2 package Moose::Util::TypeConstraints;
5 use List::MoreUtils qw( all any );
6 use Scalar::Util qw( blessed reftype );
10 $VERSION = eval $VERSION;
11 our $AUTHORITY = 'cpan:STEVAN';
13 ## --------------------------------------------------------
14 # Prototyped subs must be predeclared because we have a
15 # circular dependency with Moose::Meta::Attribute et. al.
16 # so in case of us being use'd first the predeclaration
17 # ensures the prototypes are in scope when consumers are
26 ## --------------------------------------------------------
28 use Moose::Meta::TypeConstraint;
29 use Moose::Meta::TypeConstraint::Union;
30 use Moose::Meta::TypeConstraint::Parameterized;
31 use Moose::Meta::TypeConstraint::Parameterizable;
32 use Moose::Meta::TypeConstraint::Class;
33 use Moose::Meta::TypeConstraint::Role;
34 use Moose::Meta::TypeConstraint::Enum;
35 use Moose::Meta::TypeCoercion;
36 use Moose::Meta::TypeCoercion::Union;
37 use Moose::Meta::TypeConstraint::Registry;
38 use Moose::Util::TypeConstraints::OptimizedConstraints;
40 Moose::Exporter->setup_import_methods(
43 type subtype class_type role_type maybe_type duck_type
44 as where message optimize_as
48 register_type_constraint )
53 ## --------------------------------------------------------
54 ## type registry and some useful functions for it
55 ## --------------------------------------------------------
57 my $REGISTRY = Moose::Meta::TypeConstraint::Registry->new;
59 sub get_type_constraint_registry {$REGISTRY}
60 sub list_all_type_constraints { keys %{ $REGISTRY->type_constraints } }
62 sub export_type_constraints_as_functions {
65 foreach my $constraint ( keys %{ $REGISTRY->type_constraints } ) {
66 my $tc = $REGISTRY->get_type_constraint($constraint)
67 ->_compiled_type_constraint;
68 *{"${pkg}::${constraint}"}
69 = sub { $tc->( $_[0] ) ? 1 : undef }; # the undef is for compat
73 sub create_type_constraint_union {
74 my @type_constraint_names;
76 if ( scalar @_ == 1 && _detect_type_constraint_union( $_[0] ) ) {
77 @type_constraint_names = _parse_type_constraint_union( $_[0] );
80 @type_constraint_names = @_;
83 ( scalar @type_constraint_names >= 2 )
84 || __PACKAGE__->_throw_error(
85 "You must pass in at least 2 type names to make a union");
87 my @type_constraints = map {
88 find_or_parse_type_constraint($_)
89 || __PACKAGE__->_throw_error(
90 "Could not locate type constraint ($_) for the union");
91 } @type_constraint_names;
93 return Moose::Meta::TypeConstraint::Union->new(
94 type_constraints => \@type_constraints );
97 sub create_parameterized_type_constraint {
98 my $type_constraint_name = shift;
99 my ( $base_type, $type_parameter )
100 = _parse_parameterized_type_constraint($type_constraint_name);
102 ( defined $base_type && defined $type_parameter )
103 || __PACKAGE__->_throw_error(
104 "Could not parse type name ($type_constraint_name) correctly");
106 if ( $REGISTRY->has_type_constraint($base_type) ) {
107 my $base_type_tc = $REGISTRY->get_type_constraint($base_type);
108 return _create_parameterized_type_constraint(
114 __PACKAGE__->_throw_error(
115 "Could not locate the base type ($base_type)");
119 sub _create_parameterized_type_constraint {
120 my ( $base_type_tc, $type_parameter ) = @_;
121 if ( $base_type_tc->can('parameterize') ) {
122 return $base_type_tc->parameterize($type_parameter);
125 return Moose::Meta::TypeConstraint::Parameterized->new(
126 name => $base_type_tc->name . '[' . $type_parameter . ']',
127 parent => $base_type_tc,
129 find_or_create_isa_type_constraint($type_parameter),
134 #should we also support optimized checks?
