ken@titan ~/tmp/pm_11155205_uni_char_class
$ ls -l *2*
-rw-r--r-- 1 ken None 1275 Oct 29 01:50 PolyUniCharClass2.pm
-rwxr-xr-x 1 ken None  370 Oct 29 01:42 uni_char_class_2.pl

##</code><code>##

#!/usr/bin/env perl

use strict;
use warnings;
use open OUT => qw{:encoding(UTF-8) :std};

use lib '.'; # DEMO ONLY -- DON'T use in PRODUCTION!
use PolyUniCharClass2;

for my $prefix (qw{In Is If}) {
    for my $class (qw{H L M}) {
        my $cons = "${prefix}Thai${class}Cons";
        print "$cons:\n";
        print @{PolyUniCharClass2::list($cons)}, "\n";
    }
}

##</code><code>##

package PolyUniCharClass2;

use strict;
use warnings;

{
    my %char_class_despatch = (
        InThaiHCons => \&InThaiHCons,
        InThaiLCons => \&InThaiLCons,
        IsThaiHCons => \&InThaiHCons,
        IsThaiLCons => \&InThaiLCons,
    );

    sub list {
        my ($char_class) = @_;

        unless (exists $char_class_despatch{$char_class}) {
            warn "Char class '$char_class' doesn't exist!\n";
            return [];
        }

        return [map chr, @{$char_class_despatch{$char_class}->()}];
    }
}

{
    my $ThaiHCons = [qw{0E02-0E03 0E09 0E10 0E16}];
    my $ThaiLCons = [qw{0E04-0E07 0E0A-0E0D 0E11}];

    my %ThaiCons_expanded;

    sub InThaiHCons {
        return $ThaiCons_expanded{InThaiHCons} ||= _expand($ThaiHCons);
    }

    sub InThaiLCons {
        return $ThaiCons_expanded{InThaiLCons} ||= _expand($ThaiLCons);
    }
}

{
    my $re = qr{^([0-9A-Fa-f]+)-([0-9A-Fa-f]+)$};

    sub _expand {
        my ($code_range_list) = @_;

        my @full_list;

        for my $range (@$code_range_list) {
            if ($range =~ $re) {
                push @full_list, hex($1) .. hex($2);
            }
            else {
                push @full_list, hex $range;
            }
        }

        return [@full_list];
    }
}

1;