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Documentation update.

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ph10 2017-04-17 15:39:09 +00:00
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34
doc/html/pcre2compat.html
View File

@ -18,7 +18,7 @@ DIFFERENCES BETWEEN PCRE2 AND PERL
<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 5.24, but as both Perl and PCRE2 are continually changing, the
versions 5.26, but as both Perl and PCRE2 are continually changing, the
information may sometimes be out of date.
</P>
<P>
@ -148,7 +148,7 @@ letters, regardless of case, when case independence is specified.
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
of which (such as named parentheses) were in PCRE2 for some time before. This
list is with respect to Perl 5.24:
list is with respect to Perl 5.26:
<br>
<br>
(a) Although lookbehind assertions in PCRE2 must match fixed length strings,
@ -178,15 +178,16 @@ question mark they are.
only at the first matching position in the subject string.
<br>
<br>
(g) The PCRE2_NOTBOL, PCRE2_NOTEOL, PCRE2_NOTEMPTY, PCRE2_NOTEMPTY_ATSTART, and
PCRE2_NO_AUTO_CAPTURE options have no Perl equivalents.
(g) The PCRE2_NOTBOL, PCRE2_NOTEOL, PCRE2_NOTEMPTY and PCRE2_NOTEMPTY_ATSTART
options have no Perl equivalents.
<br>
<br>
(h) The \R escape sequence can be restricted to match only CR, LF, or CRLF
by the PCRE2_BSR_ANYCRLF option.
<br>
<br>
(i) The callout facility is PCRE2-specific.
(i) The callout facility is PCRE2-specific. Perl supports codeblocks and
variable interpolation, but not general hooks on every match.
<br>
<br>
(j) The partial matching facility is PCRE2-specific.
@ -196,8 +197,25 @@ by the PCRE2_BSR_ANYCRLF option.
different way and is not Perl-compatible.
<br>
<br>
(l) PCRE2 recognizes some special sequences such as (*CR) at the start of
a pattern that set overall options that cannot be changed within the pattern.
(l) PCRE2 recognizes some special sequences such as (*CR) or (*NO_JIT) at
the start of a pattern that set overall options that cannot be changed within
the pattern.
<br>
<br>
18. The following new Perl 5.26 constructs are not yet supported in PCRE2:
<br>
<br>
(a) The Perl /a modifier restricts /d numbers to pure ascii, the new /aa
modifier restricts /i case-insensitive matching to pure ascii also, ignoring
unicode rules. This separation cannot be represented with PCRE2_UTF.
<br>
<br>
19. Perl has different limits than PCRE2. See the
<a href="pcre2limit.html"><b>pcre2limit</b></a>
documentation for details. Perl went with 5.10 from recursion to iteration
keeping the intermediate matches on the heap, which is ~10% slower but does not
fall into any stack-overflow limit. PCRE2 made a similar change at release
10.30, and also has many build-time and run-time customizable limits.
</P>
<br><b>
AUTHOR
@ -214,7 +232,7 @@ Cambridge, England.
REVISION
</b><br>
<P>
Last updated: 03 April 2017
Last updated: 17 April 2017
<br>
Copyright &copy; 1997-2017 University of Cambridge.
<br>

37
doc/pcre2.txt
View File

@ -4203,7 +4203,7 @@ 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
respect to Perl versions 5.24, but as both Perl and PCRE2 are continu-
respect to Perl versions 5.26, but as both Perl and PCRE2 are continu-
ally changing, the information may sometimes be out of date.
1. PCRE2 has only a subset of Perl's Unicode support. Details of what
@ -4320,7 +4320,7 @@ DIFFERENCES BETWEEN PCRE2 AND PERL
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 of which (such as named parentheses) were in
PCRE2 for some time before. This list is with respect to Perl 5.24:
PCRE2 for some time before. This list is with respect to Perl 5.26:
(a) Although lookbehind assertions in PCRE2 must match fixed length
strings, each alternative branch of a lookbehind assertion can match a
@ -4345,23 +4345,38 @@ DIFFERENCES BETWEEN PCRE2 AND PERL
(f) PCRE2_ANCHORED can be used at matching time to force a pattern to
be tried only at the first matching position in the subject string.
(g) The PCRE2_NOTBOL, PCRE2_NOTEOL, PCRE2_NOTEMPTY,
PCRE2_NOTEMPTY_ATSTART, and PCRE2_NO_AUTO_CAPTURE options have no Perl
equivalents.
(g) The PCRE2_NOTBOL, PCRE2_NOTEOL, PCRE2_NOTEMPTY and
PCRE2_NOTEMPTY_ATSTART options have no Perl equivalents.
(h) The \R escape sequence can be restricted to match only CR, LF, or
(h) The \R escape sequence can be restricted to match only CR, LF, or
CRLF by the PCRE2_BSR_ANYCRLF option.
(i) The callout facility is PCRE2-specific.
(i) The callout facility is PCRE2-specific. Perl supports codeblocks
and variable interpolation, but not general hooks on every match.
(j) The partial matching facility is PCRE2-specific.
(k) The alternative matching function (pcre2_dfa_match() matches in a
different way and is not Perl-compatible.
(l) PCRE2 recognizes some special sequences such as (*CR) at the start
of a pattern that set overall options that cannot be changed within the
pattern.
(l) PCRE2 recognizes some special sequences such as (*CR) or (*NO_JIT)
at the start of a pattern that set overall options that cannot be
changed within the pattern.
18. The following new Perl 5.26 constructs are not yet supported in
PCRE2:
(a) The Perl /a modifier restricts /d numbers to pure ascii, the new
/aa modifier restricts /i case-insensitive matching to pure ascii also,
ignoring unicode rules. This separation cannot be represented with
PCRE2_UTF.
19. Perl has different limits than PCRE2. See the pcre2limit documenta-
tion for details. Perl went with 5.10 from recursion to iteration keep-
ing the intermediate matches on the heap, which is ~10% slower but does
not fall into any stack-overflow limit. PCRE2 made a similar change at
release 10.30, and also has many build-time and run-time customizable
limits.
AUTHOR
@ -4373,7 +4388,7 @@ AUTHOR
REVISION
Last updated: 03 April 2017
Last updated: 17 April 2017
Copyright (c) 1997-2017 University of Cambridge.
------------------------------------------------------------------------------