135 sub create_class_type_constraint {
136 my ( $class, $options ) = @_;
138 # too early for this check
139 #find_type_constraint("ClassName")->check($class)
140 # || __PACKAGE__->_throw_error("Can't create a class type constraint because '$class' is not a class name");
148 $options{name} ||= "__ANON__";
150 Moose::Meta::TypeConstraint::Class->new(%options);
153 sub create_role_type_constraint {
154 my ( $role, $options ) = @_;
156 # too early for this check
157 #find_type_constraint("ClassName")->check($class)
158 # || __PACKAGE__->_throw_error("Can't create a class type constraint because '$class' is not a class name");
166 $options{name} ||= "__ANON__";
168 Moose::Meta::TypeConstraint::Role->new(%options);
171 sub find_or_create_type_constraint {
172 my ( $type_constraint_name, $options_for_anon_type ) = @_;
175 = find_or_parse_type_constraint($type_constraint_name) ) {
178 elsif ( defined $options_for_anon_type ) {
181 # if there is no $options_for_anon_type
182 # specified, then we assume they don't
183 # want to create one, and return nothing.
185 # otherwise assume that we should create
186 # an ANON type with the $options_for_anon_type
187 # options which can be passed in. It should
188 # be noted that these don't get registered
189 # so we need to return it.
191 return Moose::Meta::TypeConstraint->new(
193 %{$options_for_anon_type}
200 sub find_or_create_isa_type_constraint {
201 my $type_constraint_name = shift;
202 find_or_parse_type_constraint($type_constraint_name)
203 || create_class_type_constraint($type_constraint_name);
206 sub find_or_create_does_type_constraint {
207 my $type_constraint_name = shift;
208 find_or_parse_type_constraint($type_constraint_name)
209 || create_role_type_constraint($type_constraint_name);
212 sub find_or_parse_type_constraint {
213 my $type_constraint_name = normalize_type_constraint_name(shift);
216 if ( $constraint = find_type_constraint($type_constraint_name) ) {
219 elsif ( _detect_type_constraint_union($type_constraint_name) ) {
220 $constraint = create_type_constraint_union($type_constraint_name);
222 elsif ( _detect_parameterized_type_constraint($type_constraint_name) ) {
224 = create_parameterized_type_constraint($type_constraint_name);
230 $REGISTRY->add_type_constraint($constraint);
234 sub normalize_type_constraint_name {
235 my $type_constraint_name = shift;
236 $type_constraint_name =~ s/\s//g;
237 return $type_constraint_name;
243 local $Carp::CarpLevel = $Carp::CarpLevel + 1;
244 Carp::confess($error);
247 ## --------------------------------------------------------
248 ## exported functions ...
249 ## --------------------------------------------------------
251 sub find_type_constraint {
254 if ( blessed $type and $type->isa("Moose::Meta::TypeConstraint") ) {
258 return unless $REGISTRY->has_type_constraint($type);
259 return $REGISTRY->get_type_constraint($type);
263 sub register_type_constraint {
264 my $constraint = shift;
265 __PACKAGE__->_throw_error("can't register an unnamed type constraint")
266 unless defined $constraint->name;
267 $REGISTRY->add_type_constraint($constraint);
275 # back-compat version, called without sugar
276 if ( !any { ( reftype($_) || '' ) eq 'HASH' } @_ ) {
277 return _create_type_constraint( $_[0], undef, $_[1] );
282 my %p = map { %{$_} } @_;
284 return _create_type_constraint(
285 $name, undef, $p{where}, $p{message},
292 # crazy back-compat code for being called without sugar ...
294 # subtype 'Parent', sub { where };
295 if ( scalar @_ == 2 && ( reftype( $_[1] ) || '' ) eq 'CODE' ) {
296 return _create_type_constraint( undef, @_ );
299 # subtype 'Parent', sub { where }, sub { message };
300 # subtype 'Parent', sub { where }, sub { message }, sub { optimized };
301 if ( scalar @_ >= 3 && all { ( reftype($_) || '' ) eq 'CODE' }
303 return _create_type_constraint( undef, @_ );
306 # subtype 'Name', 'Parent', ...
307 if ( scalar @_ >= 2 && all { !ref } @_[ 0, 1 ] ) {
308 return _create_type_constraint(@_);
311 if ( @_ == 1 && !ref $_[0] ) {
312 __PACKAGE__->_throw_error(
313 'A subtype cannot consist solely of a name, it must have a parent'
317 # The blessed check is mostly to accommodate MooseX::Types, which
318 # uses an object which overloads stringification as a type name.
