2 package Moose::Util::TypeConstraints;
8 use List::MoreUtils qw( all any );
9 use Scalar::Util qw( blessed reftype );
12 our $VERSION = '0.73';
13 $VERSION = eval $VERSION;
14 our $AUTHORITY = 'cpan:STEVAN';
16 ## --------------------------------------------------------
17 # Prototyped subs must be predeclared because we have a
18 # circular dependency with Moose::Meta::Attribute et. al.
19 # so in case of us being use'd first the predeclaration
20 # ensures the prototypes are in scope when consumers are
29 ## --------------------------------------------------------
31 use Moose::Meta::TypeConstraint;
32 use Moose::Meta::TypeConstraint::Union;
33 use Moose::Meta::TypeConstraint::Parameterized;
34 use Moose::Meta::TypeConstraint::Parameterizable;
35 use Moose::Meta::TypeConstraint::Class;
36 use Moose::Meta::TypeConstraint::Role;
37 use Moose::Meta::TypeConstraint::Enum;
38 use Moose::Meta::TypeCoercion;
39 use Moose::Meta::TypeCoercion::Union;
40 use Moose::Meta::TypeConstraint::Registry;
41 use Moose::Util::TypeConstraints::OptimizedConstraints;
43 Moose::Exporter->setup_import_methods(
46 type subtype class_type role_type maybe_type duck_type
47 as where message optimize_as
51 register_type_constraint )
56 ## --------------------------------------------------------
57 ## type registry and some useful functions for it
58 ## --------------------------------------------------------
60 my $REGISTRY = Moose::Meta::TypeConstraint::Registry->new;
62 sub get_type_constraint_registry {$REGISTRY}
63 sub list_all_type_constraints { keys %{ $REGISTRY->type_constraints } }
65 sub export_type_constraints_as_functions {
68 foreach my $constraint ( keys %{ $REGISTRY->type_constraints } ) {
69 my $tc = $REGISTRY->get_type_constraint($constraint)
70 ->_compiled_type_constraint;
71 *{"${pkg}::${constraint}"}
72 = sub { $tc->( $_[0] ) ? 1 : undef }; # the undef is for compat
76 sub create_type_constraint_union {
77 my @type_constraint_names;
79 if ( scalar @_ == 1 && _detect_type_constraint_union( $_[0] ) ) {
80 @type_constraint_names = _parse_type_constraint_union( $_[0] );
83 @type_constraint_names = @_;
86 ( scalar @type_constraint_names >= 2 )
87 || __PACKAGE__->_throw_error(
88 "You must pass in at least 2 type names to make a union");
90 my @type_constraints = map {
91 find_or_parse_type_constraint($_)
92 || __PACKAGE__->_throw_error(
93 "Could not locate type constraint ($_) for the union");
94 } @type_constraint_names;
96 return Moose::Meta::TypeConstraint::Union->new(
97 type_constraints => \@type_constraints );
100 sub create_parameterized_type_constraint {
101 my $type_constraint_name = shift;
102 my ( $base_type, $type_parameter )
103 = _parse_parameterized_type_constraint($type_constraint_name);
105 ( defined $base_type && defined $type_parameter )
106 || __PACKAGE__->_throw_error(
107 "Could not parse type name ($type_constraint_name) correctly");
109 if ( $REGISTRY->has_type_constraint($base_type) ) {
110 my $base_type_tc = $REGISTRY->get_type_constraint($base_type);
111 return _create_parameterized_type_constraint(
117 __PACKAGE__->_throw_error(
118 "Could not locate the base type ($base_type)");
122 sub _create_parameterized_type_constraint {
123 my ( $base_type_tc, $type_parameter ) = @_;
124 if ( $base_type_tc->can('parameterize') ) {
125 return $base_type_tc->parameterize($type_parameter);
128 return Moose::Meta::TypeConstraint::Parameterized->new(
129 name => $base_type_tc->name . '[' . $type_parameter . ']',
130 parent => $base_type_tc,
132 find_or_create_isa_type_constraint($type_parameter),
137 #should we also support optimized checks?
