE2 assumes that it is matching character by character
        in a valid UTF string (by default it checks the subject string's valid-
-       ity at  the  start  of  processing  unless  the  PCRE2_NO_UTF_CHECK  or
+       ity  at  the  start  of  processing  unless  the  PCRE2_NO_UTF_CHECK or
        PCRE2_MATCH_INVALID_UTF option is used).


-       An   application   can   lock   out  the  use  of  \C  by  setting  the
-       PCRE2_NEVER_BACKSLASH_C option when compiling a  pattern.  It  is  also
+       An  application  can  lock  out  the  use  of   \C   by   setting   the
+       PCRE2_NEVER_BACKSLASH_C  option  when  compiling  a pattern. It is also
        possible to build PCRE2 with the use of \C permanently disabled.


-       PCRE2  does  not allow \C to appear in lookbehind assertions (described
-       below) in UTF-8 or UTF-16 modes, because this would make it  impossible
-       to  calculate  the  length  of  the lookbehind. Neither the alternative
+       PCRE2 does not allow \C to appear in lookbehind  assertions  (described
+       below)  in UTF-8 or UTF-16 modes, because this would make it impossible
+       to calculate the length of  the  lookbehind.  Neither  the  alternative
        matching function pcre2_dfa_match() nor the JIT optimizer support \C in
        these UTF modes.  The former gives a match-time error; the latter fails
        to optimize and so the match is always run using the interpreter.


-       In the 32-bit library, however, \C is always supported  (when  not  ex-
-       plicitly  locked  out)  because  it  always matches a single code unit,
+       In  the  32-bit  library, however, \C is always supported (when not ex-
+       plicitly locked out) because it always  matches  a  single  code  unit,
        whether or not UTF-32 is specified.


        In general, the \C escape sequence is best avoided. However, one way of
-       using  it  that avoids the problem of malformed UTF-8 or UTF-16 charac-
-       ters is to use a lookahead to check the length of the  next  character,
-       as  in  this  pattern,  which could be used with a UTF-8 string (ignore
+       using it that avoids the problem of malformed UTF-8 or  UTF-16  charac-
+       ters  is  to use a lookahead to check the length of the next character,
+       as in this pattern, which could be used with  a  UTF-8  string  (ignore
        white space and line breaks):


          (?| (?=[\x00-\x7f])(\C) |
@@ -7262,11 +7280,11 @@
              (?=[\x{800}-\x{ffff}])(\C)(\C)(\C) |
              (?=[\x{10000}-\x{1fffff}])(\C)(\C)(\C)(\C))


-       In this example, a group that starts  with  (?|  resets  the  capturing
-       parentheses  numbers in each alternative (see "Duplicate Group Numbers"
+       In  this  example,  a  group  that starts with (?| resets the capturing
+       parentheses numbers in each alternative (see "Duplicate Group  Numbers"
        below). The assertions at the start of each branch check the next UTF-8
-       character  for  values whose encoding uses 1, 2, 3, or 4 bytes, respec-
-       tively. The character's individual bytes are then captured by  the  ap-
+       character for values whose encoding uses 1, 2, 3, or 4  bytes,  respec-
+       tively.  The  character's individual bytes are then captured by the ap-
        propriate number of \C groups.



@@ -7274,34 +7292,37 @@

        An opening square bracket introduces a character class, terminated by a
        closing square bracket. A closing square bracket on its own is not spe-
-       cial  by  default.  If a closing square bracket is required as a member
+       cial by default.  If a closing square bracket is required as  a  member
        of the class, it should be the first data character in the class (after
-       an  initial  circumflex,  if present) or escaped with a backslash. This
-       means that, by default, an empty class cannot be defined.  However,  if
-       the  PCRE2_ALLOW_EMPTY_CLASS option is set, a closing square bracket at
+       an initial circumflex, if present) or escaped with  a  backslash.  This
+       means  that,  by default, an empty class cannot be defined. However, if
+       the PCRE2_ALLOW_EMPTY_CLASS option is set, a closing square bracket  at
        the start does end the (empty) class.


