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Diffstat (limited to 'pod')
| -rw-r--r-- | pod/perlre.pod | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/pod/perlre.pod b/pod/perlre.pod index d913c8074a..5287965fe3 100644 --- a/pod/perlre.pod +++ b/pod/perlre.pod @@ -711,6 +711,29 @@ is equivalent to the more verbose /(?:(?s-i)more.*than).*million/i +=item C<(?|pattern)> +X<(?|)> X<Branch reset> + +This is the "branch reset" pattern, which has the special property +that the capture buffers are numbered from the same starting point +in each branch. + +Normally capture buffers in a pattern are number sequentially, left +to right in the pattern. Inside of this construct this behaviour is +overriden so that the captures buffers in each branch share the same +numbers. The numbering in each branch will be as normal, and any +buffers following the use of this pattern will be numbered as though +the construct contained only one branch, that being the one with the +most capture buffers in it. + +Consider the following pattern. The numbers underneath are which +buffer number the captured content will be stored in. + + + # before ---------------branch-reset----------- after + / ( a ) (?| x ( y ) z | (p (q) r) | (t) u (v) ) ( z ) /x + # 1 2 2 3 2 3 4 + =item Look-Around Assertions X<look-around assertion> X<lookaround assertion> X<look-around> X<lookaround> |