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 die 'Cannot inline a type constraint check for ' . $self->name
134 unless $self->has_inlined_type_constraint;
136 return $self->inlined->( $self, @_ );
140 my ($self, $value) = @_;
142 my $error = $self->validate($value);
143 return 1 if ! defined $error;
146 Moose->throw_error($error);
150 my ($self, $value) = @_;
151 if (my $msg = $self->message) {
153 return $msg->($value);
156 # have to load it late like this, since it uses Moose itself
157 my $can_partialdump = try {
158 # versions prior to 0.14 had a potential infinite loop bug
159 Class::MOP::load_class('Devel::PartialDump', { -version => 0.14 });
162 if ($can_partialdump) {
163 $value = Devel::PartialDump->new->dump($value);
166 $value = (defined $value ? overload::StrVal($value) : 'undef');
168 return "Validation failed for '" . $self->name . "' with value $value";
172 ## type predicates ...
175 my ( $self, $type_or_name ) = @_;
177 my $other = Moose::Util::TypeConstraints::find_type_constraint($type_or_name) or return;
179 return 1 if $self == $other;
181 if ( $self->has_hand_optimized_type_constraint and $other->has_hand_optimized_type_constraint ) {
182 return 1 if $self->hand_optimized_type_constraint == $other->hand_optimized_type_constraint;
185 return unless $self->constraint == $other->constraint;
187 if ( $self->has_parent ) {
188 return unless $other->has_parent;
189 return unless $self->parent->equals( $other->parent );
191 return if $other->has_parent;
198 my ($self, $type_or_name) = @_;
200 my $type = Moose::Util::TypeConstraints::find_type_constraint($type_or_name) or return;
202 ($self->equals($type) || $self->is_subtype_of($type));
206 my ($self, $type_or_name) = @_;
208 my $type = Moose::Util::TypeConstraints::find_type_constraint($type_or_name) or return;
212 while (my $parent = $current->parent) {
213 return 1 if $parent->equals($type);
220 ## compiling the type constraint
222 sub compile_type_constraint {
224 $self->_compiled_type_constraint($self->_actually_compile_type_constraint);
227 ## type compilers ...
229 sub _actually_compile_type_constraint {
232 return $self->_compile_hand_optimized_type_constraint
233 if $self->has_hand_optimized_type_constraint;
235 my $check = $self->constraint;
236 unless ( defined $check ) {
238 Moose->throw_error( "Could not compile type constraint '"
240 . "' because no constraint check" );
243 return $self->_compile_subtype($check)
244 if $self->has_parent;
246 return $self->_compile_type($check);
249 sub _compile_hand_optimized_type_constraint {
252 my $type_constraint = $self->hand_optimized_type_constraint;
254 unless ( ref $type_constraint ) {
256 Moose->throw_error("Hand optimized type constraint is not a code reference");
259 return $type_constraint;
262 sub _compile_subtype {
263 my ($self, $check) = @_;
265 # gather all the parent constraintss in order
267 my $optimized_parent;
268 foreach my $parent ($self->_collect_all_parents) {
269 # if a parent is optimized, the optimized constraint already includes
270 # all of its parents tcs, so we can break the loop
271 if ($parent->has_hand_optimized_type_constraint) {
272 push @parents => $optimized_parent = $parent->hand_optimized_type_constraint;
276 push @parents => $parent->constraint;
280 @parents = grep { $_ != $null_constraint } reverse @parents;
282 unless ( @parents ) {
283 return $self->_compile_type($check);
284 } elsif( $optimized_parent and @parents == 1 ) {
285 # the case of just one optimized parent is optimized to prevent
286 # looping and the unnecessary localization
287 if ( $check == $null_constraint ) {
288 return $optimized_parent;
290 return subname($self->name, sub {
291 return undef unless $optimized_parent->($_[0]);
298 # general case, check all the constraints, from the first parent to ourselves
299 my @checks = @parents;
300 push @checks, $check if $check != $null_constraint;
301 return subname($self->name => sub {
304 foreach my $check (@checks) {
305 return undef unless $check->(@args);
313 my ($self, $check) = @_;
315 return $check if $check == $null_constraint; # Item, Any
317 return subname($self->name => sub {
326 sub _collect_all_parents {
329 my $current = $self->parent;
330 while (defined $current) {
331 push @parents => $current;
332 $current = $current->parent;
337 sub create_child_type {
338 my ($self, %opts) = @_;
339 my $class = ref $self;
340 return $class->new(%opts, parent => $self);
