$args{name} = '__ANON__' if !defined $args{name};
- if(defined $args{parent}) {
+ my $type_parameter;
+ if(defined $args{parent}) { # subtyping
%args = (%{$args{parent}}, %args);
+
# a child type must not inherit 'compiled_type_constraint'
# and 'hand_optimized_type_constraint' from the parent
- delete $args{compiled_type_constraint};
- delete $args{hand_optimized_type_constraint};
+ delete $args{compiled_type_constraint}; # don't inherit it
+ delete $args{hand_optimized_type_constraint}; # don't inherit it
+
+ $type_parameter = $args{type_parameter};
if(defined(my $parent_tp = $args{parent}{type_parameter})) {
- delete $args{type_parameter} if $parent_tp == $args{type_parameter};
+ if($parent_tp != $type_parameter) {
+ $type_parameter->is_a_type_of($parent_tp)
+ or $class->throw_error(
+ "$type_parameter is not a subtype of $parent_tp",
+ );
+ }
+ else {
+ $type_parameter = undef;
+ }
}
}
my $check;
- if($check = delete $args{optimized}) {
+ if($check = delete $args{optimized}) { # likely to be builtins
$args{hand_optimized_type_constraint} = $check;
$args{compiled_type_constraint} = $check;
}
- elsif(my $param = $args{type_parameter}) {
+ elsif(defined $type_parameter) { # parameterizing
my $generator = $args{constraint_generator}
- || $class->throw_error("The $args{name} constraint cannot be used,"
- . " because $param doesn't subtype from a parameterizable type");
- # it must be 'constraint'
- $check = $args{constraint} = $generator->($param);
+ || $class->throw_error(
+ "The $args{name} constraint cannot be used,"
+ . " because $type_parameter doesn't subtype"
+ . " from a parameterizable type");
+
+ my $parameterized_check = $generator->($type_parameter);
+ if(defined(my $my_check = $args{constraint})) {
+ $check = sub {
+ return $parameterized_check->($_) && $my_check->($_);
+ };
+ }
+ else {
+ $check = $parameterized_check;
+ }
+ $args{constraint} = $check;
}
- else {
+ else { # common cases
$check = $args{constraint};
}
return 1;
}
-sub _as_string { $_[0]->name } # overload ""
-sub _identity; # overload 0+
+# overloading stuff
+
+sub _as_string { $_[0]->name } # overload ""
+sub _identity; # overload 0+
sub _unite { # overload infix:<|>
my($lhs, $rhs) = @_;
=head1 VERSION
-This document describes Mouse version 0.78
+This document describes Mouse version 0.82
=head1 DESCRIPTION
=item C<< $constraint->message >>
-=item C<< $constraint->is_a_subtype_of($name or $object) >>
+=item C<< $constraint->is_a_type_of($name or $object) >>
=item C<< $constraint->coerce($value) >>