138 sub create_class_type_constraint {
139 my ( $class, $options ) = @_;
141 # too early for this check
142 #find_type_constraint("ClassName")->check($class)
143 # || __PACKAGE__->_throw_error("Can't create a class type constraint because '$class' is not a class name");
151 $options{name} ||= "__ANON__";
153 Moose::Meta::TypeConstraint::Class->new(%options);
156 sub create_role_type_constraint {
157 my ( $role, $options ) = @_;
159 # too early for this check
160 #find_type_constraint("ClassName")->check($class)
161 # || __PACKAGE__->_throw_error("Can't create a class type constraint because '$class' is not a class name");
169 $options{name} ||= "__ANON__";
171 Moose::Meta::TypeConstraint::Role->new(%options);
174 sub find_or_create_type_constraint {
175 my ( $type_constraint_name, $options_for_anon_type ) = @_;
178 = find_or_parse_type_constraint($type_constraint_name) ) {
181 elsif ( defined $options_for_anon_type ) {
184 # if there is no $options_for_anon_type
185 # specified, then we assume they don't
186 # want to create one, and return nothing.
188 # otherwise assume that we should create
189 # an ANON type with the $options_for_anon_type
190 # options which can be passed in. It should
191 # be noted that these don't get registered
192 # so we need to return it.
194 return Moose::Meta::TypeConstraint->new(
196 %{$options_for_anon_type}
203 sub find_or_create_isa_type_constraint {
204 my $type_constraint_name = shift;
205 find_or_parse_type_constraint($type_constraint_name)
206 || create_class_type_constraint($type_constraint_name);
209 sub find_or_create_does_type_constraint {
210 my $type_constraint_name = shift;
211 find_or_parse_type_constraint($type_constraint_name)
212 || create_role_type_constraint($type_constraint_name);
215 sub find_or_parse_type_constraint {
216 my $type_constraint_name = normalize_type_constraint_name(shift);
219 if ( $constraint = find_type_constraint($type_constraint_name) ) {
222 elsif ( _detect_type_constraint_union($type_constraint_name) ) {
223 $constraint = create_type_constraint_union($type_constraint_name);
225 elsif ( _detect_parameterized_type_constraint($type_constraint_name) ) {
227 = create_parameterized_type_constraint($type_constraint_name);
233 $REGISTRY->add_type_constraint($constraint);
237 sub normalize_type_constraint_name {
238 my $type_constraint_name = shift;
239 $type_constraint_name =~ s/\s//g;
240 return $type_constraint_name;
246 local $Carp::CarpLevel = $Carp::CarpLevel + 1;
247 Carp::confess($error);
250 ## --------------------------------------------------------
251 ## exported functions ...
252 ## --------------------------------------------------------
254 sub find_type_constraint {
257 if ( blessed $type and $type->isa("Moose::Meta::TypeConstraint") ) {
261 return unless $REGISTRY->has_type_constraint($type);
262 return $REGISTRY->get_type_constraint($type);
266 sub register_type_constraint {
267 my $constraint = shift;
268 __PACKAGE__->_throw_error("can't register an unnamed type constraint")
269 unless defined $constraint->name;
270 $REGISTRY->add_type_constraint($constraint);
278 # back-compat version, called without sugar
279 if ( !any { ( reftype($_) || '' ) eq 'HASH' } @_ ) {
280 return _create_type_constraint( $_[0], undef, $_[1] );
285 my %p = map { %{$_} } @_;
287 return _create_type_constraint(
288 $name, undef, $p{where}, $p{message},
295 # crazy back-compat code for being called without sugar ...
297 # subtype 'Parent', sub { where };
298 if ( scalar @_ == 2 && ( reftype( $_[1] ) || '' ) eq 'CODE' ) {
299 return _create_type_constraint( undef, @_ );
302 # subtype 'Parent', sub { where }, sub { message };
303 # subtype 'Parent', sub { where }, sub { message }, sub { optimized };
304 if ( scalar @_ >= 3 && all { ( reftype($_) || '' ) eq 'CODE' }
306 return _create_type_constraint( undef, @_ );
309 # subtype 'Name', 'Parent', ...
310 if ( scalar @_ >= 2 && all { !ref } @_[ 0, 1 ] ) {
311 return _create_type_constraint(@_);
314 if ( @_ == 1 && !ref $_[0] ) {
315 __PACKAGE__->_throw_error(
316 'A subtype cannot consist solely of a name, it must have a parent'
320 # The blessed check is mostly to accommodate MooseX::Types, which
321 # uses an object which overloads stringification as a type name.
