Implementation of each_with_index in Perl

each_with_index.pl

#!perl
use strict;
use warnings;

sub each_with_index (\@) {
    my $array_ref = shift;

    my $length = scalar @{$array_ref};

    my $index = 0;
    return sub {
        return if $index >= $length;
        my $elem = $array_ref->[$index];
        return wantarray ? ($elem, $index++) : $elem;
    };
}

my @alphabets = 'a'..'z';
my $iter = each_with_index(@alphabets);
while (my ($char, $index) = $iter->()) {
    printf "'%s' is %2d\n", $char, $index;
}