xref: /openbsd-src/gnu/usr.bin/perl/ext/Tie-Hash-NamedCapture/NamedCapture.pm (revision de8cc8edbc71bd3e3bc7fbffa27ba0e564c37d8b)
1use strict;
2package Tie::Hash::NamedCapture;
3
4our $VERSION = "0.13";
5
6__END__
7
8=head1 NAME
9
10Tie::Hash::NamedCapture - Named regexp capture buffers
11
12=head1 SYNOPSIS
13
14    tie my %hash, "Tie::Hash::NamedCapture";
15    # %hash now behaves like %+
16
17    tie my %hash, "Tie::Hash::NamedCapture", all => 1;
18    # %hash now access buffers from regexp in $qr like %-
19
20=head1 DESCRIPTION
21
22This module is used to implement the special hashes C<%+> and C<%->, but it
23can be used to tie other variables as you choose.
24
25When the C<all> parameter is provided, then the tied hash elements will be
26array refs listing the contents of each capture buffer whose name is the
27same as the associated hash key. If none of these buffers were involved in
28the match, the contents of that array ref will be as many C<undef> values
29as there are capture buffers with that name. In other words, the tied hash
30will behave as C<%->.
31
32When the C<all> parameter is omitted or false, then the tied hash elements
33will be the contents of the leftmost defined buffer with the name of the
34associated hash key. In other words, the tied hash will behave as
35C<%+>.
36
37The keys of C<%->-like hashes correspond to all buffer names found in the
38regular expression; the keys of C<%+>-like hashes list only the names of
39buffers that have captured (and that are thus associated to defined values).
40
41This implementation has been moved into the core executable, but you
42can still load this module for backward compatibility.
43
44=head1 SEE ALSO
45
46L<perlreapi>, L<re>, L<perlmodlib/Pragmatic Modules>, L<perlvar/"%+">,
47L<perlvar/"%-">.
48
49=cut
50