322 my $name = ref $_[0] && !blessed $_[0] ? undef : shift;
324 my %p = map { %{$_} } @_;
326 # subtype Str => where { ... };
327 if ( !exists $p{as} ) {
332 return _create_type_constraint(
333 $name, $p{as}, $p{where}, $p{message},
339 register_type_constraint(
340 create_class_type_constraint(
342 ( defined( $_[1] ) ? $_[1] : () ),
347 sub role_type ($;$) {
348 register_type_constraint(
349 create_role_type_constraint(
351 ( defined( $_[1] ) ? $_[1] : () ),
357 my ($type_parameter) = @_;
359 register_type_constraint(
360 $REGISTRY->get_type_constraint('Maybe')->parameterize($type_parameter)
365 my ( $type_name, @methods ) = @_;
366 if ( ref $type_name eq 'ARRAY' && !@methods ) {
367 @methods = @$type_name;
371 register_type_constraint(
372 _create_type_constraint(
377 for (@methods) { return 0 unless $obj->can($_) }
382 my @missing_methods = grep { !$obj->can($_) } @methods;
384 "${\blessed($obj)} is missing methods '@missing_methods'";
391 my ( $type_name, @coercion_map ) = @_;
392 _install_type_coercions( $type_name, \@coercion_map );
395 # The trick of returning @_ lets us avoid having to specify a
396 # prototype. Perl will parse this:
404 # subtype( 'Foo', as( 'Str', where { ... } ) );
406 # If as() returns all it's extra arguments, this just works, and
407 # preserves backwards compatibility.
408 sub as { { as => shift }, @_ }
409 sub where (&) { { where => $_[0] } }
410 sub message (&) { { message => $_[0] } }
411 sub optimize_as (&) { { optimize_as => $_[0] } }
414 sub via (&) { $_[0] }
417 my ( $type_name, @values ) = @_;
420 # if only an array-ref is passed then
421 # you get an anon-enum
423 if ( ref $type_name eq 'ARRAY' && !@values ) {
424 @values = @$type_name;
427 ( scalar @values >= 2 )
428 || __PACKAGE__->_throw_error(
429 "You must have at least two values to enumerate through");
430 my %valid = map { $_ => 1 } @values;
432 register_type_constraint(
433 create_enum_type_constraint(
440 sub create_enum_type_constraint {
441 my ( $type_name, $values ) = @_;
443 Moose::Meta::TypeConstraint::Enum->new(
444 name => $type_name || '__ANON__',
449 ## --------------------------------------------------------
450 ## desugaring functions ...
451 ## --------------------------------------------------------
453 sub _create_type_constraint ($$$;$$) {
458 my $optimized = shift;
460 my $pkg_defined_in = scalar( caller(1) );
462 if ( defined $name ) {
463 my $type = $REGISTRY->get_type_constraint($name);
465 ( $type->_package_defined_in eq $pkg_defined_in )
467 "The type constraint '$name' has already been created in "
468 . $type->_package_defined_in
469 . " and cannot be created again in "
473 $name =~ /^[\w:\.]+$/
474 or die qq{$name contains invalid characters for a type name.}
475 . qq{ Names can contain alphanumeric character, ":", and "."\n};
480 package_defined_in => $pkg_defined_in,
482 ( $check ? ( constraint => $check ) : () ),
483 ( $message ? ( message => $message ) : () ),
484 ( $optimized ? ( optimized => $optimized ) : () ),
493 : find_or_create_isa_type_constraint($parent)
495 $constraint = $parent->create_child_type(%opts);
498 $constraint = Moose::Meta::TypeConstraint->new(%opts);
501 $REGISTRY->add_type_constraint($constraint)
507 sub _install_type_coercions ($$) {
508 my ( $type_name, $coercion_map ) = @_;
509 my $type = find_type_constraint($type_name);
511 || __PACKAGE__->_throw_error(
512 "Cannot find type '$type_name', perhaps you forgot to load it.");
513 if ( $type->has_coercion ) {
514 $type->coercion->add_type_coercions(@$coercion_map);
517 my $type_coercion = Moose::Meta::TypeCoercion->new(
518 type_coercion_map => $coercion_map,
519 type_constraint => $type
521 $type->coercion($type_coercion);
525 ## --------------------------------------------------------
526 ## type notation parsing ...