319 my $name = ref $_[0] && !blessed $_[0] ? undef : shift;
321 my %p = map { %{$_} } @_;
323 # subtype Str => where { ... };
324 if ( !exists $p{as} ) {
329 return _create_type_constraint(
330 $name, $p{as}, $p{where}, $p{message},
336 register_type_constraint(
337 create_class_type_constraint(
339 ( defined( $_[1] ) ? $_[1] : () ),
344 sub role_type ($;$) {
345 register_type_constraint(
346 create_role_type_constraint(
348 ( defined( $_[1] ) ? $_[1] : () ),
354 my ($type_parameter) = @_;
356 register_type_constraint(
357 $REGISTRY->get_type_constraint('Maybe')->parameterize($type_parameter)
362 my ( $type_name, @methods ) = @_;
363 if ( ref $type_name eq 'ARRAY' && !@methods ) {
364 @methods = @$type_name;
368 register_type_constraint(
369 _create_type_constraint(
374 return 0 unless all { $obj->can($_) } @methods;
379 my @missing_methods = grep { !$obj->can($_) } @methods;
381 "${\blessed($obj)} is missing methods '@missing_methods'";
388 my ( $type_name, @coercion_map ) = @_;
389 _install_type_coercions( $type_name, \@coercion_map );
392 # The trick of returning @_ lets us avoid having to specify a
393 # prototype. Perl will parse this:
401 # subtype( 'Foo', as( 'Str', where { ... } ) );
403 # If as() returns all it's extra arguments, this just works, and
404 # preserves backwards compatibility.
405 sub as { { as => shift }, @_ }
406 sub where (&) { { where => $_[0] } }
407 sub message (&) { { message => $_[0] } }
408 sub optimize_as (&) { { optimize_as => $_[0] } }
411 sub via (&) { $_[0] }
414 my ( $type_name, @values ) = @_;
417 # if only an array-ref is passed then
418 # you get an anon-enum
420 if ( ref $type_name eq 'ARRAY' && !@values ) {
421 @values = @$type_name;
424 ( scalar @values >= 2 )
425 || __PACKAGE__->_throw_error(
426 "You must have at least two values to enumerate through");
427 my %valid = map { $_ => 1 } @values;
429 register_type_constraint(
430 create_enum_type_constraint(
437 sub create_enum_type_constraint {
438 my ( $type_name, $values ) = @_;
440 Moose::Meta::TypeConstraint::Enum->new(
441 name => $type_name || '__ANON__',
446 ## --------------------------------------------------------
447 ## desugaring functions ...
448 ## --------------------------------------------------------
450 sub _create_type_constraint ($$$;$$) {
455 my $optimized = shift;
457 my $pkg_defined_in = scalar( caller(1) );
459 if ( defined $name ) {
460 my $type = $REGISTRY->get_type_constraint($name);
462 ( $type->_package_defined_in eq $pkg_defined_in )
464 "The type constraint '$name' has already been created in "
465 . $type->_package_defined_in
466 . " and cannot be created again in "
470 $name =~ /^[\w:\.]+$/
471 or die qq{$name contains invalid characters for a type name.}
472 . qq{ Names can contain alphanumeric character, ":", and "."\n};
477 package_defined_in => $pkg_defined_in,
479 ( $check ? ( constraint => $check ) : () ),
480 ( $message ? ( message => $message ) : () ),
481 ( $optimized ? ( optimized => $optimized ) : () ),
490 : find_or_create_isa_type_constraint($parent)
492 $constraint = $parent->create_child_type(%opts);
495 $constraint = Moose::Meta::TypeConstraint->new(%opts);
498 $REGISTRY->add_type_constraint($constraint)
504 sub _install_type_coercions ($$) {
505 my ( $type_name, $coercion_map ) = @_;
506 my $type = find_type_constraint($type_name);
508 || __PACKAGE__->_throw_error(
509 "Cannot find type '$type_name', perhaps you forgot to load it.");
510 if ( $type->has_coercion ) {
511 $type->coercion->add_type_coercions(@$coercion_map);
514 my $type_coercion = Moose::Meta::TypeCoercion->new(
515 type_coercion_map => $coercion_map,
516 type_constraint => $type
518 $type->coercion($type_coercion);
522 ## --------------------------------------------------------
523 ## type notation parsing ...
