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Diffstat (limited to 'pcre/doc/pcrematching.3')
| -rw-r--r-- | pcre/doc/pcrematching.3 | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/pcre/doc/pcrematching.3 b/pcre/doc/pcrematching.3 index a9977d5e05a..268baf9b8c6 100644 --- a/pcre/doc/pcrematching.3 +++ b/pcre/doc/pcrematching.3 @@ -1,4 +1,4 @@ -.TH PCREMATCHING 3 "08 January 2012" "PCRE 8.30" +.TH PCREMATCHING 3 "12 November 2013" "PCRE 8.34" .SH NAME PCRE - Perl-compatible regular expressions .SH "PCRE MATCHING ALGORITHMS" @@ -106,6 +106,14 @@ the three strings "caterpillar", "cater", and "cat" that start at the fifth character of the subject. The algorithm does not automatically move on to find matches that start at later positions. .P +PCRE's "auto-possessification" optimization usually applies to character +repeats at the end of a pattern (as well as internally). For example, the +pattern "a\ed+" is compiled as if it were "a\ed++" because there is no point +even considering the possibility of backtracking into the repeated digits. For +DFA matching, this means that only one possible match is found. If you really +do want multiple matches in such cases, either use an ungreedy repeat +("a\ed+?") or set the PCRE_NO_AUTO_POSSESS option when compiling. +.P There are a number of features of PCRE regular expressions that are not supported by the alternative matching algorithm. They are as follows: .P @@ -201,6 +209,6 @@ Cambridge CB2 3QH, England. .rs .sp .nf -Last updated: 08 January 2012 +Last updated: 12 November 2013 Copyright (c) 1997-2012 University of Cambridge. .fi |