345 # ABSTRACT: The Moose Type Constraint metaclass
353 This class represents a single type constraint. Moose's built-in type
354 constraints, as well as constraints you define, are all stored in a
355 L<Moose::Meta::TypeConstraint::Registry> object as objects of this
360 C<Moose::Meta::TypeConstraint> is a subclass of L<Class::MOP::Object>.
366 =item B<< Moose::Meta::TypeConstraint->new(%options) >>
368 This creates a new type constraint based on the provided C<%options>:
374 The constraint name. If a name is not provided, it will be set to
379 A C<Moose::Meta::TypeConstraint> object which is the parent type for
380 the type being created. This is optional.
384 This is the subroutine reference that implements the actual constraint
385 check. This defaults to a subroutine which always returns true.
389 A subroutine reference which is used to generate an error message when
390 the constraint fails. This is optional.
394 A L<Moose::Meta::TypeCoercion> object representing the coercions to
395 the type. This is optional.
399 This is a variant of the C<constraint> parameter that is somehow
400 optimized. Typically, this means incorporating both the type's
401 constraint and all of its parents' constraints into a single
402 subroutine reference.
406 =item B<< $constraint->equals($type_name_or_object) >>
408 Returns true if the supplied name or type object is the same as the
411 =item B<< $constraint->is_subtype_of($type_name_or_object) >>
413 Returns true if the supplied name or type object is a parent of the
416 =item B<< $constraint->is_a_type_of($type_name_or_object) >>
418 Returns true if the given type is the same as the current type, or is
419 a parent of the current type. This is a shortcut for checking
420 C<equals> and C<is_subtype_of>.
422 =item B<< $constraint->coerce($value) >>
424 This will attempt to coerce the value to the type. If the type does not
425 have any defined coercions this will throw an error.
427 If no coercion can produce a value matching C<$constraint>, the original
430 =item B<< $constraint->assert_coerce($value) >>
432 This method behaves just like C<coerce>, but if the result is not valid
433 according to C<$constraint>, an error is thrown.
435 =item B<< $constraint->check($value) >>
437 Returns true if the given value passes the constraint for the type.
439 =item B<< $constraint->validate($value) >>
441 This is similar to C<check>. However, if the type I<is valid> then the
442 method returns an explicit C<undef>. If the type is not valid, we call
443 C<< $self->get_message($value) >> internally to generate an error
446 =item B<< $constraint->assert_valid($value) >>
448 Like C<check> and C<validate>, this method checks whether C<$value> is
449 valid under the constraint. If it is, it will return true. If it is not,
450 an exception will be thrown with the results of
451 C<< $self->get_message($value) >>.
453 =item B<< $constraint->name >>
455 Returns the type's name, as provided to the constructor.
457 =item B<< $constraint->parent >>
459 Returns the type's parent, as provided to the constructor, if any.
461 =item B<< $constraint->has_parent >>
463 Returns true if the type has a parent type.
465 =item B<< $constraint->parents >>
467 A synonym for C<parent>. This is useful for polymorphism with types
468 that can have more than one parent.
470 =item B<< $constraint->constraint >>
472 Returns the type's constraint, as provided to the constructor.
474 =item B<< $constraint->get_message($value) >>
476 This generates a method for the given value. If the type does not have
477 an explicit message, we generate a default message.
479 =item B<< $constraint->has_message >>
481 Returns true if the type has a message.
483 =item B<< $constraint->message >>
485 Returns the type's message as a subroutine reference.
487 =item B<< $constraint->coercion >>
489 Returns the type's L<Moose::Meta::TypeCoercion> object, if one
492 =item B<< $constraint->has_coercion >>
494 Returns true if the type has a coercion.
496 =item B<< $constraint->hand_optimized_type_constraint >>
498 Returns the type's hand optimized constraint, as provided to the
499 constructor via the C<optimized> option.
501 =item B<< $constraint->has_hand_optimized_type_constraint >>
503 Returns true if the type has an optimized constraint.
505 =item B<< $constraint->create_child_type(%options) >>
507 This returns a new type constraint of the same class using the
508 provided C<%options>. The C<parent> option will be the current type.
510 This method exists so that subclasses of this class can override this
511 behavior and change how child types are created.
517 See L<Moose/BUGS> for details on reporting bugs.