524 ## --------------------------------------------------------
528 # All I have to say is mugwump++ cause I know
529 # do not even have enough regexp-fu to be able
530 # to have written this (I can only barely
531 # understand it as it is)
536 my $valid_chars = qr{[\w:\.]};
537 my $type_atom = qr{ $valid_chars+ };
541 my $type = qr{ $valid_chars+ (?: \[ \s* (??{$any}) \s* \] )? }x;
542 my $type_capture_parts
543 = qr{ ($valid_chars+) (?: \[ \s* ((??{$any})) \s* \] )? }x;
544 my $type_with_parameter
545 = qr{ $valid_chars+ \[ \s* (??{$any}) \s* \] }x;
547 my $op_union = qr{ \s* \| \s* }x;
548 my $union = qr{ $type (?: $op_union $type )+ }x;
550 $any = qr{ $type | $union }x;
552 sub _parse_parameterized_type_constraint {
553 { no warnings 'void'; $any; } # force capture of interpolated lexical
554 $_[0] =~ m{ $type_capture_parts }x;
558 sub _detect_parameterized_type_constraint {
559 { no warnings 'void'; $any; } # force capture of interpolated lexical
560 $_[0] =~ m{ ^ $type_with_parameter $ }x;
563 sub _parse_type_constraint_union {
564 { no warnings 'void'; $any; } # force capture of interpolated lexical
567 while ( $given =~ m{ \G (?: $op_union )? ($type) }gcx ) {
570 ( pos($given) eq length($given) )
571 || __PACKAGE__->_throw_error( "'$given' didn't parse (parse-pos="
579 sub _detect_type_constraint_union {
580 { no warnings 'void'; $any; } # force capture of interpolated lexical
581 $_[0] =~ m{^ $type $op_union $type ( $op_union .* )? $}x;
585 ## --------------------------------------------------------
586 # define some basic built-in types
587 ## --------------------------------------------------------
589 # By making these classes immutable before creating all the types we
590 # below, we avoid repeatedly calling the slow MOP-based accessors.
592 inline_constructor => 1,
593 constructor_name => "_new",
595 # these are Class::MOP accessors, so they need inlining
596 inline_accessors => 1
597 ) for grep { $_->is_mutable }
598 map { Class::MOP::class_of($_) }
600 Moose::Meta::TypeConstraint
601 Moose::Meta::TypeConstraint::Union
602 Moose::Meta::TypeConstraint::Parameterized
603 Moose::Meta::TypeConstraint::Parameterizable
604 Moose::Meta::TypeConstraint::Class
605 Moose::Meta::TypeConstraint::Role
606 Moose::Meta::TypeConstraint::Enum
607 Moose::Meta::TypeConstraint::Registry
610 type 'Any' => where {1}; # meta-type including all
611 subtype 'Item' => as 'Any'; # base-type
613 subtype 'Undef' => as 'Item' => where { !defined($_) };
614 subtype 'Defined' => as 'Item' => where { defined($_) };
616 subtype 'Bool' => as 'Item' =>
617 where { !defined($_) || $_ eq "" || "$_" eq '1' || "$_" eq '0' };
619 subtype 'Value' => as 'Defined' => where { !ref($_) } =>
620 optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::Value;
622 subtype 'Ref' => as 'Defined' => where { ref($_) } =>
623 optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::Ref;
625 subtype 'Str' => as 'Value' => where {1} =>
626 optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::Str;
628 subtype 'Num' => as 'Str' =>
629 where { Scalar::Util::looks_like_number($_) } =>
630 optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::Num;
632 subtype 'Int' => as 'Num' => where { "$_" =~ /^-?[0-9]+$/ } =>
633 optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::Int;
635 subtype 'ScalarRef' => as 'Ref' => where { ref($_) eq 'SCALAR' } =>
637 \&Moose::Util::TypeConstraints::OptimizedConstraints::ScalarRef;
638 subtype 'CodeRef' => as 'Ref' => where { ref($_) eq 'CODE' } =>
639 optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::CodeRef;
640 subtype 'RegexpRef' => as 'Ref' => where { ref($_) eq 'Regexp' } =>
642 \&Moose::Util::TypeConstraints::OptimizedConstraints::RegexpRef;
643 subtype 'GlobRef' => as 'Ref' => where { ref($_) eq 'GLOB' } =>
644 optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::GlobRef;
647 # scalar filehandles are GLOB refs,
648 # but a GLOB ref is not always a filehandle
649 subtype 'FileHandle' => as 'GlobRef' => where {
650 Scalar::Util::openhandle($_) || ( blessed($_) && $_->isa("IO::Handle") );
652 \&Moose::Util::TypeConstraints::OptimizedConstraints::FileHandle;
655 # blessed(qr/.../) returns true,.. how odd
656 subtype 'Object' => as 'Ref' =>
657 where { blessed($_) && blessed($_) ne 'Regexp' } =>
658 optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::Object;
660 subtype 'Role' => as 'Object' => where { $_->can('does') } =>
661 optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::Role;
663 my $_class_name_checker = sub { };
665 subtype 'ClassName' => as 'Str' =>
666 where { Class::MOP::is_class_loaded($_) } => optimize_as
667 \&Moose::Util::TypeConstraints::OptimizedConstraints::ClassName;
669 subtype 'RoleName' => as 'ClassName' => where {
670 (Class::MOP::class_of($_) || return)->isa('Moose::Meta::Role');
672 \&Moose::Util::TypeConstraints::OptimizedConstraints::RoleName;
674 ## --------------------------------------------------------
675 # parameterizable types ...
