2 package Moose::Meta::TypeConstraint;
8 use overload '0+' => sub { refaddr(shift) }, # id an object
9 '""' => sub { shift->name }, # stringify to tc name
13 use Scalar::Util qw(blessed refaddr);
14 use Sub::Name qw(subname);
17 use base qw(Class::MOP::Object);
19 __PACKAGE__->meta->add_attribute('name' => (reader => 'name'));
20 __PACKAGE__->meta->add_attribute('parent' => (
22 predicate => 'has_parent',
25 my $null_constraint = sub { 1 };
26 __PACKAGE__->meta->add_attribute('constraint' => (
27 reader => 'constraint',
28 writer => '_set_constraint',
29 default => sub { $null_constraint }
31 __PACKAGE__->meta->add_attribute('message' => (
32 accessor => 'message',
33 predicate => 'has_message'
35 __PACKAGE__->meta->add_attribute('coercion' => (
36 accessor => 'coercion',
37 predicate => 'has_coercion'
40 __PACKAGE__->meta->add_attribute('hand_optimized_type_constraint' => (
41 init_arg => 'optimized',
42 accessor => 'hand_optimized_type_constraint',
43 predicate => 'has_hand_optimized_type_constraint',
46 __PACKAGE__->meta->add_attribute('inlined' => (
47 accessor => 'inlined',
48 predicate => 'has_inlined_type_constraint',
58 __PACKAGE__->meta->add_attribute('compiled_type_constraint' => (
59 accessor => '_compiled_type_constraint',
60 predicate => '_has_compiled_type_constraint'
62 __PACKAGE__->meta->add_attribute('package_defined_in' => (
63 accessor => '_package_defined_in'
68 my ($first, @rest) = @_;
69 my %args = ref $first ? %$first : $first ? ($first, @rest) : ();
70 $args{name} = $args{name} ? "$args{name}" : "__ANON__";
72 my $self = $class->_new(%args);
73 $self->compile_type_constraint()
74 unless $self->_has_compiled_type_constraint;
83 my $coercion = $self->coercion;
87 Moose->throw_error("Cannot coerce without a type coercion");
90 return $_[0] if $self->check($_[0]);
92 return $coercion->coerce(@_);
98 my $coercion = $self->coercion;
102 Moose->throw_error("Cannot coerce without a type coercion");
105 return $_[0] if $self->check($_[0]);
107 my $result = $coercion->coerce(@_);
109 $self->assert_valid($result);
115 my ($self, @args) = @_;
116 my $constraint_subref = $self->_compiled_type_constraint;
117 return $constraint_subref->(@args) ? 1 : undef;
121 my ($self, $value) = @_;
122 if ($self->_compiled_type_constraint->($value)) {
126 $self->get_message($value);
133 unless ( $self->has_inlined_type_constraint ) {
135 Moose->throw_error( 'Cannot inline a type constraint check for ' . $self->name );
138 return $self->inlined->( $self, @_ );
142 my ($self, $value) = @_;
144 my $error = $self->validate($value);
145 return 1 if ! defined $error;
148 Moose->throw_error($error);
152 my ($self, $value) = @_;
153 if (my $msg = $self->message) {
155 return $msg->($value);
158 # have to load it late like this, since it uses Moose itself
159 my $can_partialdump = try {
160 # versions prior to 0.14 had a potential infinite loop bug
161 Class::MOP::load_class('Devel::PartialDump', { -version => 0.14 });
164 if ($can_partialdump) {
165 $value = Devel::PartialDump->new->dump($value);
168 $value = (defined $value ? overload::StrVal($value) : 'undef');
170 return "Validation failed for '" . $self->name . "' with value $value";
174 ## type predicates ...
177 my ( $self, $type_or_name ) = @_;
179 my $other = Moose::Util::TypeConstraints::find_type_constraint($type_or_name) or return;
181 return 1 if $self == $other;
183 if ( $self->has_hand_optimized_type_constraint and $other->has_hand_optimized_type_constraint ) {
184 return 1 if $self->hand_optimized_type_constraint == $other->hand_optimized_type_constraint;
187 return unless $self->constraint == $other->constraint;
189 if ( $self->has_parent ) {
190 return unless $other->has_parent;
191 return unless $self->parent->equals( $other->parent );
193 return if $other->has_parent;
200 my ($self, $type_or_name) = @_;
202 my $type = Moose::Util::TypeConstraints::find_type_constraint($type_or_name) or return;
204 ($self->equals($type) || $self->is_subtype_of($type));
208 my ($self, $type_or_name) = @_;
210 my $type = Moose::Util::TypeConstraints::find_type_constraint($type_or_name) or return;
214 while (my $parent = $current->parent) {
215 return 1 if $parent->equals($type);
222 ## compiling the type constraint
224 sub compile_type_constraint {
226 $self->_compiled_type_constraint($self->_actually_compile_type_constraint);
229 ## type compilers ...
