NAME

    Text::Balanced - Extract delimited text sequences from strings.

SYNOPSIS

    use Text::Balanced qw (
        extract_delimited
        extract_bracketed
        extract_quotelike
        extract_codeblock
        extract_variable
        extract_tagged
        extract_multiple
        gen_delimited_pat
        gen_extract_tagged
    );

    # Extract the initial substring of $text that is delimited by
    # two (unescaped) instances of the first character in $delim.

    ($extracted, $remainder) = extract_delimited($text,$delim);

    # Extract the initial substring of $text that is bracketed
    # with a delimiter(s) specified by $delim (where the string
    # in $delim contains one or more of '(){}[]<>').

    ($extracted, $remainder) = extract_bracketed($text,$delim);

    # Extract the initial substring of $text that is bounded by
    # an XML tag.

    ($extracted, $remainder) = extract_tagged($text);

    # Extract the initial substring of $text that is bounded by
    # a C<BEGIN>...C<END> pair. Don't allow nested C<BEGIN> tags

    ($extracted, $remainder) =
        extract_tagged($text,"BEGIN","END",undef,{bad=>["BEGIN"]});

    # Extract the initial substring of $text that represents a
    # Perl "quote or quote-like operation"

    ($extracted, $remainder) = extract_quotelike($text);

    # Extract the initial substring of $text that represents a block
    # of Perl code, bracketed by any of character(s) specified by $delim
    # (where the string $delim contains one or more of '(){}[]<>').

    ($extracted, $remainder) = extract_codeblock($text,$delim);

    # Extract the initial substrings of $text that would be extracted by
    # one or more sequential applications of the specified functions
    # or regular expressions

    @extracted = extract_multiple($text,
                                  [ \&extract_bracketed,
                                    \&extract_quotelike,
                                    \&some_other_extractor_sub,
                                    qr/[xyz]*/,
                                    'literal',
                                  ]);

    # Create a string representing an optimized pattern (a la Friedl)
    # that matches a substring delimited by any of the specified characters
    # (in this case: any type of quote or a slash)

    $patstring = gen_delimited_pat(q{'"`/});

    # Generate a reference to an anonymous sub that is just like extract_tagged
    # but pre-compiled and optimized for a specific pair of tags, and
    # consequently much faster (i.e. 3 times faster). It uses qr// for better
    # performance on repeated calls.

    $extract_head = gen_extract_tagged('<HEAD>','</HEAD>');
    ($extracted, $remainder) = $extract_head->($text);

DESCRIPTION

    The various extract_... subroutines may be used to extract a delimited
    substring, possibly after skipping a specified prefix string. By default,
    that prefix is optional whitespace (/\s*/), but you can change it to
    whatever you wish (see below).

    The substring to be extracted must appear at the current pos location of the
    string's variable (or at index zero, if no pos position is defined). In
    other words, the extract_... subroutines *don't* extract the first
    occurrence of a substring anywhere in a string (like an unanchored regex
    would). Rather, they extract an occurrence of the substring appearing
    immediately at the current matching position in the string (like a
    \G-anchored regex would).

INSTALLATION

    See the INSTALL file.

COPYRIGHT

    Copyright (C) 1997-2001 Damian Conway. All rights reserved.
    Copyright (C) 2009 Adam Kennedy.
    Copyright (C) 2015, 2020 Steve Hay. All rights reserved.

LICENCE

    This distribution is free software; you can redistribute it and/or modify it
    under the same terms as Perl itself, i.e. under the terms of either the GNU
    General Public License or the Artistic License, as specified in the LICENCE
    file.