527 ## --------------------------------------------------------
531 # All I have to say is mugwump++ cause I know
532 # do not even have enough regexp-fu to be able
533 # to have written this (I can only barely
534 # understand it as it is)
539 my $valid_chars = qr{[\w:\.]};
540 my $type_atom = qr{ $valid_chars+ };
544 my $type = qr{ $valid_chars+ (?: \[ \s* (??{$any}) \s* \] )? }x;
545 my $type_capture_parts
546 = qr{ ($valid_chars+) (?: \[ \s* ((??{$any})) \s* \] )? }x;
547 my $type_with_parameter
548 = qr{ $valid_chars+ \[ \s* (??{$any}) \s* \] }x;
550 my $op_union = qr{ \s* \| \s* }x;
551 my $union = qr{ $type (?: $op_union $type )+ }x;
553 $any = qr{ $type | $union }x;
555 sub _parse_parameterized_type_constraint {
556 { no warnings 'void'; $any; } # force capture of interpolated lexical
557 $_[0] =~ m{ $type_capture_parts }x;
561 sub _detect_parameterized_type_constraint {
562 { no warnings 'void'; $any; } # force capture of interpolated lexical
563 $_[0] =~ m{ ^ $type_with_parameter $ }x;
566 sub _parse_type_constraint_union {
567 { no warnings 'void'; $any; } # force capture of interpolated lexical
570 while ( $given =~ m{ \G (?: $op_union )? ($type) }gcx ) {
573 ( pos($given) eq length($given) )
574 || __PACKAGE__->_throw_error( "'$given' didn't parse (parse-pos="
582 sub _detect_type_constraint_union {
583 { no warnings 'void'; $any; } # force capture of interpolated lexical
584 $_[0] =~ m{^ $type $op_union $type ( $op_union .* )? $}x;
588 ## --------------------------------------------------------
589 # define some basic built-in types
590 ## --------------------------------------------------------
592 # By making these classes immutable before creating all the types we
593 # below, we avoid repeatedly calling the slow MOP-based accessors.
595 inline_constructor => 1,
596 constructor_name => "_new",
598 # these are Class::MOP accessors, so they need inlining
599 inline_accessors => 1
600 ) for grep { $_->is_mutable }
603 Moose::Meta::TypeConstraint
604 Moose::Meta::TypeConstraint::Union
605 Moose::Meta::TypeConstraint::Parameterized
606 Moose::Meta::TypeConstraint::Parameterizable
607 Moose::Meta::TypeConstraint::Class
608 Moose::Meta::TypeConstraint::Role
609 Moose::Meta::TypeConstraint::Enum
610 Moose::Meta::TypeConstraint::Registry
613 type 'Any' => where {1}; # meta-type including all
614 type 'Item' => where {1}; # base-type
616 subtype 'Undef' => as 'Item' => where { !defined($_) };
617 subtype 'Defined' => as 'Item' => where { defined($_) };
619 subtype 'Bool' => as 'Item' =>
620 where { !defined($_) || $_ eq "" || "$_" eq '1' || "$_" eq '0' };
622 subtype 'Value' => as 'Defined' => where { !ref($_) } =>
623 optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::Value;
625 subtype 'Ref' => as 'Defined' => where { ref($_) } =>
626 optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::Ref;
628 subtype 'Str' => as 'Value' => where {1} =>
629 optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::Str;
631 subtype 'Num' => as 'Value' =>
632 where { Scalar::Util::looks_like_number($_) } =>
633 optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::Num;
635 subtype 'Int' => as 'Num' => where { "$_" =~ /^-?[0-9]+$/ } =>
636 optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::Int;
638 subtype 'ScalarRef' => as 'Ref' => where { ref($_) eq 'SCALAR' } =>
640 \&Moose::Util::TypeConstraints::OptimizedConstraints::ScalarRef;
641 subtype 'CodeRef' => as 'Ref' => where { ref($_) eq 'CODE' } =>
642 optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::CodeRef;
643 subtype 'RegexpRef' => as 'Ref' => where { ref($_) eq 'Regexp' } =>
645 \&Moose::Util::TypeConstraints::OptimizedConstraints::RegexpRef;
646 subtype 'GlobRef' => as 'Ref' => where { ref($_) eq 'GLOB' } =>
647 optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::GlobRef;
650 # scalar filehandles are GLOB refs,
651 # but a GLOB ref is not always a filehandle
652 subtype 'FileHandle' => as 'GlobRef' => where {
653 Scalar::Util::openhandle($_) || ( blessed($_) && $_->isa("IO::Handle") );
655 \&Moose::Util::TypeConstraints::OptimizedConstraints::FileHandle;
658 # blessed(qr/.../) returns true,.. how odd
659 subtype 'Object' => as 'Ref' =>
660 where { blessed($_) && blessed($_) ne 'Regexp' } =>
661 optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::Object;
663 subtype 'Role' => as 'Object' => where { $_->can('does') } =>
664 optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::Role;
666 my $_class_name_checker = sub { };
668 subtype 'ClassName' => as 'Str' =>
669 where { Class::MOP::is_class_loaded($_) } => optimize_as
670 \&Moose::Util::TypeConstraints::OptimizedConstraints::ClassName;
672 subtype 'RoleName' => as 'ClassName' => where {
673 ( ( $_->can('meta') || return )->($_) || return )
674 ->isa('Moose::Meta::Role');
676 \&Moose::Util::TypeConstraints::OptimizedConstraints::RoleName;
678 ## --------------------------------------------------------
679 # parameterizable types ...