677 $REGISTRY->add_type_constraint(
678 Moose::Meta::TypeConstraint::Parameterizable->new(
680 package_defined_in => __PACKAGE__,
681 parent => find_type_constraint('Ref'),
682 constraint => sub { ref($_) eq 'ARRAY' },
684 \&Moose::Util::TypeConstraints::OptimizedConstraints::ArrayRef,
685 constraint_generator => sub {
686 my $type_parameter = shift;
687 my $check = $type_parameter->_compiled_type_constraint;
689 foreach my $x (@$_) {
690 ( $check->($x) ) || return;
698 $REGISTRY->add_type_constraint(
699 Moose::Meta::TypeConstraint::Parameterizable->new(
701 package_defined_in => __PACKAGE__,
702 parent => find_type_constraint('Ref'),
703 constraint => sub { ref($_) eq 'HASH' },
705 \&Moose::Util::TypeConstraints::OptimizedConstraints::HashRef,
706 constraint_generator => sub {
707 my $type_parameter = shift;
708 my $check = $type_parameter->_compiled_type_constraint;
710 foreach my $x ( values %$_ ) {
711 ( $check->($x) ) || return;
719 $REGISTRY->add_type_constraint(
720 Moose::Meta::TypeConstraint::Parameterizable->new(
722 package_defined_in => __PACKAGE__,
723 parent => find_type_constraint('Item'),
724 constraint => sub {1},
725 constraint_generator => sub {
726 my $type_parameter = shift;
727 my $check = $type_parameter->_compiled_type_constraint;
729 return 1 if not( defined($_) ) || $check->($_);
736 my @PARAMETERIZABLE_TYPES
737 = map { $REGISTRY->get_type_constraint($_) } qw[ArrayRef HashRef Maybe];
739 sub get_all_parameterizable_types {@PARAMETERIZABLE_TYPES}
741 sub add_parameterizable_type {
744 && $type->isa('Moose::Meta::TypeConstraint::Parameterizable') )
745 || __PACKAGE__->_throw_error(
746 "Type must be a Moose::Meta::TypeConstraint::Parameterizable not $type"
748 push @PARAMETERIZABLE_TYPES => $type;
751 ## --------------------------------------------------------
752 # end of built-in types ...
753 ## --------------------------------------------------------
756 my @BUILTINS = list_all_type_constraints();
757 sub list_all_builtin_type_constraints {@BUILTINS}
764 goto &Moose::throw_error;
775 Moose::Util::TypeConstraints - Type constraint system for Moose
779 use Moose::Util::TypeConstraints;
785 subtype 'NaturalLessThanTen'
788 => message { "This number ($_) is not less than ten!" };
794 enum 'RGBColors' => qw(red green blue);
796 no Moose::Util::TypeConstraints;
800 This module provides Moose with the ability to create custom type
801 constraints to be used in attribute definition.
803 =head2 Important Caveat
805 This is B<NOT> a type system for Perl 5. These are type constraints,
806 and they are not used by Moose unless you tell it to. No type
807 inference is performed, expressions are not typed, etc. etc. etc.
809 A type constraint is at heart a small "check if a value is valid"
810 function. A constraint can be associated with an attribute. This
811 simplifies parameter validation, and makes your code clearer to read,
812 because you can refer to constraints by name.
