File Coverage

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

Criterion	Covered	Total	%
statement	65	69	94.2
branch	36	48	75.0
condition	11	15	73.3
subroutine	12	15	80.0
pod	4	4	100.0
total	128	151	84.7

=head1 NAME

PPIx::Regexp::Structure::Quantifier - Represent curly bracket quantifiers

=head1 SYNOPSIS

 use PPIx::Regexp::Dumper;
 PPIx::Regexp::Dumper->new( 'qr{fo{2,}}smx' )
     ->print();

=head1 INHERITANCE

C is a
L.

C has no descendants.

=head1 DESCRIPTION

This class represents curly bracket quantifiers such as C<{3}>, C<{3,}>
and C<{3,5}>. The contents are left as literals or interpolations.

B that if they occur inside a variable-length look-behind,
quantifiers with different low and high limits (such as C<'{1,3}'> imply
a minimum Perl version of C<5.29.9>. Quantifiers specifying more than
255 characters are regarded as parse errors and reblessed into the
unknown structure.

=head1 METHODS

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

=cut

package PPIx::Regexp::Structure::Quantifier;

use strict;
use warnings;

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

use Scalar::Util qw{ looks_like_number };

use PPIx::Regexp::Constant qw{
    INFINITY
    LITERAL_LEFT_CURLY_ALLOWED
    MINIMUM_PERL
    MSG_LOOK_BEHIND_TOO_LONG
    STRUCTURE_UNKNOWN
    VARIABLE_LENGTH_LOOK_BEHIND_INTRODUCED
    @CARP_NOT
};

our $VERSION = '0.087';

sub can_be_quantified {
    return;
}

sub explain {
    my ( $self ) = @_;

=begin comment

    my $content = $self->content();
    if ( $content =~ m/ \A [{] ( .*? ) [}] \z /smx ) {
	my $quant = $1;
	my ( $lo, $hi ) = split qr{ , }smx, $quant;
	foreach ( $lo, $hi ) {
	    defined
		or next;
	    s/ \A \s+ //smx;
	    s/ \s+ \z //smx;
	}
	defined $lo
	    and '' ne $lo
	    or $lo = '0';
	defined $hi
	    and '' ne $hi
	    and return "match $lo to $hi times";
	$quant =~ m/ , \z /smx
	    and return "match $lo or more times";
	$lo =~ m/ [^0-9] /smx
	    and return "match $lo times";
	return "match exactly $lo times";
    }
    return $self->SUPER::explain();

=end comment

=cut

    my ( $lo, $hi ) = $self->_min_max();

    if ( looks_like_number( $hi ) ) {
	$hi == INFINITY
	    and return "match $lo or more times";
	looks_like_number( $lo )
	    and $lo == $hi
	    and return "match exactly $lo times";
    } elsif ( $lo eq $hi ) {
	return "match $lo times";
    }
    return "match $lo to $hi times";
}

sub _min_max {
    my ( $self ) = @_;
    my $content = $self->content();
    if ( $content =~ m/ \A [{] ( .*? ) [}] \z /smx ) {
	my $quant = $1;
	my ( $lo, $hi ) = split qr{ , }smx, $quant;
	foreach ( $lo, $hi ) {
	    defined
		or next;
	    s/ \A \s+ //smx;
	    s/ \s+ \z //smx;
	}
	defined $lo
	    and '' ne $lo
	    or $lo = 0;
	defined $hi
	    and '' ne $hi
	    and return ( $lo, $hi );
	$quant =~ m/ , \z /smx
	    and return ( $lo, INFINITY );
	return ( $lo, $lo );
    }
}

sub is_quantifier {
    return 1;
}

sub width {
    return ( 0, 0 );
}

sub __quantified_width {
    my ( $self, $raw_min, $raw_max ) = @_;
    my ( $my_min, $my_max ) = $self->_min_max();
    foreach ( $my_min, $my_max ) {
	looks_like_number( $_ )
	    or $_ = undef;
    }
    defined $raw_min
	and $raw_min = defined $my_min ? $raw_min * $my_min : undef;
    defined $raw_max
	and $raw_max = defined $my_max ? $raw_max * $my_max : undef;
    return ( $raw_min, $raw_max );
}

sub __following_literal_left_curly_disallowed_in {
    return LITERAL_LEFT_CURLY_ALLOWED;
}

sub _too_big {
    my ( $self ) = @_;
    STRUCTURE_UNKNOWN->__PPIX_ELEM__rebless( $self,
	error	=> MSG_LOOK_BEHIND_TOO_LONG,
    );
    return 1;
}

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

    my $content = $self->content();

    if ( $self->__in_look_behind() ) {
	if ( $content =~ m/ \A [{] ( .*? ) [}] \z /smx ) {
	    my $quant = $1;

	    $quant =~ m/ , \z /smx
		and return $self->_too_big();

	    my ( $lo, $hi ) = split qr{ , }smx, $quant;

	    defined $hi
		or $hi = $lo;

	    my $numeric = 1;
	    foreach ( $lo, $hi ) {
		if ( m/ \A [0-9]+ \z /smx ) {
		    $_ >= 256
			and return $self->_too_big();
		} else {
		    $numeric = 0;
		}
	    }

	    if ( $numeric && $lo != $hi ) {

		if ( my $finish = $self->finish() ) {
		    $finish->perl_version_introduced() lt
		    VARIABLE_LENGTH_LOOK_BEHIND_INTRODUCED
			and $finish->{perl_version_introduced} =
		    VARIABLE_LENGTH_LOOK_BEHIND_INTRODUCED;
		}

	    }
	}
    }

    ( $content =~ m/ \s /smx or $content =~ m/ \A \{ , /smx )
	and $self->finish()->{perl_version_introduced} = '5.033006';

    return 0;
}

# Called by the lexer to record the capture number.
sub __PPIX_LEXER__record_capture_number {
    my ( undef, $number ) = @_;		# Invocant unused
    return $number;
}

1;

__END__