681 $REGISTRY->add_type_constraint(
682 Moose::Meta::TypeConstraint::Parameterizable->new(
684 package_defined_in => __PACKAGE__,
685 parent => find_type_constraint('Ref'),
686 constraint => sub { ref($_) eq 'ARRAY' },
688 \&Moose::Util::TypeConstraints::OptimizedConstraints::ArrayRef,
689 constraint_generator => sub {
690 my $type_parameter = shift;
691 my $check = $type_parameter->_compiled_type_constraint;
693 foreach my $x (@$_) {
694 ( $check->($x) ) || return;
702 $REGISTRY->add_type_constraint(
703 Moose::Meta::TypeConstraint::Parameterizable->new(
705 package_defined_in => __PACKAGE__,
706 parent => find_type_constraint('Ref'),
707 constraint => sub { ref($_) eq 'HASH' },
709 \&Moose::Util::TypeConstraints::OptimizedConstraints::HashRef,
710 constraint_generator => sub {
711 my $type_parameter = shift;
712 my $check = $type_parameter->_compiled_type_constraint;
714 foreach my $x ( values %$_ ) {
715 ( $check->($x) ) || return;
723 $REGISTRY->add_type_constraint(
724 Moose::Meta::TypeConstraint::Parameterizable->new(
726 package_defined_in => __PACKAGE__,
727 parent => find_type_constraint('Item'),
728 constraint => sub {1},
729 constraint_generator => sub {
730 my $type_parameter = shift;
731 my $check = $type_parameter->_compiled_type_constraint;
733 return 1 if not( defined($_) ) || $check->($_);
740 my @PARAMETERIZABLE_TYPES
741 = map { $REGISTRY->get_type_constraint($_) } qw[ArrayRef HashRef Maybe];
743 sub get_all_parameterizable_types {@PARAMETERIZABLE_TYPES}
745 sub add_parameterizable_type {
748 && $type->isa('Moose::Meta::TypeConstraint::Parameterizable') )
749 || __PACKAGE__->_throw_error(
750 "Type must be a Moose::Meta::TypeConstraint::Parameterizable not $type"
752 push @PARAMETERIZABLE_TYPES => $type;
755 ## --------------------------------------------------------
756 # end of built-in types ...
757 ## --------------------------------------------------------
760 my @BUILTINS = list_all_type_constraints();
761 sub list_all_builtin_type_constraints {@BUILTINS}
768 goto &Moose::throw_error;
779 Moose::Util::TypeConstraints - Type constraint system for Moose
783 use Moose::Util::TypeConstraints;
789 subtype 'NaturalLessThanTen'
792 => message { "This number ($_) is not less than ten!" };
798 enum 'RGBColors' => qw(red green blue);
800 no Moose::Util::TypeConstraints;
804 This module provides Moose with the ability to create custom type
805 constraints to be used in attribute definition.
807 =head2 Important Caveat
809 This is B<NOT> a type system for Perl 5. These are type constraints,
810 and they are not used by Moose unless you tell it to. No type
811 inference is performed, expressions are not typed, etc. etc. etc.
813 A type constraint is at heart a small "check if a value is valid"
814 function. A constraint can be associated with an attribute. This
815 simplifies parameter validation, and makes your code clearer to read,
816 because you can refer to constraints by name.