814 =head2 Slightly Less Important Caveat
816 It is B<always> a good idea to quote your type names.
818 This prevents Perl from trying to execute the call as an indirect
819 object call. This can be an issue when you have a subtype with the
820 same name as a valid class.
824 subtype DateTime => as Object => where { $_->isa('DateTime') };
826 will I<just work>, while this:
829 subtype DateTime => as Object => where { $_->isa('DateTime') };
831 will fail silently and cause many headaches. The simple way to solve
832 this, as well as future proof your subtypes from classes which have
833 yet to have been created, is to quote the type name:
836 subtype 'DateTime' => as 'Object' => where { $_->isa('DateTime') };
838 =head2 Default Type Constraints
840 This module also provides a simple hierarchy for Perl 5 types, here is
841 that hierarchy represented visually.
866 B<NOTE:> Any type followed by a type parameter C<[`a]> can be
867 parameterized, this means you can say:
869 ArrayRef[Int] # an array of integers
870 HashRef[CodeRef] # a hash of str to CODE ref mappings
871 Maybe[Str] # value may be a string, may be undefined
873 If Moose finds a name in brackets that it does not recognize as an
874 existing type, it assumes that this is a class name, for example
875 C<ArrayRef[DateTime]>.
877 B<NOTE:> Unless you parameterize a type, then it is invalid to include
878 the square brackets. I.e. C<ArrayRef[]> will be treated as a new type
879 name, I<not> as a parameterization of C<ArrayRef>.
881 B<NOTE:> The C<Undef> type constraint for the most part works
882 correctly now, but edge cases may still exist, please use it
885 B<NOTE:> The C<ClassName> type constraint does a complex package
886 existence check. This means that your class B<must> be loaded for this
887 type constraint to pass.
889 B<NOTE:> The C<RoleName> constraint checks a string is a I<package
890 name> which is a role, like C<'MyApp::Role::Comparable'>. The C<Role>
891 constraint checks that an I<object does> the named role.
893 =head2 Type Constraint Naming
895 Type name declared via this module can only contain alphanumeric
896 characters, colons (:), and periods (.).
898 Since the types created by this module are global, it is suggested
899 that you namespace your types just as you would namespace your
900 modules. So instead of creating a I<Color> type for your
901 B<My::Graphics> module, you would call the type
902 I<My::Graphics::Types::Color> instead.
904 =head2 Use with Other Constraint Modules
906 This module can play nicely with other constraint modules with some
907 slight tweaking. The C<where> clause in types is expected to be a
908 C<CODE> reference which checks it's first argument and returns a
909 boolean. Since most constraint modules work in a similar way, it
910 should be simple to adapt them to work with Moose.
912 For instance, this is how you could use it with
913 L<Declare::Constraints::Simple> to declare a completely new type.
915 type 'HashOfArrayOfObjects',
919 -values => IsArrayRef(IsObject)
923 For more examples see the F<t/200_examples/004_example_w_DCS.t> test
926 Here is an example of using L<Test::Deep> and it's non-test
927 related C<eq_deeply> function.
929 type 'ArrayOfHashOfBarsAndRandomNumbers'
932 array_each(subhashof({
934 random_number => ignore()
938 For a complete example see the
939 F<t/200_examples/005_example_w_TestDeep.t> test file.
943 =head2 Type Constraint Constructors
945 The following functions are used to create type constraints. They
946 will also register the type constraints your create in a global
947 registry that is used to look types up by name.
949 See the L<SYNOPSIS> for an example of how to use these.
953 =item B<< subtype 'Name' => as 'Parent' => where { } ... >>
955 This creates a named subtype.
957 If you provide a parent that Moose does not recognize, it will
958 automatically create a new class type constraint for this name.
960 When creating a named type, the C<subtype> function should either be
961 called with the sugar helpers (C<where>, C<message>, etc), or with a
962 name and a hashref of parameters:
964 subtype( 'Foo', { where => ..., message => ... } );
966 The valid hashref keys are C<as> (the parent), C<where>, C<message>,
969 =item B<< subtype as 'Parent' => where { } ... >>
971 This creates an unnamed subtype and will return the type
972 constraint meta-object, which will be an instance of
973 L<Moose::Meta::TypeConstraint>.
975 When creating an anonymous type, the C<subtype> function should either
976 be called with the sugar helpers (C<where>, C<message>, etc), or with
977 just a hashref of parameters:
979 subtype( { where => ..., message => ... } );
981 =item B<class_type ($class, ?$options)>
983 Creates a new subtype of C<Object> with the name C<$class> and the
984 metaclass L<Moose::Meta::TypeConstraint::Class>.
