1 package Mouse::Util::TypeConstraints;
2 use Mouse::Util; # enables strict and warnings
4 use Mouse::Meta::TypeConstraint;
10 Mouse::Exporter->setup_import_methods(
12 as where message optimize_as
15 type subtype class_type role_type duck_type
20 register_type_constraint
24 our @CARP_NOT = qw(Mouse::Meta::Attribute);
29 $TYPE{Any} = Mouse::Meta::TypeConstraint->new(
34 # $name => $parent, $code,
40 Maybe => 'Item', undef,
43 Undef => 'Item', \&Undef,
44 Defined => 'Item', \&Defined,
45 Bool => 'Item', \&Bool,
46 Value => 'Defined', \&Value,
47 Str => 'Value', \&Str,
52 Ref => 'Defined', \&Ref,
53 ScalarRef => 'Ref', \&ScalarRef,
54 ArrayRef => 'Ref', \&ArrayRef,
55 HashRef => 'Ref', \&HashRef,
56 CodeRef => 'Ref', \&CodeRef,
57 RegexpRef => 'Ref', \&RegexpRef,
58 GlobRef => 'Ref', \&GlobRef,
61 FileHandle => 'GlobRef', \&FileHandle,
62 Object => 'Ref', \&Object,
64 # special string types
65 ClassName => 'Str', \&ClassName,
66 RoleName => 'ClassName', \&RoleName,
69 while (my ($name, $parent, $code) = splice @builtins, 0, 3) {
70 $TYPE{$name} = Mouse::Meta::TypeConstraint->new(
72 parent => $TYPE{$parent},
77 # parametarizable types
78 $TYPE{Maybe} {constraint_generator} = \&_parameterize_Maybe_for;
79 $TYPE{ArrayRef}{constraint_generator} = \&_parameterize_ArrayRef_for;
80 $TYPE{HashRef} {constraint_generator} = \&_parameterize_HashRef_for;
83 sub as ($) { (as => $_[0]) } ## no critic
84 sub where (&) { (where => $_[0]) } ## no critic
85 sub message (&) { (message => $_[0]) } ## no critic
86 sub optimize_as (&) { (optimize_as => $_[0]) } ## no critic
89 sub via (&) { $_[0] } ## no critic
93 sub optimized_constraints { # DEPRECATED
94 Carp::cluck('optimized_constraints() has been deprecated');
98 undef @builtins; # free the allocated memory
99 @builtins = keys %TYPE; # reuse it
100 sub list_all_builtin_type_constraints { @builtins }
101 sub list_all_type_constraints { keys %TYPE }
104 my $is_subtype = shift;
108 if(@_ == 1 && ref $_[0] ){ # @_ : { name => $name, where => ... }
111 elsif(@_ == 2 && ref $_[1]) { # @_ : $name => { where => ... }
115 elsif(@_ % 2) { # @_ : $name => ( where => ... )
118 else{ # @_ : (name => $name, where => ...)
128 my $parent = delete $args{as};
129 if($is_subtype && !$parent){
130 $parent = delete $args{name};
134 if(defined $parent) {
135 $args{parent} = find_or_create_isa_type_constraint($parent);
139 # set 'package_defined_in' only if it is not a core package
140 my $this = $args{package_defined_in};
143 if($this !~ /\A Mouse \b/xms){
144 $args{package_defined_in} = $this;
148 if(defined $TYPE{$name}){
149 my $that = $TYPE{$name}->{package_defined_in} || __PACKAGE__;
152 if($that eq __PACKAGE__) {
153 $note = sprintf " ('%s' is %s type constraint)",
155 scalar(grep { $name eq $_ } list_all_builtin_type_constraints())
157 : 'an implicitly created';
159 Carp::croak("The type constraint '$name' has already been created in $that"
160 . " and cannot be created again in $this" . $note);
165 $args{constraint} = delete $args{where} if exists $args{where};
166 $args{optimized} = delete $args{optimized_as} if exists $args{optimized_as};
168 my $constraint = Mouse::Meta::TypeConstraint->new(%args);
171 return $TYPE{$name} = $constraint;
179 return _define_type 0, @_;
183 return _define_type 1, @_;
186 sub coerce { # coerce $type, from $from, via { ... }, ...
