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Diffstat (limited to 'doc/pcrepattern.3')
| -rw-r--r-- | doc/pcrepattern.3 | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/doc/pcrepattern.3 b/doc/pcrepattern.3 index 1e25371..c221682 100644 --- a/doc/pcrepattern.3 +++ b/doc/pcrepattern.3 @@ -1,4 +1,4 @@ -.TH PCREPATTERN 3 "14 October 2016" "PCRE 8.40" +.TH PCREPATTERN 3 "23 October 2016" "PCRE 8.40" .SH NAME PCRE - Perl-compatible regular expressions .SH "PCRE REGULAR EXPRESSION DETAILS" @@ -2167,6 +2167,13 @@ numbering the capturing subpatterns in the whole pattern. However, substring capturing is carried out only for positive assertions. (Perl sometimes, but not always, does do capturing in negative assertions.) .P +WARNING: If a positive assertion containing one or more capturing subpatterns +succeeds, but failure to match later in the pattern causes backtracking over +this assertion, the captures within the assertion are reset only if no higher +numbered captures are already set. This is, unfortunately, a fundamental +limitation of the current implementation, and as PCRE1 is now in +maintenance-only status, it is unlikely ever to change. +.P For compatibility with Perl, assertion subpatterns may be repeated; though it makes no sense to assert the same thing several times, the side effect of capturing parentheses may occasionally be useful. In practice, there only three @@ -3292,6 +3299,6 @@ Cambridge CB2 3QH, England. .rs .sp .nf -Last updated: 14 October 2016 +Last updated: 23 October 2016 Copyright (c) 1997-2016 University of Cambridge. .fi |