diff options
Diffstat (limited to 'pod/perlvar.pod')
| -rw-r--r-- | pod/perlvar.pod | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/pod/perlvar.pod b/pod/perlvar.pod index 8a486b2b74..a211c378ae 100644 --- a/pod/perlvar.pod +++ b/pod/perlvar.pod @@ -324,6 +324,15 @@ C<$+{foo}> is equivalent to C<$1> after the following match: 'foo'=~/(?<foo>foo)/; +The underlying behaviour of %+ is provided by the L<re::Tie::Hash::NamedCapture> +module. + +B<Note:> As C<%-> and C<%+> are tied views into a common internal hash +associated with the last successful regular expression. Therefore mixing +iterative access to them via C<each> may have unpredictable results. +Likewise, if the last successful match changes then the results may be +surprising. + =item HANDLE->input_line_number(EXPR) =item $INPUT_LINE_NUMBER @@ -579,6 +588,40 @@ After a match against some variable $var: =back +=item %- +X<%-> + +Similar to %+, this variable allows access to the named capture +buffers that were defined in the last successful match. It returns +a reference to an array containing one value per buffer of a given +name in the pattern. + + if ('1234'=~/(?<A>1)(?<B>2)(?<A>3)(?<B>4)/) { + foreach my $name (sort keys(%-)) { + my $ary = $-{$name}; + foreach my $idx (0..$#$ary) { + print "\$-{$name}[$idx] : ", + (defined($ary->[$idx]) ? "'$ary->[$idx]'" : "undef"), + "\n"; + } + } + } + +would print out: + + $-{A}[0] : '1' + $-{A}[1] : '3' + $-{B}[0] : '2' + $-{B}[1] : '4' + +The behaviour of %- is implemented via the L<re::Tie::Hash::NamedCapture> module. + +Note that C<%-> and C<%+> are tied views into a common internal hash +associated with the last successful regular expression. Therefore mixing +iterative access to them via C<each> may have unpredictable results. +Likewise, if the last successful match changes then the results may be +surprising. + =item HANDLE->format_name(EXPR) =item $FORMAT_NAME |