use strict;
use warnings;
use Unicode::Normalize qw( NFKD );
use Text::Unidecode qw( unidecode );

our %rows;
my %g; # present group classes
{
	rows => [1, 0],
	def => {
		'' => {
			map {
				my $v = $rows{$_};
				my $class = (
					  !defined $v || $_ eq $v ? 1 # identical
					: $v =~ /\A\p{Mn}+\z/ ? 9 # combining accent
					: $v =~ /\A[\p{Sk}\p{Lm}]+\z/ ? 8 # modifier symbol
					: $v =~ /\A[\pM\pP]+\z/ ? 7 # mark
					: NFKD($v) =~ /\Q$_/ ? 2 # decomposed equivalent
					: unidecode($v) =~ /\Q$_\E+/i ? 4 # transliterated
					: $v =~ /^\p{Latin}/ ? 5 # latin script
					: 6
				);
				$g{$class} = 1;
				$_ => "g$class"
			} keys %rows
		},
	},
	key => \%rows,
	flag => {
		g1 => ['unaltered', "same results as without modifier"],
		g2 => ['accented', "decomposes to the original letter with a combining accent"],
		g4 => ['similar', "transliterates (mostly) into the unmodified letter"],
		g5 => ['latin', "a different (accented) latin letter"],
		g6 => ['symbol', "other character not directly deducible from key"],
		g7 => ['punctuation', "(punctuation) mark"],
			!$g{9} ? () : (
		g8 => ['mark', "modifier letter or mark (spacing diacritic)"],
		g9 => ['combining', "diacritical mark to be combined with a following character"],
			),
	},
}