231 sub _actually_compile_type_constraint {
234 return $self->_compile_hand_optimized_type_constraint
235 if $self->has_hand_optimized_type_constraint;
237 my $check = $self->constraint;
238 unless ( defined $check ) {
240 Moose->throw_error( "Could not compile type constraint '"
242 . "' because no constraint check" );
245 return $self->_compile_subtype($check)
246 if $self->has_parent;
248 return $self->_compile_type($check);
251 sub _compile_hand_optimized_type_constraint {
254 my $type_constraint = $self->hand_optimized_type_constraint;
256 unless ( ref $type_constraint ) {
258 Moose->throw_error("Hand optimized type constraint is not a code reference");
261 return $type_constraint;
264 sub _compile_subtype {
265 my ($self, $check) = @_;
267 # gather all the parent constraintss in order
269 my $optimized_parent;
270 foreach my $parent ($self->_collect_all_parents) {
271 # if a parent is optimized, the optimized constraint already includes
272 # all of its parents tcs, so we can break the loop
273 if ($parent->has_hand_optimized_type_constraint) {
274 push @parents => $optimized_parent = $parent->hand_optimized_type_constraint;
278 push @parents => $parent->constraint;
282 @parents = grep { $_ != $null_constraint } reverse @parents;
284 unless ( @parents ) {
285 return $self->_compile_type($check);
286 } elsif( $optimized_parent and @parents == 1 ) {
287 # the case of just one optimized parent is optimized to prevent
288 # looping and the unnecessary localization
289 if ( $check == $null_constraint ) {
290 return $optimized_parent;
292 return subname($self->name, sub {
293 return undef unless $optimized_parent->($_[0]);
300 # general case, check all the constraints, from the first parent to ourselves
301 my @checks = @parents;
302 push @checks, $check if $check != $null_constraint;
303 return subname($self->name => sub {
306 foreach my $check (@checks) {
307 return undef unless $check->(@args);
315 my ($self, $check) = @_;
317 return $check if $check == $null_constraint; # Item, Any
319 return subname($self->name => sub {
328 sub _collect_all_parents {
331 my $current = $self->parent;
332 while (defined $current) {
333 push @parents => $current;
334 $current = $current->parent;
339 sub create_child_type {
340 my ($self, %opts) = @_;
341 my $class = ref $self;
342 return $class->new(%opts, parent => $self);
347 # ABSTRACT: The Moose Type Constraint metaclass
355 This class represents a single type constraint. Moose's built-in type
356 constraints, as well as constraints you define, are all stored in a
357 L<Moose::Meta::TypeConstraint::Registry> object as objects of this
362 C<Moose::Meta::TypeConstraint> is a subclass of L<Class::MOP::Object>.
368 =item B<< Moose::Meta::TypeConstraint->new(%options) >>
370 This creates a new type constraint based on the provided C<%options>:
376 The constraint name. If a name is not provided, it will be set to
381 A C<Moose::Meta::TypeConstraint> object which is the parent type for
382 the type being created. This is optional.
386 This is the subroutine reference that implements the actual constraint
387 check. This defaults to a subroutine which always returns true.
391 A subroutine reference which is used to generate an error message when
392 the constraint fails. This is optional.
396 A L<Moose::Meta::TypeCoercion> object representing the coercions to
397 the type. This is optional.
401 This is a variant of the C<constraint> parameter that is somehow
402 optimized. Typically, this means incorporating both the type's
403 constraint and all of its parents' constraints into a single
404 subroutine reference.
408 =item B<< $constraint->equals($type_name_or_object) >>
410 Returns true if the supplied name or type object is the same as the
413 =item B<< $constraint->is_subtype_of($type_name_or_object) >>
415 Returns true if the supplied name or type object is a parent of the
418 =item B<< $constraint->is_a_type_of($type_name_or_object) >>
420 Returns true if the given type is the same as the current type, or is
421 a parent of the current type. This is a shortcut for checking
422 C<equals> and C<is_subtype_of>.
424 =item B<< $constraint->coerce($value) >>
426 This will attempt to coerce the value to the type. If the type does not
427 have any defined coercions this will throw an error.
429 If no coercion can produce a value matching C<$constraint>, the original
432 =item B<< $constraint->assert_coerce($value) >>
434 This method behaves just like C<coerce>, but if the result is not valid
435 according to C<$constraint>, an error is thrown.
437 =item B<< $constraint->check($value) >>
439 Returns true if the given value passes the constraint for the type.
441 =item B<< $constraint->validate($value) >>
443 This is similar to C<check>. However, if the type I<is valid> then the
444 method returns an explicit C<undef>. If the type is not valid, we call
445 C<< $self->get_message($value) >> internally to generate an error
448 =item B<< $constraint->assert_valid($value) >>
450 Like C<check> and C<validate>, this method checks whether C<$value> is
451 valid under the constraint. If it is, it will return true. If it is not,
452 an exception will be thrown with the results of
453 C<< $self->get_message($value) >>.
455 =item B<< $constraint->name >>
457 Returns the type's name, as provided to the constructor.
459 =item B<< $constraint->parent >>
461 Returns the type's parent, as provided to the constructor, if any.
463 =item B<< $constraint->has_parent >>
465 Returns true if the type has a parent type.
467 =item B<< $constraint->parents >>
469 A synonym for C<parent>. This is useful for polymorphism with types
470 that can have more than one parent.
472 =item B<< $constraint->constraint >>
474 Returns the type's constraint, as provided to the constructor.
476 =item B<< $constraint->get_message($value) >>
478 This generates a method for the given value. If the type does not have
479 an explicit message, we generate a default message.
481 =item B<< $constraint->has_message >>
483 Returns true if the type has a message.
485 =item B<< $constraint->message >>
487 Returns the type's message as a subroutine reference.
489 =item B<< $constraint->coercion >>
491 Returns the type's L<Moose::Meta::TypeCoercion> object, if one
494 =item B<< $constraint->has_coercion >>
496 Returns true if the type has a coercion.
498 =item B<< $constraint->hand_optimized_type_constraint >>
500 Returns the type's hand optimized constraint, as provided to the
501 constructor via the C<optimized> option.
503 =item B<< $constraint->has_hand_optimized_type_constraint >>
505 Returns true if the type has an optimized constraint.
507 =item B<< $constraint->create_child_type(%options) >>
509 This returns a new type constraint of the same class using the
510 provided C<%options>. The C<parent> option will be the current type.
512 This method exists so that subclasses of this class can override this
513 behavior and change how child types are created.
519 See L<Moose/BUGS> for details on reporting bugs.