818 =head2 Slightly Less Important Caveat
820 It is B<always> a good idea to quote your type names.
822 This prevents Perl from trying to execute the call as an indirect
823 object call. This can be an issue when you have a subtype with the
824 same name as a valid class.
828 subtype DateTime => as Object => where { $_->isa('DateTime') };
830 will I<just work>, while this:
833 subtype DateTime => as Object => where { $_->isa('DateTime') };
835 will fail silently and cause many headaches. The simple way to solve
836 this, as well as future proof your subtypes from classes which have
837 yet to have been created, is to quote the type name:
840 subtype 'DateTime' => as 'Object' => where { $_->isa('DateTime') };
842 =head2 Default Type Constraints
844 This module also provides a simple hierarchy for Perl 5 types, here is
845 that hierarchy represented visually.
870 B<NOTE:> Any type followed by a type parameter C<[`a]> can be
871 parameterized, this means you can say:
873 ArrayRef[Int] # an array of integers
874 HashRef[CodeRef] # a hash of str to CODE ref mappings
875 Maybe[Str] # value may be a string, may be undefined
877 If Moose finds a name in brackets that it does not recognize as an
878 existing type, it assumes that this is a class name, for example
879 C<ArrayRef[DateTime]>.
881 B<NOTE:> Unless you parameterize a type, then it is invalid to include
882 the square brackets. I.e. C<ArrayRef[]> will be treated as a new type
883 name, I<not> as a parameterization of C<ArrayRef>.
885 B<NOTE:> The C<Undef> type constraint for the most part works
886 correctly now, but edge cases may still exist, please use it
889 B<NOTE:> The C<ClassName> type constraint does a complex package
890 existence check. This means that your class B<must> be loaded for this
891 type constraint to pass.
893 B<NOTE:> The C<RoleName> constraint checks a string is a I<package
894 name> which is a role, like C<'MyApp::Role::Comparable'>. The C<Role>
895 constraint checks that an I<object does> the named role.
897 =head2 Type Constraint Naming
899 Type name declared via this module can only contain alphanumeric
900 characters, colons (:), and periods (.).
902 Since the types created by this module are global, it is suggested
903 that you namespace your types just as you would namespace your
904 modules. So instead of creating a I<Color> type for your
905 B<My::Graphics> module, you would call the type
906 I<My::Graphics::Types::Color> instead.
908 =head2 Use with Other Constraint Modules
910 This module can play nicely with other constraint modules with some
911 slight tweaking. The C<where> clause in types is expected to be a
912 C<CODE> reference which checks it's first argument and returns a
913 boolean. Since most constraint modules work in a similar way, it
914 should be simple to adapt them to work with Moose.
916 For instance, this is how you could use it with
917 L<Declare::Constraints::Simple> to declare a completely new type.
919 type 'HashOfArrayOfObjects',
923 -values => IsArrayRef(IsObject)
927 For more examples see the F<t/200_examples/004_example_w_DCS.t> test
930 Here is an example of using L<Test::Deep> and it's non-test
931 related C<eq_deeply> function.
933 type 'ArrayOfHashOfBarsAndRandomNumbers'
936 array_each(subhashof({
938 random_number => ignore()
942 For a complete example see the
943 F<t/200_examples/005_example_w_TestDeep.t> test file.
947 =head2 Type Constraint Constructors
949 The following functions are used to create type constraints. They
950 will also register the type constraints your create in a global
951 registry that is used to look types up by name.
953 See the L<SYNOPSIS> for an example of how to use these.
957 =item B<subtype 'Name' => as 'Parent' => where { } ...>
959 This creates a named subtype.
961 If you provide a parent that Moose does not recognize, it will
962 automatically create a new class type constraint for this name.
964 When creating a named type, the C<subtype> function should either be
965 called with the sugar helpers (C<where>, C<message>, etc), or with a
966 name and a hashref of parameters:
968 subtype( 'Foo', { where => ..., message => ... } );
970 The valid hashref keys are C<as> (the parent), C<where>, C<message>,
973 =item B<subtype as 'Parent' => where { } ...>
975 This creates an unnamed subtype and will return the type
976 constraint meta-object, which will be an instance of
977 L<Moose::Meta::TypeConstraint>.
979 When creating an anonymous type, the C<subtype> function should either
980 be called with the sugar helpers (C<where>, C<message>, etc), or with
981 just a hashref of parameters:
983 subtype( { where => ..., message => ... } );
985 =item B<class_type ($class, ?$options)>
987 Creates a new subtype of C<Object> with the name C<$class> and the
988 metaclass L<Moose::Meta::TypeConstraint::Class>.
