gistfile1.txt

      while(%type_constraints) {
                my($key, $type_constraint) = each %type_constraints;
                delete $type_constraints{$key};
                if(exists $values{$key}) {
                    my $value = $values{$key};
                    delete $values{$key};
                    unless($type_constraint->check($value)) {
                        my $message = $type_constraint->get_message($value);
warn "check $value for ".$type_constraint->name;

                        if(ref $_[2]) {
                            push @{$_[2]->{message}}, $type_constraint->get_message($value)
                             if ref $_[2];
                            return;
                        } else {
warn "no place to stick $message";
return;
                        }
                    }
                }