1 package Mouse::Meta::TypeConstraint;
2 use Mouse::Util qw(:meta); # enables strict and warnings
6 my %args = @_ == 1 ? %{$_[0]} : @_;
8 $args{name} = '__ANON__' if !defined $args{name};
11 if(defined $args{parent}) { # subtyping
12 %args = (%{$args{parent}}, %args);
14 # a child type must not inherit 'compiled_type_constraint'
15 # and 'hand_optimized_type_constraint' from the parent
16 delete $args{compiled_type_constraint}; # don't inherit it
17 delete $args{hand_optimized_type_constraint}; # don't inherit it
19 $type_parameter = $args{type_parameter};
20 if(defined(my $parent_tp = $args{parent}{type_parameter})) {
21 if($parent_tp != $type_parameter) {
22 $type_parameter->is_a_type_of($parent_tp)
23 or $class->throw_error(
24 "$type_parameter is not a subtype of $parent_tp",
28 $type_parameter = undef;
35 if($check = delete $args{optimized}) { # likely to be builtins
36 $args{hand_optimized_type_constraint} = $check;
37 $args{compiled_type_constraint} = $check;
39 elsif(defined $type_parameter) { # parameterizing
40 my $generator = $args{constraint_generator}
41 || $class->throw_error(
42 "The $args{name} constraint cannot be used,"
43 . " because $type_parameter doesn't subtype"
44 . " from a parameterizable type");
46 my $parameterized_check = $generator->($type_parameter);
47 if(defined(my $my_check = $args{constraint})) {
49 return $parameterized_check->($_) && $my_check->($_);
53 $check = $parameterized_check;
55 $args{constraint} = $check;
58 $check = $args{constraint};
61 if(defined($check) && ref($check) ne 'CODE'){
63 "Constraint for $args{name} is not a CODE reference");
66 my $self = bless \%args, $class;
67 $self->compile_type_constraint()
68 if !$args{hand_optimized_type_constraint};
70 if($args{type_constraints}) {
71 $self->_compile_union_type_coercion();
76 sub create_child_type {
78 return ref($self)->new(@_, parent => $self);
89 sub __is_parameterized;
91 sub _compiled_type_constraint;
92 sub _compiled_type_coercion;
94 sub compile_type_constraint;
97 sub _add_type_coercions { # ($self, @pairs)
100 if(exists $self->{type_constraints}){ # union type
102 "Cannot add additional type coercions to Union types '$self'");
105 my $coercion_map = ($self->{coercion_map} ||= []);
106 my %has = map{ $_->[0]->name => undef } @{$coercion_map};
108 for(my $i = 0; $i < @_; $i++){
110 my $action = $_[++$i];
112 if(exists $has{$from}){
113 $self->throw_error("A coercion action already exists for '$from'");
116 my $type = Mouse::Util::TypeConstraints::find_or_parse_type_constraint($from)
117 or $self->throw_error(
118 "Could not find the type constraint ($from) to coerce from");
120 push @{$coercion_map}, [ $type => $action ];
123 $self->_compile_type_coercion();
127 sub _compile_type_coercion {
132 foreach my $pair(@{$self->{coercion_map}}) {
133 push @coercions, [ $pair->[0]->_compiled_type_constraint, $pair->[1] ];
136 $self->{_compiled_type_coercion} = sub {
138 foreach my $pair (@coercions) {
139 #my ($constraint, $converter) = @$pair;
140 if ($pair->[0]->($thing)) {
142 return $pair->[1]->($thing);
150 sub _compile_union_type_coercion {
154 foreach my $type(@{$self->{type_constraints}}){
155 if($type->has_coercion){
156 push @coercions, $type;
160 $self->{_compiled_type_coercion} = sub {
162 foreach my $type(@coercions){
163 my $value = $type->coerce($thing);
164 return $value if $self->check($value);
174 return $_[0] if $self->check(@_);
176 my $coercion = $self->{_compiled_type_coercion}
177 or $self->throw_error("Cannot coerce without a type coercion");
178 return $coercion->(@_);
182 my ($self, $value) = @_;
183 if ( my $msg = $self->message ) {
185 return $msg->($value);
188 if(not defined $value) {
191 elsif( ref($value) && defined(&overload::StrVal) ) {
192 $value = overload::StrVal($value);
194 return "Validation failed for '$self' with value $value";
199 my($self, $other) = @_;
201 # ->is_a_type_of('__ANON__') is always false
202 return 0 if !ref($other) && $other eq '__ANON__';
204 (my $other_name = $other) =~ s/\s+//g;
206 return 1 if $self->name eq $other_name;
208 if(exists $self->{type_constraints}){ # union
209 foreach my $type(@{$self->{type_constraints}}) {
210 return 1 if $type->name eq $other_name;
214 for(my $p = $self->parent; defined $p; $p = $p->parent) {
215 return 1 if $p->name eq $other_name;
221 # See also Moose::Meta::TypeConstraint::Parameterizable
223 my($self, $param, $name) = @_;
226 require Mouse::Util::TypeConstraints;
227 $param = Mouse::Util::TypeConstraints::find_or_create_isa_type_constraint($param);
230 $name ||= sprintf '%s[%s]', $self->name, $param->name;
231 return Mouse::Meta::TypeConstraint->new(
234 type_parameter => $param,
239 my ($self, $value) = @_;
241 if(!$self->check($value)){
242 $self->throw_error($self->get_message($value));
249 sub _as_string { $_[0]->name } # overload ""
250 sub _identity; # overload 0+
252 sub _unite { # overload infix:<|>
254 require Mouse::Util::TypeConstraints;
255 return Mouse::Util::TypeConstraints::find_or_parse_type_constraint(
265 Mouse::Meta::TypeConstraint - The Mouse Type Constraint metaclass
269 This document describes Mouse version 0.86
273 This class represents a type constraint, including built-in
274 type constraints, union type constraints, parameterizable/
275 parameterized type constraints, as well as custom type
282 =item C<< Mouse::Meta::TypeConstraint->new(%options) >>
284 =item C<< $constraint->name >>
286 =item C<< $constraint->parent >>
288 =item C<< $constraint->constraint >>
290 =item C<< $constraint->has_coercion >>
292 =item C<< $constraint->message >>
294 =item C<< $constraint->is_a_type_of($name or $object) >>
296 =item C<< $constraint->coerce($value) >>
298 =item C<< $constraint->check($value) >>
300 =item C<< $constraint->assert_valid($value) >>
302 =item C<< $constraint->get_message($value) >>
304 =item C<< $constraint->create_child_type(%options) >>
310 L<Moose::Meta::TypeConstraint>