package Mouse::Meta::TypeConstraint;
use Mouse::Util qw(:meta); # enables strict and warnings
-use Scalar::Util ();
sub new {
my $class = shift;
$args{name} = '__ANON__' if !defined $args{name};
- if($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 = $args{parent}{type_parameter})) {
+ if($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 = $args{constraint};
}
sub _add_type_coercions { # ($self, @pairs)
my $self = shift;
+ if(exists $self->{type_constraints}){ # union type
+ $self->throw_error(
+ "Cannot add additional type coercions to Union types '$self'");
+ }
+
my $coercions = ($self->{coercion_map} ||= []);
my %has = map{ $_->[0] => undef } @{$coercions};
push @{$coercions}, [ $type => $action ];
}
- # compile
- if(exists $self->{type_constraints}){ # union type
- $self->throw_error(
- "Cannot add additional type coercions to Union types");
- }
- else{
- $self->_compile_type_coercion();
- }
+ $self->_compile_type_coercion();
return;
}
sub coerce {
my $self = shift;
-
- my $coercion = $self->_compiled_type_coercion;
- if(!$coercion){
- $self->throw_error("Cannot coerce without a type coercion");
- }
-
return $_[0] if $self->check(@_);
+ my $coercion = $self->{_compiled_type_coercion}
+ or $self->throw_error("Cannot coerce without a type coercion");
return $coercion->(@_);
}
}
}
-sub is_a_type_of{
+sub is_a_type_of {
my($self, $other) = @_;
# ->is_a_type_of('__ANON__') is always false
}
# See also Moose::Meta::TypeConstraint::Parameterizable
-sub parameterize{
+sub parameterize {
my($self, $param, $name) = @_;
if(!ref $param){
}
sub _as_string { $_[0]->name } # overload ""
-sub _identity { Scalar::Util::refaddr($_[0]) } # overload 0+
+sub _identity; # overload 0+
sub _unite { # overload infix:<|>
my($lhs, $rhs) = @_;
=head1 VERSION
-This document describes Mouse version 0.71
+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) >>