35
doc/pcre2compat.3
View File

@ -1,4 +1,4 @@
.TH PCRE2COMPAT 3 "03 April 2017" "PCRE2 10.30"
.TH PCRE2COMPAT 3 "17 April 2017" "PCRE2 10.30"
.SH NAME
PCRE2 - Perl-compatible regular expressions (revised API)
.SH "DIFFERENCES BETWEEN PCRE2 AND PERL"
@ -6,7 +6,7 @@ PCRE2 - Perl-compatible regular expressions (revised API)
.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 5.24, but as both Perl and PCRE2 are continually changing, the
versions 5.26, but as both Perl and PCRE2 are continually changing, the
information may sometimes be out of date.
.P
1. PCRE2 has only a subset of Perl's Unicode support. Details of what it does
@ -125,7 +125,7 @@ letters, regardless of case, when case independence is specified.
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
of which (such as named parentheses) were in PCRE2 for some time before. This
list is with respect to Perl 5.24:
list is with respect to Perl 5.26:
.sp
(a) Although lookbehind assertions in PCRE2 must match fixed length strings,
each alternative branch of a lookbehind assertion can match a different length
@ -148,21 +148,38 @@ question mark they are.
(f) PCRE2_ANCHORED can be used at matching time to force a pattern to be tried
only at the first matching position in the subject string.
.sp
(g) The PCRE2_NOTBOL, PCRE2_NOTEOL, PCRE2_NOTEMPTY, PCRE2_NOTEMPTY_ATSTART, and
PCRE2_NO_AUTO_CAPTURE options have no Perl equivalents.
(g) The PCRE2_NOTBOL, PCRE2_NOTEOL, PCRE2_NOTEMPTY and PCRE2_NOTEMPTY_ATSTART
options have no Perl equivalents.
.sp
(h) The \eR escape sequence can be restricted to match only CR, LF, or CRLF
by the PCRE2_BSR_ANYCRLF option.
.sp
(i) The callout facility is PCRE2-specific.
(i) The callout facility is PCRE2-specific. Perl supports codeblocks and
variable interpolation, but not general hooks on every match.
.sp
(j) The partial matching facility is PCRE2-specific.
.sp
(k) The alternative matching function (\fBpcre2_dfa_match()\fP matches in a
different way and is not Perl-compatible.
.sp
(l) PCRE2 recognizes some special sequences such as (*CR) at the start of
a pattern that set overall options that cannot be changed within the pattern.
(l) PCRE2 recognizes some special sequences such as (*CR) or (*NO_JIT) at
the start of a pattern that set overall options that cannot be changed within
the pattern.
.sp
18. The following new Perl 5.26 constructs are not yet supported in PCRE2:
.sp
(a) The Perl /a modifier restricts /d numbers to pure ascii, the new /aa
modifier restricts /i case-insensitive matching to pure ascii also, ignoring
unicode rules. This separation cannot be represented with PCRE2_UTF.
.sp
19. Perl has different limits than PCRE2. See the
.\" HREF
\fBpcre2limit\fP
.\"
documentation for details. Perl went with 5.10 from recursion to iteration
keeping the intermediate matches on the heap, which is ~10% slower but does not
fall into any stack-overflow limit. PCRE2 made a similar change at release
10.30, and also has many build-time and run-time customizable limits.
.
.
.SH AUTHOR
@ -179,6 +196,6 @@ Cambridge, England.
.rs
.sp
.nf
Last updated: 03 April 2017
Last updated: 17 April 2017
Copyright (c) 1997-2017 University of Cambridge.
.fi