187 my $type_name = shift;
188 my $type = find_type_constraint($type_name)
189 or Carp::croak("Cannot find type '$type_name', perhaps you forgot to load it");
191 $type->_add_type_coercions(@_);
196 my($name, $options) = @_;
197 my $class = $options->{class} || $name;
200 return subtype $name => (
202 optimized_as => Mouse::Util::generate_isa_predicate_for($class),
208 my($name, $options) = @_;
209 my $role = $options->{role} || $name;
212 return subtype $name => (
214 optimized_as => sub {
215 return Scalar::Util::blessed($_[0])
216 && Mouse::Util::does_role($_[0], $role);
225 if(ref($_[0]) ne 'ARRAY'){
229 @methods = (@_ == 1 && ref($_[0]) eq 'ARRAY') ? @{$_[0]} : @_;
232 return _define_type 1, $name => (
234 optimized_as => Mouse::Util::generate_can_predicate_for(\@methods),
237 my @missing = grep { !$object->can($_) } @methods;
239 . ' is missing methods '
240 . Mouse::Util::quoted_english_list(@missing);
242 methods => \@methods,
249 if(!(@_ == 1 && ref($_[0]) eq 'ARRAY')){
253 %valid = map{ $_ => undef }
254 (@_ == 1 && ref($_[0]) eq 'ARRAY' ? @{$_[0]} : @_);
257 return _define_type 1, $name => (
260 return defined($_[0]) && !ref($_[0]) && exists $valid{$_[0]};
265 sub _find_or_create_regular_type{
266 my($spec, $create) = @_;
268 return $TYPE{$spec} if exists $TYPE{$spec};
270 my $meta = Mouse::Util::get_metaclass_by_name($spec);
273 return $create ? class_type($spec) : undef;
276 if(Mouse::Util::is_a_metarole($meta)){
277 return role_type($spec);
280 return class_type($spec);
284 sub _find_or_create_parameterized_type{
285 my($base, $param) = @_;
287 my $name = sprintf '%s[%s]', $base->name, $param->name;
289 $TYPE{$name} ||= $base->parameterize($param, $name);
292 sub _find_or_create_union_type{
293 return if grep{ not defined } @_;
294 my @types = sort map{ $_->{type_constraints} ? @{$_->{type_constraints}} : $_ } @_;
296 my $name = join '|', @types;
299 $TYPE{$name} ||= Mouse::Meta::TypeConstraint->new(
301 type_constraints => \@types,
307 # param : '[' type ']' | NOTHING
311 if($c->{spec} =~ s/^\[//){
312 my $type = _parse_type($c, 1);
314 if($c->{spec} =~ s/^\]//){
317 Carp::croak("Syntax error in type: missing right square bracket in '$c->{orig}'");
325 my($c, $create) = @_;
327 if($c->{spec} =~ s/\A ([\w.:]+) //xms){
328 return _find_or_create_regular_type($1, $create);
330 Carp::croak("Syntax error in type: expect type name near '$c->{spec}' in '$c->{orig}'");
333 # single_type : name param
334 sub _parse_single_type {
335 my($c, $create) = @_;
337 my $type = _parse_name($c, $create);
338 my $param = _parse_param($c);
342 return _find_or_create_parameterized_type($type, $param);
348 elsif(defined $param){
349 Carp::croak("Undefined type with parameter [$param] in '$c->{orig}'");
356 # type : single_type ('|' single_type)*
358 my($c, $create) = @_;
360 my $type = _parse_single_type($c, $create);
361 if($c->{spec}){ # can be an union type
363 while($c->{spec} =~ s/^\|//){
364 push @types, _parse_single_type($c, $create);
367 return _find_or_create_union_type($type, @types);
374 sub find_type_constraint {
376 return $spec if Mouse::Util::is_a_type_constraint($spec) or not defined $spec;
382 sub register_type_constraint {
383 my($constraint) = @_;
384 Carp::croak("No type supplied / type is not a valid type constraint")
385 unless Mouse::Util::is_a_type_constraint($constraint);
386 return $TYPE{$constraint->name} = $constraint;
389 sub find_or_parse_type_constraint {
391 return $spec if Mouse::Util::is_a_type_constraint($spec) or not defined $spec;
393 $spec =~ tr/ \t\r\n//d;
395 my $tc = $TYPE{$spec};
404 $tc = _parse_type(\%context);
407 Carp::croak("Syntax error: extra elements '$context{spec}' in '$context{orig}'");
410 return $TYPE{$spec} = $tc;
413 sub find_or_create_does_type_constraint{
414 # XXX: Moose does not register a new role_type, but Mouse does.
415 my $tc = find_or_parse_type_constraint(@_);
416 return defined($tc) ? $tc : role_type(@_);
419 sub find_or_create_isa_type_constraint {
420 # XXX: Moose does not register a new class_type, but Mouse does.
421 my $tc = find_or_parse_type_constraint(@_);
422 return defined($tc) ? $tc : class_type(@_);
430 Mouse::Util::TypeConstraints - Type constraint system for Mouse
434 This document describes Mouse version 0.84
438 use Mouse::Util::TypeConstraints;
444 subtype 'NaturalLessThanTen'
447 => message { "This number ($_) is not less than ten!" };
453 enum 'RGBColors' => qw(red green blue);
455 no Mouse::Util::TypeConstraints;
459 This module provides Mouse with the ability to create custom type
460 constraints to be used in attribute definition.