-       A character class matches a single character in the subject. A  matched
+       A  character class matches a single character in the subject. A matched
        character must be in the set of characters defined by the class, unless
-       the first character in the class definition is a circumflex,  in  which
+       the  first  character in the class definition is a circumflex, in which
        case the subject character must not be in the set defined by the class.
-       If a circumflex is actually required as a member of the  class,  ensure
+       If  a  circumflex is actually required as a member of the class, ensure
        it is not the first character, or escape it with a backslash.


-       For  example, the character class [aeiou] matches any lower case vowel,
-       while [^aeiou] matches any character that is not a  lower  case  vowel.
+       For example, the character class [aeiou] matches any lower case  vowel,
+       while  [^aeiou]  matches  any character that is not a lower case vowel.
        Note that a circumflex is just a convenient notation for specifying the
-       characters that are in the class by enumerating those that are  not.  A
-       class  that starts with a circumflex is not an assertion; it still con-
-       sumes a character from the subject string, and therefore  it  fails  if
+       characters  that  are in the class by enumerating those that are not. A
+       class that starts with a circumflex is not an assertion; it still  con-
+       sumes  a  character  from the subject string, and therefore it fails if
        the current pointer is at the end of the string.


-       Characters  in  a class may be specified by their code points using \o,
-       \x, or \N{U+hh..} in the usual way. When caseless matching is set,  any
-       letters  in a class represent both their upper case and lower case ver-
-       sions, so for example, a caseless [aeiou] matches "A" as well  as  "a",
-       and  a  caseless [^aeiou] does not match "A", whereas a caseful version
-       would.
+       Characters in a class may be specified by their code points  using  \o,
+       \x,  or \N{U+hh..} in the usual way. When caseless matching is set, any
+       letters in a class represent both their upper case and lower case  ver-
+       sions,  so  for example, a caseless [aeiou] matches "A" as well as "a",
+       and a caseless [^aeiou] does not match "A", whereas a  caseful  version
+       would.  Note that there are two ASCII characters, K and S, that, in ad-
+       dition to their lower case ASCII equivalents, are case-equivalent  with
+       Unicode  U+212A (Kelvin sign) and U+017F (long S) respectively when ei-
+       ther PCRE2_UTF or PCRE2_UCP is set.


        Characters that might indicate line breaks are  never  treated  in  any
        special  way  when matching character classes, whatever line-ending se-
@@ -9559,7 +9580,7 @@


REVISION

-       Last updated: 24 February 2020
+       Last updated: 06 October 2020
        Copyright (c) 1997-2020 University of Cambridge.
 ------------------------------------------------------------------------------



