Lines Matching full:perl

3 PCRE2 - Perl-compatible regular expressions (revised API)
4 .SH "DIFFERENCES BETWEEN PCRE2 AND PERL"
8 and Perl handle regular expressions. The differences described here are with
9 respect to Perl version 5.38.0, but as both Perl and PCRE2 are continually
12 1. When PCRE2_DOTALL (equivalent to Perl's /s qualifier) is not set, the
13 behaviour of the '.' metacharacter differs from Perl. In PCRE2, '.' matches the
17 EBCDIC. In Perl, '.' appears never to match LF, even when 0x0A is not a newline
20 2. PCRE2 has only a subset of Perl's Unicode support. Details of what it does
27 3. Like Perl, PCRE2 allows repeat quantifiers on parenthesized assertions, but
31 assertion just once). Perl allows some repeat quantifiers on other assertions,
37 Perl treats the quantifier characters as literal.
42 Perl may set such capture groups in other circumstances.
44 6. The following Perl escape sequences are not supported: \eF, \el, \eL, \eu,
48 implemented by Perl's general string-handling and are not part of its pattern
54 7. The Perl escape sequences \ep, \eP, and \eX are supported only if PCRE2 is
59 Perl support the Cs (surrogate) property, but in PCRE2 its use is limited. See
64 documentation for details. The long synonyms for property names that Perl
70 Perl in that $ and @ are also handled as literals inside the quotes. In Perl,
71 they cause variable interpolation (PCRE2 does not have variables). Also, Perl
77     Pattern            PCRE2 matches     Perl matches
88 by both PCRE2 and Perl.
100 backtracking into subroutine calls is now supported, as in Perl.
105 not always the case in Perl. In particular, if (*THEN) is present in a group
113 triggers (*PRUNE). Perl's behaviour is more complex; in many cases it is the
118 the pattern /^(a(b)?)+$/ in Perl leaves $2 unset, but in PCRE2 it is set to
122 general as Perl's. This is a consequence of the fact the PCRE2 works internally
130 15. Perl used to recognize comments in some places that PCRE2 does not, for
132 set, Perl allowed white space between ( and ? though the latest Perls give an
134 Perl behaves differently.
136 16. Perl, when in warning mode, gives warnings for character classes such as
143 always matches an upper case letter. I think Perl has changed in this respect;
147 18. From release 5.32.0, Perl locks out the use of \eK in lookaround
153 19. PCRE2 provides some extensions to the Perl regular expression facilities.
154 Perl 5.10 included new features that were not in earlier versions of Perl, some
156 list is with respect to Perl 5.38:
161 (b) A backslash followed by a letter with no special meaning is faulted. (Perl
172 options have no Perl equivalents.
177 (g) The callout facility is PCRE2-specific. Perl supports codeblocks and
183 different way and is not Perl-compatible.
190 extension to the lookaround facilities. The default, Perl-compatible
196 numbers such as +2 and -4 in all three cases. Perl supports both plus and minus
200 20. Perl has different limits than PCRE2. See the
204 documentation for details. Perl went with 5.10 from recursion to iteration
209 21. Unlike Perl, PCRE2 doesn't have character set modifiers and specially no way
210 to set characters by context just like Perl's "/d". A regular expression using
211 PCRE2_UTF and PCRE2_UCP will use similar rules to Perl's "/u"; something closer
214 22. Some recursive patterns that Perl diagnoses as infinite recursions can be