File Coverage

blib/lib/PPIx/Regexp/Token/GroupType/Assertion.pm

Criterion	Covered	Total	%
statement	37	39	94.8
branch	4	4	100.0
condition	4	5	80.0
subroutine	12	13	92.3
pod	2	2	100.0
total	59	63	93.6

=head1 NAME

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

=head1 SYNOPSIS

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

=head1 INHERITANCE

C is a
L.

C has no descendants.

=head1 DESCRIPTION

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

=head1 METHODS

This class provides the following public methods beyond those provided
by its superclass.

=cut

package PPIx::Regexp::Token::GroupType::Assertion;

use strict;
use warnings;

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

use PPIx::Regexp::Constant qw{
    COOKIE_LOOKAROUND_ASSERTION
    @CARP_NOT
};

our $VERSION = '0.087';

use constant EXPL_NLA	=> 'Negative look-ahead assertion';
use constant EXPL_NLB	=> 'Negative look-behind assertion';
use constant EXPL_PLA	=> 'Positive look-ahead assertion';
use constant EXPL_PLB	=> 'Positive look-behind assertion';

use constant DEF	=> {

    '?!'	=> {
	expl	=> EXPL_NLA,
	look_ahead	=> 1,
    },
    '*nla:'	=> {
	expl	=> EXPL_NLA,
	intro	=> '5.027009',
	look_ahead	=> 1,
    },
    '*negative_lookahead:'	=> {
	expl	=> EXPL_NLA,
	intro	=> '5.027009',
	look_ahead	=> 1,
    },
    '? {
	expl	=> EXPL_NLB,
	intro	=> '5.005',
    },
    '*nlb:'	=> {
	expl	=> EXPL_NLB,
	intro	=> '5.027009',
    },
    '*negative_lookbehind:'	=> {
	expl	=> EXPL_NLB,
	intro	=> '5.027009',
    },
    '?='	=> {
	expl	=> EXPL_PLA,
	look_ahead	=> 1,
	positive	=> 1,
    },
    '*pla:'	=> {
	expl	=> EXPL_PLA,
	intro	=> '5.027009',
	look_ahead	=> 1,
	positive	=> 1,
    },
    '*positive_lookahead:'	=> {
	expl	=> EXPL_PLA,
	intro	=> '5.027009',
	look_ahead	=> 1,
	positive	=> 1,
    },
    '?<='	=> {
	expl	=> EXPL_PLB,
	intro	=> '5.005',
	positive	=> 1,
    },
    '*plb:'	=> {
	expl	=> EXPL_PLB,
	intro	=> '5.027009',
	positive	=> 1,
    },
    '*positive_lookbehind:'	=> {
	expl	=> EXPL_PLB,
	intro	=> '5.027009',
	positive	=> 1,
    },
};

__PACKAGE__->__setup_class();

sub __match_setup {
    my ( undef, $tokenizer ) = @_;	# $class not used
    $tokenizer->__cookie_exists( COOKIE_LOOKAROUND_ASSERTION )
	and return;
    my $nest_depth = 1;
    $tokenizer->cookie( COOKIE_LOOKAROUND_ASSERTION, sub {
	    my ( undef, $token ) = @_;	# $tokenizer not used
	    $token
		and $token->isa( 'PPIx::Regexp::Token::Structure' )
		and $nest_depth += ( {
		    '('	=> 1,
		    ')'	=> -1,
		}->{ $token->content() } || 0 );
	    return $nest_depth;
	},
    );
    return;
}

=head2 is_look_ahead

This method returns a true value if the assertion is a look-ahead
assertion, or a false value if it is a look-behind assertion.

=cut

sub is_look_ahead {
    my ( $self ) = @_;
    return $self->DEF->{ $self->unescaped_content() }->{look_ahead};
}

=head2 is_positive

This method returns a true value if the assertion is a positive
assertion, or a false value if it is a negative assertion.

=cut

sub is_positive {
    my ( $self ) = @_;
    return $self->DEF->{ $self->unescaped_content() }->{positive};
}

1;

__END__