Modified: code/trunk/doc/pcre2compat.3
===================================================================
--- code/trunk/doc/pcre2compat.3    2020-10-06 08:04:40 UTC (rev 1276)
+++ code/trunk/doc/pcre2compat.3    2020-10-07 16:27:20 UTC (rev 1277)
@@ -1,13 +1,13 @@
-.TH PCRE2COMPAT 3 "13 July 2019" "PCRE2 10.34"
+.TH PCRE2COMPAT 3 "06 October 2020" "PCRE2 10.36"
 .SH NAME
 PCRE2 - Perl-compatible regular expressions (revised API)
 .SH "DIFFERENCES BETWEEN PCRE2 AND PERL"
 .rs
 .sp
-This document describes the differences in the ways that PCRE2 and Perl handle
-regular expressions. The differences described here are with respect to Perl
-versions 5.26, but as both Perl and PCRE2 are continually changing, the
-information may sometimes be out of date.
+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
+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
 have are given in the
@@ -21,11 +21,14 @@
 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}), but these do not seem to have any use.
+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.
 .P
 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).
+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,
 \eU, and \eN when followed by a character name. \eN on its own, matching a
@@ -41,10 +44,14 @@
 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&.
-PCRE2 does support the Cs (surrogate) property, which Perl does not; the Perl
-documentation says "Because Perl hides the need for the user to understand the
-internal representation of Unicode characters, there is no need to implement
-the somewhat messy concept of surrogates."
+Both PCRE2 and Perl support the Cs (surrogate) property, but in PCRE2 its use
+is limited. See the
+.\" HREF
+\fBpcre2pattern\fP
+.\"
+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
 in between are treated as literals. However, this is slightly different from
@@ -65,7 +72,8 @@
     \eQA\eB\eE            A\eB               A\eB
     \eQ\e\eE              \e                 \e\eE
 .sp
-The \eQ...\eE sequence is recognized both inside and outside character classes.
+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})
 constructions. However, PCRE2 does have a "callout" feature, which allows an
@@ -79,13 +87,13 @@
 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. 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 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.
+9. 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
+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
 one that is backtracked onto acts. For example, in the pattern
@@ -93,48 +101,49 @@
 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. Most backtracking verbs in assertions have their normal actions. They are
-not confined to the assertion.
-.P
-12. There are some differences that are concerned with the settings of captured
+11. 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
-13. PCRE2's handling of duplicate capture group numbers and names is not as
+12. 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
+names. In particular, a pattern such as (?|(?<a>A)|(?<b>B)), where the two
 capture groups have the same number but different names, is not supported, and
 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
-14. Perl used to recognize comments in some places that PCRE2 does not, for
+13. 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
-15. Perl, when in warning mode, gives warnings for character classes such as
+14. 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
-16. In PCRE2, the upper/lower case character properties Lu and Ll are not
+15. 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 (5.24), \ep{Lu} and \ep{Ll} match all
+in the release at the time of writing (5.32), \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 
+assertions. In PCRE2, \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.
-Perl 5.10 includes new features that are not in earlier versions of Perl, some
+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 5.26:
+list is with respect to Perl 5.32:
 .sp
 (a) Although lookbehind assertions in PCRE2 must match fixed length strings,
-each alternative branch of a lookbehind assertion can match a different length
-of string. Perl requires them all to have the same length.
+each alternative toplevel branch of a lookbehind assertion can match a
+different length of string. Perl requires them all to have the same length.
 .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
@@ -168,7 +177,7 @@
 different way and is not Perl-compatible.
 .sp
 (l) PCRE2 recognizes some special sequences such as (*CR) or (*NO_JIT) at
-the start of a pattern that set overall options that cannot be changed within
+the start of a pattern. These set overall options that cannot be changed within
 the pattern.
 .sp
 (m) PCRE2 supports non-atomic positive lookaround assertions. This is an
@@ -203,6 +212,6 @@
 .rs
 .sp
 .nf
-Last updated: 13 July 2019
+Last updated: 06 October 2020
 Copyright (c) 1997-2019 University of Cambridge.
 .fi


Modified: code/trunk/doc/pcre2pattern.3
===================================================================
--- code/trunk/doc/pcre2pattern.3    2020-10-06 08:04:40 UTC (rev 1276)
+++ code/trunk/doc/pcre2pattern.3    2020-10-07 16:27:20 UTC (rev 1277)
@@ -1,4 +1,4 @@
-.TH PCRE2PATTERN 3 "05 October 2020" "PCRE2 10.35"
+.TH PCRE2PATTERN 3 "06 October 2020" "PCRE2 10.35"
 .SH NAME
 PCRE2 - Perl-compatible regular expressions (revised API)
 .SH "PCRE2 REGULAR EXPRESSION DETAILS"
@@ -1168,8 +1168,9 @@
 .sp
 matches "foobar", the first substring is still set to "foo".
 .P
-Perl documents that the use of \eK within assertions is "not well defined". In
-PCRE2, \eK is acted upon when it occurs inside positive assertions, but is
+Perl used to document that the use of \eK within lookaround assertions is "not
+well defined", but from version 5.32.0 Perl does not support this usage at all.
+In PCRE2, \eK is acted upon when it occurs inside positive assertions, but is
 ignored in negative assertions. Note that when a pattern such as (?=ab\eK)
 matches, the reported start of the match can be greater than the end of the
 match. Using \eK in a lookbehind assertion at the start of a pattern can also
@@ -3897,6 +3898,6 @@
 .rs
 .sp
 .nf
-Last updated: 05 October 2020
+Last updated: 06 October 2020
 Copyright (c) 1997-2020 University of Cambridge.
 .fi