katakana.pl

use strict;
use warnings;
use utf8;

use Encode qw/encode/;

my  $judging_katakana_list = {
    ア => qr/^[ア-オ]/,
    カ => qr/^[カ-コ]/,
    サ => qr/^[サ-ソ]/,
    タ => qr/^[タ-ト]/,
    ナ => qr/^[ナ-ノ]/,
    ハ => qr/^[ハ-ホ]/,
    マ => qr/^[マ-モ]/,
    ヤ => qr/^[ヤ-ヨ]/,
    ラ => qr/^[ラ-ロ]/,
    ワ => qr/^[ワ-ン]/,
};

my @katakanas = (
    'アケボノ',
    'シラトリ',
);

for my $katakana ( @katakanas ) {
    my $output = sprintf "%s:%s\n",  judge_katakana($katakana), $katakana;
    print encode('utf8', $output);
}

sub judge_katakana {
    my ($katakana) = @_;

    for my $key ( keys %{$judging_katakana_list} ) {
        my $regexp = $judging_katakana_list->{$key};
        if ( $katakana =~ m{$regexp}xms ) {
            return $key;
        }
    }

    return;
}