PPIx::Regexp::Token::GroupType::Assertion - Represent a look ahead or look behind assertion

PPIx-Regexp documentation Contained in the PPIx-Regexp distribution.

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NAME

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PPIx::Regexp::Token::GroupType::Assertion - Represent a look ahead or look behind assertion

SYNOPSIS

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 use PPIx::Regexp::Dumper;
 PPIx::Regexp::Dumper->new( 'qr{foo(?=bar)}smx' )
     ->print();

INHERITANCE

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PPIx::Regexp::Token::GroupType::Assertion is a PPIx::Regexp::Token::GroupType.

PPIx::Regexp::Token::GroupType::Assertion has no descendants.

DESCRIPTION

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This class represents the parenthesized look ahead and look behind assertions.

METHODS

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This class provides no public methods beyond those provided by its superclass.

SUPPORT

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Support is by the author. Please file bug reports at http://rt.cpan.org, or in electronic mail to the author.

AUTHOR

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Thomas R. Wyant, III wyant at cpan dot org

COPYRIGHT AND LICENSE

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Copyright (C) 2009-2011 by Thomas R. Wyant, III

This program is free software; you can redistribute it and/or modify it under the same terms as Perl 5.10.0. For more details, see the full text of the licenses in the directory LICENSES.

This program is distributed in the hope that it will be useful, but without any warranty; without even the implied warranty of merchantability or fitness for a particular purpose.

PPIx-Regexp documentation Contained in the PPIx-Regexp distribution. 
package PPIx::Regexp::Token::GroupType::Assertion;

use strict;
use warnings;

use base qw{ PPIx::Regexp::Token::GroupType };

use PPIx::Regexp::Constant qw{ MINIMUM_PERL };

our $VERSION = '0.020';

{
    my %perl_version_introduced = (
	'?<='	=> '5.005',
	'?<!'	=> '5.005',
    );

    sub perl_version_introduced {
	my ( $self ) = @_;
	return $perl_version_introduced{ $self->content() } || MINIMUM_PERL;
    }
}

# Return true if the token can be quantified, and false otherwise
# sub can_be_quantified { return };

sub __PPIX_TOKENIZER__regexp {
    my ( $class, $tokenizer, $character ) = @_;

    # The actual expression being matched is \A \? <? [=!]. All the
    # optional escapes are because any of the non-open-bracket
    # punctuation characters may itself be escaped if it is also used to
    # quote the entire expression.
    if ( my $assert = $tokenizer->find_regexp(
	    qr{ \A \\? \? <? \\? [=!] }smx ) ) {
	return $assert;
    }

    return;
}

1;

__END__


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