986 =item B<role_type ($role, ?$options)>
988 Creates a C<Role> type constraint with the name C<$role> and the
989 metaclass L<Moose::Meta::TypeConstraint::Role>.
991 =item B<maybe_type ($type)>
993 Creates a type constraint for either C<undef> or something of the
996 =item B<duck_type ($name, @methods)>
998 This will create a subtype of Object and test to make sure the value
999 C<can()> do the methods in C<@methods>.
1001 This is intended as an easy way to accept non-Moose objects that
1002 provide a certain interface. If you're using Moose classes, we
1003 recommend that you use a C<requires>-only Role instead.
1005 =item B<duck_type (\@methods)>
1007 If passed an ARRAY reference instead of the C<$name>, C<@methods>
1008 pair, this will create an unnamed duck type. This can be used in an
1009 attribute definition like so:
1013 isa => duck_type( [qw( get_set )] ),
1016 =item B<enum ($name, @values)>
1018 This will create a basic subtype for a given set of strings.
1019 The resulting constraint will be a subtype of C<Str> and
1020 will match any of the items in C<@values>. It is case sensitive.
1021 See the L<SYNOPSIS> for a simple example.
1023 B<NOTE:> This is not a true proper enum type, it is simply
1024 a convenient constraint builder.
1026 =item B<enum (\@values)>
1028 If passed an ARRAY reference instead of the C<$name>, C<@values> pair,
1029 this will create an unnamed enum. This can then be used in an attribute
1032 has 'sort_order' => (
1034 isa => enum([qw[ ascending descending ]]),
1037 =item B<as 'Parent'>
1039 This is just sugar for the type constraint construction syntax.
1041 It takes a single argument, which is the name of a parent type.
1043 =item B<where { ... }>
1045 This is just sugar for the type constraint construction syntax.
1047 It takes a subroutine reference as an argument. When the type
1048 constraint is tested, the reference is run with the value to be tested
1049 in C<$_>. This reference should return true or false to indicate
1050 whether or not the constraint check passed.
1052 =item B<message { ... }>
1054 This is just sugar for the type constraint construction syntax.
1056 It takes a subroutine reference as an argument. When the type
1057 constraint fails, then the code block is run with the value provided
1058 in C<$_>. This reference should return a string, which will be used in
1059 the text of the exception thrown.
1061 =item B<optimize_as { ... }>
1063 This can be used to define a "hand optimized" version of your
1064 type constraint which can be used to avoid traversing a subtype
1065 constraint hierarchy.
1067 B<NOTE:> You should only use this if you know what you are doing,
1068 all the built in types use this, so your subtypes (assuming they
1069 are shallow) will not likely need to use this.
1071 =item B<type 'Name' => where { } ... >
1073 This creates a base type, which has no parent.
1075 The C<type> function should either be called with the sugar helpers
1076 (C<where>, C<message>, etc), or with a name and a hashref of
1079 type( 'Foo', { where => ..., message => ... } );
1081 The valid hashref keys are C<where>, C<message>, and C<optimize_as>.
1085 =head2 Type Coercion Constructors
1087 You can define coercions for type constraints, which allow you to
1088 automatically transform values to something valid for the type
1089 constraint. If you ask your accessor to coerce, then Moose will run
1090 the type-coercion code first, followed by the type constraint
1091 check. This feature should be used carefully as it is very powerful
1092 and could easily take off a limb if you are not careful.
1094 See the L<SYNOPSIS> for an example of how to use these.
1098 =item B<< coerce 'Name' => from 'OtherName' => via { ... } >>
1100 This defines a coercion from one type to another. The C<Name> argument
1101 is the type you are coercing I<to>.
1103 =item B<from 'OtherName'>
1105 This is just sugar for the type coercion construction syntax.
1107 It takes a single type name (or type object), which is the type being
1110 =item B<via { ... }>
1112 This is just sugar for the type coercion construction syntax.
1114 It takes a subroutine reference. This reference will be called with
1115 the value to be coerced in C<$_>. It is expected to return a new value
1116 of the proper type for the coercion.
