#! /usr/bin/perl

use warnings;
use 5.010;

sub enumerate {
    my ($property, $key) = @_;

    state (%hash, %enum);

    $hash{$property}{$key} //= ++$enum{$property};
}

print "\n", "Edibles:\n";
print "$_ => @{[enumerate edible => $_]}\n" for
        qw( apple spam pear orange spam spam spam kebab spam caterpillar );

print "\n", "Colors:\n";
print "$_ => @{[enumerate color => $_]}\n" for
        qw( red yellow red red red green );