File Coverage

blib/lib/PPIx/QuoteLike/Token/Delimiter.pm

Criterion	Covered	Total	%
statement	23	23	100.0
branch	4	4	100.0
condition			n/a
subroutine	8	8	100.0
pod	2	2	100.0
total	37	37	100.0

package PPIx::QuoteLike::Token::Delimiter;

use 5.006;

use strict;
use warnings;

use base qw{ PPIx::QuoteLike::Token::Structure };

use PPIx::QuoteLike::Constant qw{ MINIMUM_PERL @CARP_NOT };

our $VERSION = '0.024';

# Perl 5.29.0 disallows unassigned code points and combining code points
# as delimiters. Unfortunately for me non-characters and illegal
# characters are explicitly allowed. Still more unfortunately, these
# match /\p{Unassigned}/. So before I match a deprecated characer, I
# have to assert that the character is neither a non-character
# (\p{Noncharacter_code_point}) nor an illegal Unicode character
# (\P{Any}).
use constant WEIRD_CHAR_RE => eval ## no critic (ProhibitStringyEval,RequireCheckingReturnValueOfEval)
'qr<
    (?! [\p{Noncharacter_code_point}\P{Any}] )
    [\p{Unassigned}\p{Mark}]
>smx';

=head2 perl_version_introduced

Experimentation with weird delimiters shows that they did not actually
work until Perl 5.8.3, so we return C<'5.008003'> for such delimiters.

=cut

sub perl_version_introduced {
    my ( $self ) = @_;
    $self->content() =~ m/ \A [[:^ascii:]] \z /smx
	and return '5.008003';
    return MINIMUM_PERL;
}

=head2 perl_version_removed

Perl 5.29.0 made fatal the use of non-standalone graphemes as string
delimiters. Because non-characters and permanently unassigned code points
are still allowed per F, I take this to mean characters
that match C (i.e. combining diacritical marks).  But this
regular expression does not compile under Perl 5.6.

So:

This method returns C<'5.029'> for such delimiters B the
requisite regular expression compiles. Otherwise it return C.

=cut

sub perl_version_removed {
    my ( $self ) = @_;
    WEIRD_CHAR_RE
	and $self->content() =~ WEIRD_CHAR_RE
	and return '5.029';
    # I respectfully disagree with Perl Best Practices on the
    # following. When this method is called in list context it MUST
    # return undef if that's the right answer, NOT an empty list.
    # Otherwise hash constructors have the wrong number of elements.
    return undef;	## no critic (ProhibitExplicitReturnUndef)
}

1;

__END__