990 =item B<role_type ($role, ?$options)>
992 Creates a C<Role> type constraint with the name C<$role> and the
993 metaclass L<Moose::Meta::TypeConstraint::Role>.
995 =item B<maybe_type ($type)>
997 Creates a type constraint for either C<undef> or something of the
1000 =item B<duck_type ($name, @methods)>
1002 This will create a subtype of Object and test to make sure the value
1003 C<can()> do the methods in C<@methods>.
1005 This is intended as an easy way to accept non-Moose objects that
1006 provide a certain interface. If you're using Moose classes, we
1007 recommend that you use a C<requires>-only Role instead.
1009 =item B<duck_type (\@methods)>
1011 If passed an ARRAY reference instead of the C<$name>, C<@methods>
1012 pair, this will create an unnamed duck type. This can be used in an
1013 attribute definiton like so:
1017 isa => duck_type( [qw( get_set )] ),
1020 =item B<enum ($name, @values)>
1022 This will create a basic subtype for a given set of strings.
1023 The resulting constraint will be a subtype of C<Str> and
1024 will match any of the items in C<@values>. It is case sensitive.
1025 See the L<SYNOPSIS> for a simple example.
1027 B<NOTE:> This is not a true proper enum type, it is simply
1028 a convenient constraint builder.
1030 =item B<enum (\@values)>
1032 If passed an ARRAY reference instead of the C<$name>, C<@values> pair,
1033 this will create an unnamed enum. This can then be used in an attribute
1036 has 'sort_order' => (
1038 isa => enum([qw[ ascending descending ]]),
1041 =item B<as 'Parent'>
1043 This is just sugar for the type constraint construction syntax.
1045 It takes a single argument, which is the name of a parent type.
1047 =item B<where { ... }>
1049 This is just sugar for the type constraint construction syntax.
1051 It takes a subroutine reference as an argument. When the type
1052 constraint is tested, the reference is run with the value to be tested
1053 in C<$_>. This reference should return true or false to indicate
1054 whether or not the constraint check passed.
1056 =item B<message { ... }>
1058 This is just sugar for the type constraint construction syntax.
1060 It takes a subroutine reference as an argument. When the type
1061 constraint fails, then the code block is run with the value provided
1062 in C<$_>. This reference should return a string, which will be used in
1063 the text of the exception thrown.
1065 =item B<optimize_as { ... }>
1067 This can be used to define a "hand optimized" version of your
1068 type constraint which can be used to avoid traversing a subtype
1069 constraint hierarchy.
1071 B<NOTE:> You should only use this if you know what you are doing,
1072 all the built in types use this, so your subtypes (assuming they
1073 are shallow) will not likely need to use this.
1075 =item B<type 'Name' => where { } ... >
1077 This creates a base type, which has no parent.
1079 The C<type> function should either be called with the sugar helpers
1080 (C<where>, C<message>, etc), or with a name and a hashref of
1083 type( 'Foo', { where => ..., message => ... } );
1085 The valid hashref keys are C<where>, C<message>, and C<optimize_as>.
1089 =head2 Type Coercion Constructors
1091 You can define coercions for type constraints, which allow you to
1092 automatically transform values to something valid for the type
1093 constraint. If you ask your accessor to coerce, then Moose will run
1094 the type-coercion code first, followed by the type constraint
1095 check. This feature should be used carefully as it is very powerful
1096 and could easily take off a limb if you are not careful.
1098 See the L<SYNOPSIS> for an example of how to use these.
1102 =item B<< coerce 'Name' => from 'OtherName' => via { ... } >>
1104 This defines a coercion from one type to another. The C<Name> argument
1105 is the type you are coercing I<to>.
1107 =item B<from 'OtherName'>
1109 This is just sugar for the type coercion construction syntax.
1111 It takes a single type name (or type object), which is the type being
1114 =item B<via { ... }>
1116 This is just sugar for the type coercion construction syntax.
1118 It takes a subroutine reference. This reference will be called with
1119 the value to be coerced in C<$_>. It is expected to return a new value
1120 of the proper type for the coercion.
