#!/usr/bin/env perl
use 5.014;
use warnings;
use open IN => ':utf8', ':std';

our $VERSION = '1.03';

my $di = do "data/digraphs-rfc.inc.pl"
	or warn "official digraphs not included for comparison: ", $@ // $!;

say "# automatically generated by $0";
say '+{';
for (readline) {
	my ($mnem, $cp, $chr) = m{^([!"%'-Z_a-z]{2}) (?:\\(\d+)|(.))} or next;
	warn("$mnem already defined"), next if defined $di->{$mnem};
	my $chrstr = sprintf '"\x{%x}"', $cp // ord $chr;
	say "q{$mnem} => $chrstr,";
}
say '}';

__END__

=head1 NAME

mkdigraphs-shiar - Output digraph data from proposal text

=head1 SYNOPSIS

    mkdigraphs-shiar shiar.inc.txt >digraphs-shiar.inc.pl
    perl -e'$di = do "digraphs-shiar.inc.pl"; print chr $di->{":)"}'

=head1 DESCRIPTION

Parses a text file containing digraphs followed by
the literal unicode character and optional comments.
If successful, Perl code is output resulting in a hash
with Unicode code points keyed by digraph.
Any errors and warnings are given at STDERR.

=head1 AUTHOR

Mischa POSLAWSKY <perl@shiar.org>

=head1 LICENSE

Licensed under the GNU Affero General Public License version 3.