462 =head2 Important Caveat
464 This is B<NOT> a type system for Perl 5. These are type constraints,
465 and they are not used by Mouse unless you tell it to. No type
466 inference is performed, expressions are not typed, etc. etc. etc.
468 A type constraint is at heart a small "check if a value is valid"
469 function. A constraint can be associated with an attribute. This
470 simplifies parameter validation, and makes your code clearer to read,
471 because you can refer to constraints by name.
473 =head2 Slightly Less Important Caveat
475 It is B<always> a good idea to quote your type names.
477 This prevents Perl from trying to execute the call as an indirect
478 object call. This can be an issue when you have a subtype with the
479 same name as a valid class.
483 subtype DateTime => as Object => where { $_->isa('DateTime') };
485 will I<just work>, while this:
488 subtype DateTime => as Object => where { $_->isa('DateTime') };
490 will fail silently and cause many headaches. The simple way to solve
491 this, as well as future proof your subtypes from classes which have
492 yet to have been created, is to quote the type name:
495 subtype 'DateTime' => as 'Object' => where { $_->isa('DateTime') };
497 =head2 Default Type Constraints
499 This module also provides a simple hierarchy for Perl 5 types, here is
500 that hierarchy represented visually.
524 B<NOTE:> Any type followed by a type parameter C<[`a]> can be
525 parameterized, this means you can say:
527 ArrayRef[Int] # an array of integers
528 HashRef[CodeRef] # a hash of str to CODE ref mappings
529 Maybe[Str] # value may be a string, may be undefined
531 If Mouse finds a name in brackets that it does not recognize as an
532 existing type, it assumes that this is a class name, for example
533 C<ArrayRef[DateTime]>.
535 B<NOTE:> The C<Undef> type constraint for the most part works
536 correctly now, but edge cases may still exist, please use it
539 B<NOTE:> The C<ClassName> type constraint does a complex package
540 existence check. This means that your class B<must> be loaded for this
541 type constraint to pass.
543 B<NOTE:> The C<RoleName> constraint checks a string is a I<package
544 name> which is a role, like C<'MyApp::Role::Comparable'>. The C<Role>
545 constraint checks that an I<object does> the named role.
547 =head2 Type Constraint Naming
549 Type name declared via this module can only contain alphanumeric
550 characters, colons (:), and periods (.).
552 Since the types created by this module are global, it is suggested
553 that you namespace your types just as you would namespace your
554 modules. So instead of creating a I<Color> type for your
555 B<My::Graphics> module, you would call the type
556 I<My::Graphics::Types::Color> instead.
558 =head2 Use with Other Constraint Modules
560 This module can play nicely with other constraint modules with some
561 slight tweaking. The C<where> clause in types is expected to be a
562 C<CODE> reference which checks it's first argument and returns a
563 boolean. Since most constraint modules work in a similar way, it
564 should be simple to adapt them to work with Mouse.
566 For instance, this is how you could use it with
567 L<Declare::Constraints::Simple> to declare a completely new type.
569 type 'HashOfArrayOfObjects',
573 -values => IsArrayRef(IsObject)
577 Here is an example of using L<Test::Deep> and it's non-test
578 related C<eq_deeply> function.
580 type 'ArrayOfHashOfBarsAndRandomNumbers'
583 array_each(subhashof({
585 random_number => ignore()
591 =head2 C<< list_all_builtin_type_constraints -> (Names) >>
593 Returns the names of builtin type constraints.
595 =head2 C<< list_all_type_constraints -> (Names) >>
597 Returns the names of all the type constraints.
603 =item C<< type $name => where { } ... -> Mouse::Meta::TypeConstraint >>
605 =item C<< subtype $name => as $parent => where { } ... -> Mouse::Meta::TypeConstraint >>
607 =item C<< subtype as $parent => where { } ... -> Mouse::Meta::TypeConstraint >>
609 =item C<< class_type ($class, ?$options) -> Mouse::Meta::TypeConstraint >>
611 =item C<< role_type ($role, ?$options) -> Mouse::Meta::TypeConstraint >>
613 =item C<< duck_type($name, @methods | \@methods) -> Mouse::Meta::TypeConstraint >>
615 =item C<< duck_type(\@methods) -> Mouse::Meta::TypeConstraint >>
617 =item C<< enum($name, @values | \@values) -> Mouse::Meta::TypeConstraint >>
619 =item C<< enum (\@values) -> Mouse::Meta::TypeConstraint >>
621 =item C<< coerce $type => from $another_type, via { }, ... >>
627 =item C<< find_type_constraint(Type) -> Mouse::Meta::TypeConstraint >>
633 Much of this documentation was taken from C<Moose::Util::TypeConstraints>
637 L<Moose::Util::TypeConstraints>