File Coverage

blib/lib/Syntax/Feature/KeysOnArray.pm

Criterion	Covered	Total	%
statement	21	30	70.0
branch	1	6	16.6
condition	0	3	0.0
subroutine	7	8	87.5
pod	0	2	0.0
total	29	49	59.1

package Syntax::Feature::KeysOnArray; # so as not to confuse dzil?
our $VERSION = '0.04'; # VERSION
use strict;
use warnings;
use Syntax::Feature::EachOnArray ();
use Carp;
use Scalar::Util qw(reftype);

package Tie::ArrayAsHash;

sub akeys (\[@%]) {
    my $thing = shift;
    return keys %$thing
        if reftype $thing eq 'HASH';
    confess "should be passed a HASH or ARRAY"
        unless reftype $thing eq 'ARRAY';

    my $thing_h = $Tie::ArrayAsHash::cache{$thing} ||= do {
        tie my %h, __PACKAGE__, $thing;
        \%h
    };

    keys %$thing_h;
}

package Syntax::Feature::KeysOnArray;

sub install {
    my $class = shift;
    my %args = @_;

    return unless $^V lt 5.12.0;
    no strict 'refs';
    *{"$args{into}::keys"} = \&Tie::ArrayAsHash::akeys;
}

# XXX on uninstall, delete symbol

1;
# ABSTRACT: Emulate keys(@array) on Perl < 5.12


__END__