1Regexp::Common::balanceUds(e3r)Contributed Perl DocumentRaetgieoxnp::Common::balanced(3)
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NAME

6       Regexp::Common::balanced -- provide regexes for strings with balanced
7       parenthesized delimiters or arbitrary delimiters.
8

SYNOPSIS

10           use Regexp::Common qw /balanced/;
11
12           while (<>) {
13               /$RE{balanced}{-parens=>'()'}/
14                                          and print q{balanced parentheses\n};
15           }
16

DESCRIPTION

18       Please consult the manual of Regexp::Common for a general description
19       of the works of this interface.
20
21       Do not use this module directly, but load it via Regexp::Common.
22
23       $RE{balanced}{-parens}
24
25       Returns a pattern that matches a string that starts with the nominated
26       opening parenthesis or bracket, contains characters and properly nested
27       parenthesized subsequences, and ends in the matching parenthesis.
28
29       More than one type of parenthesis can be specified:
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31               $RE{balanced}{-parens=>'(){}'}
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33       in which case all specified parenthesis types must be correctly bal‐
34       anced within the string.
35
36       If we are using C{-keep} (See Regexp::Common):
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38       $1  captures the entire expression
39
40       $RE{balanced}{-begin => "begin"}{-end => "end"}
41
42       Returns a pattern that matches a string that is properly balanced using
43       the begin and end strings as start and end delimiters.  Multiple sets
44       of begin and end strings can be given by separating them by "⎪"s (which
45       can be escaped with a backslash).
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47           qr/$RE{balanced}{-begin => "do⎪if⎪case"}{-end => "done⎪fi⎪esac"}/
48
49       will match properly balanced strings that either start with do and end
50       with done, start with if and end with fi, or start with case and end
51       with esac.
52
53       If -end contains less cases than -begin, the last case of -end is
54       repeated. If it contains more cases than -begin, the extra cases are
55       ignored. If either of -begin or -end isn't given, or is empty, -begin
56       => '(' and -end => ')' are assumed.
57
58       If we are using C{-keep} (See Regexp::Common):
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60       $1  captures the entire expression
61

HISTORY

63        $Log: balanced.pm,v $
64        Revision 2.101  2003/02/01 22:55:31  abigail
65        Changed Copyright years
66
67        Revision 2.100  2003/01/21 23:19:40  abigail
68        The whole world understands RCS/CVS version numbers, that 1.9 is an
69        older version than 1.10. Except CPAN. Curse the idiot(s) who think
70        that version numbers are floats (in which universe do floats have
71        more than one decimal dot?).
72        Everything is bumped to version 2.100 because CPAN couldn't deal
73        with the fact one file had version 1.10.
74
75        Revision 1.6  2002/08/20 15:20:48  abigail
76        Documented -begin and -end
77
78        Revision 1.5  2002/08/08 23:57:33  abigail
79        Added HISTORY section.
80
81        Revision 1.4  2002/08/08 23:53:54  abigail
82        Reworked and extended $RE{balanced}. It now takes multiple arbitrary
83        length delimiters. -parens is just a short-cut for some of the common,
84        simpler cases.
85
86        Revision 1.3  2002/08/05 12:16:58  abigail
87        Fixed 'Regex::' and 'Rexexp::' typos to 'Regexp::'
88        (Found my Mike Castle).
89
90        Revision 1.2  2002/07/25 22:37:44  abigail
91        Added 'use strict'.
92        Added 'no_defaults' to 'use Regexp::Common' to prevent loaded of all
93        defaults.
94
95        Revision 1.1  2002/07/25 22:14:44  abigail
96        Factored out from Regexp::Common.
97

SEE ALSO

99       Regexp::Common for a general description of how to use this interface.
100

AUTHOR

102       Damian Conway (damian@conway.org)
103

MAINTAINANCE

105       This package is maintained by Abigail (regexp-common@abigail.nl).
106

BUGS AND IRRITATIONS

108       Bound to be plenty.
109
110       For a start, there are many common regexes missing.  Send them in to
111       regexp-common@abigail.nl.
112

114            Copyright (c) 2001 - 2003, Damian Conway. All Rights Reserved.
115              This module is free software. It may be used, redistributed
116             and/or modified under the terms of the Perl Artistic License
117                   (see http://www.perl.com/perl/misc/Artistic.html)
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121perl v5.8.8                       2003-03-23       Regexp::Common::balanced(3)
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