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Diffstat (limited to 'pod/perlre.pod')
| -rw-r--r-- | pod/perlre.pod | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/pod/perlre.pod b/pod/perlre.pod index f696525155..6ecb7ad12a 100644 --- a/pod/perlre.pod +++ b/pod/perlre.pod @@ -399,6 +399,28 @@ checks, thus to allow $re in the above snippet to contain C<(?{})> I<with tainting enabled>, one needs both C<use re 'eval'> and untaint the $re. +=item C<(?p{ code })> + +I<Very experimental> "postponed" regular subexpression. C<code> is evaluated +at runtime, at the moment this subexpression may match. The result of +evaluation is considered as a regular expression, and matched as if it +were inserted instead of this construct. + +C<code> is not interpolated. Currently the rules to +determine where the C<code> ends are somewhat convoluted. + +The following regular expression matches matching parenthesized group: + + $re = qr{ + \( + (?: + (?> [^()]+ ) # Non-parens without backtracking + | + (?p{ $re }) # Group with matching parens + )* + \) + }x; + =item C<(?E<gt>pattern)> An "independent" subexpression. Matches the substring that a |