1120 =head2 Creating and Finding Type Constraints
1122 These are additional functions for creating and finding type
1123 constraints. Most of these functions are not available for
1124 importing. The ones that are importable as specified.
1128 =item B<find_type_constraint($type_name)>
1130 This function can be used to locate the L<Moose::Meta::TypeConstraint>
1131 object for a named type.
1133 This function is importable.
1135 =item B<register_type_constraint($type_object)>
1137 This function will register a L<Moose::Meta::TypeConstraint> with the
1138 global type registry.
1140 This function is importable.
1142 =item B<normalize_type_constraint_name($type_constraint_name)>
1144 This method takes a type constraint name and returns the normalized
1145 form. This removes any whitespace in the string.
1147 =item B<create_type_constraint_union($pipe_separated_types | @type_constraint_names)>
1149 This can take a union type specification like C<'Int|ArrayRef[Int]'>,
1150 or a list of names. It returns a new
1151 L<Moose::Meta::TypeConstraint::Union> object.
1153 =item B<create_parameterized_type_constraint($type_name)>
1155 Given a C<$type_name> in the form of C<'BaseType[ContainerType]'>,
1156 this will create a new L<Moose::Meta::TypeConstraint::Parameterized>
1157 object. The C<BaseType> must exist already exist as a parameterizable
1160 =item B<create_class_type_constraint($class, $options)>
1162 Given a class name this function will create a new
1163 L<Moose::Meta::TypeConstraint::Class> object for that class name.
1165 The C<$options> is a hash reference that will be passed to the
1166 L<Moose::Meta::TypeConstraint::Class> constructor (as a hash).
1168 =item B<create_role_type_constraint($role, $options)>
1170 Given a role name this function will create a new
1171 L<Moose::Meta::TypeConstraint::Role> object for that role name.
1173 The C<$options> is a hash reference that will be passed to the
1174 L<Moose::Meta::TypeConstraint::Role> constructor (as a hash).
1176 =item B<create_enum_type_constraint($name, $values)>
1178 Given a enum name this function will create a new
1179 L<Moose::Meta::TypeConstraint::Enum> object for that enum name.
1181 =item B<find_or_parse_type_constraint($type_name)>
1183 Given a type name, this first attempts to find a matching constraint
1184 in the global registry.
1186 If the type name is a union or parameterized type, it will create a
1187 new object of the appropriate, but if given a "regular" type that does
1188 not yet exist, it simply returns false.
1190 When given a union or parameterized type, the member or base type must
1193 If it creates a new union or parameterized type, it will add it to the
1196 =item B<find_or_create_isa_type_constraint($type_name)>
1198 =item B<find_or_create_does_type_constraint($type_name)>
1200 These functions will first call C<find_or_parse_type_constraint>. If
1201 that function does not return a type, a new anonymous type object will
1204 The C<isa> variant will use C<create_class_type_constraint> and the
1205 C<does> variant will use C<create_role_type_constraint>.
1207 =item B<get_type_constraint_registry>
1209 Returns the L<Moose::Meta::TypeConstraint::Registry> object which
1210 keeps track of all type constraints.
1212 =item B<list_all_type_constraints>
1214 This will return a list of type constraint names in the global
1215 registry. You can then fetch the actual type object using
1216 C<find_type_constraint($type_name)>.
1218 =item B<list_all_builtin_type_constraints>
1220 This will return a list of builtin type constraints, meaning those
1221 which are defined in this module. See the L<Default Type Constraints>
1222 section for a complete list.
1224 =item B<export_type_constraints_as_functions>
1226 This will export all the current type constraints as functions into
1227 the caller's namespace (C<Int()>, C<Str()>, etc). Right now, this is
1228 mostly used for testing, but it might prove useful to others.
1230 =item B<get_all_parameterizable_types>
1232 This returns all the parameterizable types that have been registered,
1233 as a list of type objects.
1235 =item B<add_parameterizable_type($type)>
1237 Adds C<$type> to the list of parameterizable types
1243 All complex software has bugs lurking in it, and this module is no
1244 exception. If you find a bug please either email me, or add the bug
1249 Stevan Little E<lt>stevan@iinteractive.comE<gt>
1251 =head1 COPYRIGHT AND LICENSE
1253 Copyright 2006-2009 by Infinity Interactive, Inc.
1255 L<http://www.iinteractive.com>
1257 This library is free software; you can redistribute it and/or modify
1258 it under the same terms as Perl itself.