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Diffstat (limited to 'pod/perltodo.pod')
| -rw-r--r-- | pod/perltodo.pod | 23 |
1 files changed, 0 insertions, 23 deletions
diff --git a/pod/perltodo.pod b/pod/perltodo.pod index 4a54bcddb6..b65009e801 100644 --- a/pod/perltodo.pod +++ b/pod/perltodo.pod @@ -629,29 +629,6 @@ Fix (or rewrite) the implementation of the C</(?{...})/> closures. This will allow the use of a regex from inside (?{ }), (??{ }) and (?(?{ })|) constructs. -=head2 Add possessive quantifiers to regexp engine - -Possessive quantifiers are a syntactic sugar that affords a more -elegant way to express (?>A+). They are also provided by many other -regex engines. Most importantly they allow various patterns to be -optimised more efficiently than (?>...) allows, and allow various data -driven optimisations to be implemented (such as auto-possesification of -quantifiers followed by contrary suffixes). Common syntax for them is - - ++ possessive 1 or more - *+ possessive 0 or more - {n,m}+ possessive n..m - -A possessive quantifier basically absorbs as much as it can and doesn't -give any back. - -Jeffrey Friedl documents possessive quantifiers in Mastering Regular -Expressions 2nd edition and explicitly pleads for them to be added to -perl. We should oblige him, lest he leaves us out of a future edition. -;-) - -demerphq has this on his todo list - =head2 Add (?YES) (?NO) to regexp enigne YES/NO would allow a subpattern to be passed/failed but allow backtracking. |