File Coverage

blib/lib/PPIx/Regexp/Structure/Switch.pm

Criterion	Covered	Total	%
statement	36	36	100.0
branch	16	18	88.8
condition	5	9	55.5
subroutine	6	6	100.0
pod			n/a
total	63	69	91.3

=head1 NAME

PPIx::Regexp::Structure::Switch - Represent a switch

=head1 SYNOPSIS

 use PPIx::Regexp::Dumper;
 PPIx::Regexp::Dumper->new( 'qr{(?(1)foo|bar)}smx' )
     ->print();

=head1 INHERITANCE

C is a
L.

C has no descendants.

=head1 DESCRIPTION

This class represents a switch, or conditional expression. The condition
will be the first child.

=head1 METHODS

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

=cut

package PPIx::Regexp::Structure::Switch;

use strict;
use warnings;

use base qw{ PPIx::Regexp::Structure };

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

our $VERSION = '0.087';

sub __raw_width {
    my ( $self ) = @_;
    my $cond;
    $cond = $self->schild( 0 )
	and $cond->isa( 'PPIx::Regexp::Token::Condition' )
	and $cond->content() eq '(DEFINE)'
	and return ( 0, 0, 1 );
    my ( $node_min, $node_max, $alternatives ) = $self->SUPER::__raw_width();
    defined $node_min
	and $alternatives < 2
	and $node_min = 0;
    return ( $node_min, $node_max, $alternatives );
}

sub __PPIX_LEXER__finalize {
    my ( $self, $lexer ) = @_;

    # Assume no errors.
    my $rslt = 0;

    # Number of allowed alternations not known yet.
    my $alternations;

    # If we are a valid switch, the first child is the condition. Make
    # sure we have a first child and that it is of the expected class.
    # If it is, determine how many alternations are allowed.
    if ( my $condition = $self->child( 0 ) ) {
	foreach my $class ( qw{
	    PPIx::Regexp::Structure::Assertion
	    PPIx::Regexp::Structure::Code
	    PPIx::Regexp::Token::Condition
	    } ) {
	    $condition->isa( $class ) or next;
	    $alternations = $condition->content() eq '(DEFINE)' ? 0 : 1;
	    last;
	}
    }

    if ( defined $alternations ) {
	# If we figured out how many alternations were allowed, count
	# them, changing surplus ones to the unknown token.
	foreach my $kid ( $self->children () ) {
	    $kid->isa( 'PPIx::Regexp::Token::Operator' ) or next;
	    $kid->content() eq '|' or next;
	    --$alternations >= 0 and next;
	    $kid->__error( 'Too many alternatives for switch' );
	}
    } else {
	# If we could not figure out how many alternations were allowed,
	# it means we did not understand our condition. Rebless
	# ourselves to the unknown structure and count a parse failure.
	$self->__error( 'Switch condition not understood' );
	$rslt++;
    }

    # Delegate to the superclass to finalize our children, now that we
    # have finished messing with them.
    $rslt += $self->SUPER::__PPIX_LEXER__finalize( $lexer );

    return $rslt;
}

1;

__END__