use strict;
use warnings;
use Algorithm::Loops qw(MapCarE);

MapCarE {
	my ($s, $t) = @_;
	my $x= $t =~ /$s/ ? '~' : '!';
	print "$t $x~ $s\n";
}
[shift =~ /\[\w+\]|\w/g],	# split source into chars or char classes
[split //, shift];		# split target into chars