1124 =head2 Creating and Finding Type Constraints
1126 These are additional functions for creating and finding type
1127 constraints. Most of these functions are not available for
1128 importing. The ones that are importable as specified.
1132 =item B<find_type_constraint($type_name)>
1134 This function can be used to locate the L<Moose::Meta::TypeConstraint>
1135 object for a named type.
1137 This function is importable.
1139 =item B<register_type_constraint($type_object)>
1141 This function will register a L<Moose::Meta::TypeConstraint> with the
1142 global type registry.
1144 This function is importable.
1146 =item B<normalize_type_constraint_name($type_constraint_name)>
1148 This method takes a type constraint name and returns the normalized
1149 form. This removes any whitespace in the string.
1151 =item B<create_type_constraint_union($pipe_separated_types | @type_constraint_names)>
1153 This can take a union type specification like C<'Int|ArrayRef[Int]'>,
1154 or a list of names. It returns a new
1155 L<Moose::Meta::TypeConstraint::Union> object.
1157 =item B<create_parameterized_type_constraint($type_name)>
1159 Given a C<$type_name> in the form of C<'BaseType[ContainerType]'>,
1160 this will create a new L<Moose::Meta::TypeConstraint::Parameterized>
1161 object. The C<BaseType> must exist already exist as a parameterizable
1164 =item B<create_class_type_constraint($class, $options)>
1166 Given a class name this function will create a new
1167 L<Moose::Meta::TypeConstraint::Class> object for that class name.
1169 The C<$options> is a hash reference that will be passed to the
1170 L<Moose::Meta::TypeConstraint::Class> constructor (as a hash).
1172 =item B<create_role_type_constraint($role, $options)>
1174 Given a role name this function will create a new
1175 L<Moose::Meta::TypeConstraint::Role> object for that role name.
1177 The C<$options> is a hash reference that will be passed to the
1178 L<Moose::Meta::TypeConstraint::Role> constructor (as a hash).
1180 =item B<create_enum_type_constraint($name, $values)>
1182 Given a enum name this function will create a new
1183 L<Moose::Meta::TypeConstraint::Enum> object for that enum name.
1185 =item B<find_or_parse_type_constraint($type_name)>
1187 Given a type name, this first attempts to find a matching constraint
1188 in the global registry.
1190 If the type name is a union or parameterized type, it will create a
1191 new object of the appropriate, but if given a "regular" type that does
1192 not yet exist, it simply returns false.
1194 When given a union or parameterized type, the member or base type must
1197 If it creates a new union or parameterized type, it will add it to the
1200 =item B<find_or_create_isa_type_constraint($type_name)>
1202 =item B<find_or_create_does_type_constraint($type_name)>
1204 These functions will first call C<find_or_parse_type_constraint>. If
1205 that function does not return a type, a new anonymous type object will
1208 The C<isa> variant will use C<create_class_type_constraint> and the
1209 C<does> variant will use C<create_role_type_constraint>.
1211 =item B<get_type_constraint_registry>
1213 Returns the L<Moose::Meta::TypeConstraint::Registry> object which
1214 keeps track of all type constraints.
1216 =item B<list_all_type_constraints>
1218 This will return a list of type constraint names in the global
1219 registry. You can then fetch the actual type object using
1220 C<find_type_constraint($type_name)>.
1222 =item B<list_all_builtin_type_constraints>
1224 This will return a list of builtin type constraints, meaning those
1225 which are defined in this module. See the L<Default Type Constraints>
1226 section for a complete list.
1228 =item B<export_type_constraints_as_functions>
1230 This will export all the current type constraints as functions into
1231 the caller's namespace (C<Int()>, C<Str()>, etc). Right now, this is
1232 mostly used for testing, but it might prove useful to others.
1234 =item B<get_all_parameterizable_types>
1236 This returns all the parameterizable types that have been registered,
1237 as a list of type objects.
1239 =item B<add_parameterizable_type($type)>
1241 Adds C<$type> to the list of parameterizable types
1247 All complex software has bugs lurking in it, and this module is no
1248 exception. If you find a bug please either email me, or add the bug
1253 Stevan Little E<lt>stevan@iinteractive.comE<gt>
1255 =head1 COPYRIGHT AND LICENSE
1257 Copyright 2006-2009 by Infinity Interactive, Inc.
1259 L<http://www.iinteractive.com>
1261 This library is free software; you can redistribute it and/or modify
1262 it under the same terms as Perl itself.