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::TypeConstraint::DuckType;
36 use Moose::Meta::TypeCoercion;
37 use Moose::Meta::TypeCoercion::Union;
38 use Moose::Meta::TypeConstraint::Registry;
39 use Moose::Util::TypeConstraints::OptimizedConstraints;
41 Moose::Exporter->setup_import_methods(
44 type subtype class_type role_type maybe_type duck_type
45 as where message optimize_as
49 register_type_constraint
54 ## --------------------------------------------------------
55 ## type registry and some useful functions for it
56 ## --------------------------------------------------------
58 my $REGISTRY = Moose::Meta::TypeConstraint::Registry->new;
60 sub get_type_constraint_registry {$REGISTRY}
61 sub list_all_type_constraints { keys %{ $REGISTRY->type_constraints } }
63 sub export_type_constraints_as_functions {
66 foreach my $constraint ( keys %{ $REGISTRY->type_constraints } ) {
67 my $tc = $REGISTRY->get_type_constraint($constraint)
68 ->_compiled_type_constraint;
69 *{"${pkg}::${constraint}"}
70 = sub { $tc->( $_[0] ) ? 1 : undef }; # the undef is for compat
74 sub create_type_constraint_union {
75 my @type_constraint_names;
77 if ( scalar @_ == 1 && _detect_type_constraint_union( $_[0] ) ) {
78 @type_constraint_names = _parse_type_constraint_union( $_[0] );
81 @type_constraint_names = @_;
84 ( scalar @type_constraint_names >= 2 )
85 || __PACKAGE__->_throw_error(
86 "You must pass in at least 2 type names to make a union");
88 my @type_constraints = map {
89 find_or_parse_type_constraint($_)
90 || __PACKAGE__->_throw_error(
91 "Could not locate type constraint ($_) for the union");
92 } @type_constraint_names;
94 return Moose::Meta::TypeConstraint::Union->new(
95 type_constraints => \@type_constraints );
98 sub create_parameterized_type_constraint {
99 my $type_constraint_name = shift;
100 my ( $base_type, $type_parameter )
101 = _parse_parameterized_type_constraint($type_constraint_name);
103 ( defined $base_type && defined $type_parameter )
104 || __PACKAGE__->_throw_error(
105 "Could not parse type name ($type_constraint_name) correctly");
107 if ( $REGISTRY->has_type_constraint($base_type) ) {
108 my $base_type_tc = $REGISTRY->get_type_constraint($base_type);
109 return _create_parameterized_type_constraint(
115 __PACKAGE__->_throw_error(
116 "Could not locate the base type ($base_type)");
120 sub _create_parameterized_type_constraint {
121 my ( $base_type_tc, $type_parameter ) = @_;
122 if ( $base_type_tc->can('parameterize') ) {
123 return $base_type_tc->parameterize($type_parameter);
126 return Moose::Meta::TypeConstraint::Parameterized->new(
127 name => $base_type_tc->name . '[' . $type_parameter . ']',
128 parent => $base_type_tc,
130 find_or_create_isa_type_constraint($type_parameter),
135 #should we also support optimized checks?
136 sub create_class_type_constraint {
137 my ( $class, $options ) = @_;
139 # too early for this check
140 #find_type_constraint("ClassName")->check($class)
141 # || __PACKAGE__->_throw_error("Can't create a class type constraint because '$class' is not a class name");
149 $options{name} ||= "__ANON__";
151 Moose::Meta::TypeConstraint::Class->new(%options);
154 sub create_role_type_constraint {
155 my ( $role, $options ) = @_;
157 # too early for this check
158 #find_type_constraint("ClassName")->check($class)
159 # || __PACKAGE__->_throw_error("Can't create a class type constraint because '$class' is not a class name");
167 $options{name} ||= "__ANON__";
169 Moose::Meta::TypeConstraint::Role->new(%options);
172 sub find_or_create_type_constraint {
173 my ( $type_constraint_name, $options_for_anon_type ) = @_;
176 = find_or_parse_type_constraint($type_constraint_name) ) {
179 elsif ( defined $options_for_anon_type ) {
182 # if there is no $options_for_anon_type
183 # specified, then we assume they don't
184 # want to create one, and return nothing.
186 # otherwise assume that we should create
187 # an ANON type with the $options_for_anon_type
188 # options which can be passed in. It should
189 # be noted that these don't get registered
190 # so we need to return it.
192 return Moose::Meta::TypeConstraint->new(
194 %{$options_for_anon_type}
201 sub find_or_create_isa_type_constraint {
202 my $type_constraint_name = shift;
203 find_or_parse_type_constraint($type_constraint_name)
204 || create_class_type_constraint($type_constraint_name);
207 sub find_or_create_does_type_constraint {
208 my $type_constraint_name = shift;
209 find_or_parse_type_constraint($type_constraint_name)
210 || create_role_type_constraint($type_constraint_name);
213 sub find_or_parse_type_constraint {
214 my $type_constraint_name = normalize_type_constraint_name(shift);
217 if ( $constraint = find_type_constraint($type_constraint_name) ) {
220 elsif ( _detect_type_constraint_union($type_constraint_name) ) {
221 $constraint = create_type_constraint_union($type_constraint_name);
223 elsif ( _detect_parameterized_type_constraint($type_constraint_name) ) {
225 = create_parameterized_type_constraint($type_constraint_name);
231 $REGISTRY->add_type_constraint($constraint);
235 sub normalize_type_constraint_name {
236 my $type_constraint_name = shift;
237 $type_constraint_name =~ s/\s//g;
238 return $type_constraint_name;
244 local $Carp::CarpLevel = $Carp::CarpLevel + 1;
245 Carp::confess($error);
248 ## --------------------------------------------------------
249 ## exported functions ...
250 ## --------------------------------------------------------
252 sub find_type_constraint {
255 if ( blessed $type and $type->isa("Moose::Meta::TypeConstraint") ) {
259 return unless $REGISTRY->has_type_constraint($type);
260 return $REGISTRY->get_type_constraint($type);
264 sub register_type_constraint {
265 my $constraint = shift;
266 __PACKAGE__->_throw_error("can't register an unnamed type constraint")
267 unless defined $constraint->name;
268 $REGISTRY->add_type_constraint($constraint);
276 # back-compat version, called without sugar
277 if ( !any { ( reftype($_) || '' ) eq 'HASH' } @_ ) {
278 return _create_type_constraint( $_[0], undef, $_[1] );
283 my %p = map { %{$_} } @_;
285 return _create_type_constraint(
286 $name, undef, $p{where}, $p{message},
293 # crazy back-compat code for being called without sugar ...
295 # subtype 'Parent', sub { where };
296 if ( scalar @_ == 2 && ( reftype( $_[1] ) || '' ) eq 'CODE' ) {
297 return _create_type_constraint( undef, @_ );
300 # subtype 'Parent', sub { where }, sub { message };
301 # subtype 'Parent', sub { where }, sub { message }, sub { optimized };
302 if ( scalar @_ >= 3 && all { ( reftype($_) || '' ) eq 'CODE' }
304 return _create_type_constraint( undef, @_ );
307 # subtype 'Name', 'Parent', ...
308 if ( scalar @_ >= 2 && all { !ref } @_[ 0, 1 ] ) {
309 return _create_type_constraint(@_);
312 if ( @_ == 1 && !ref $_[0] ) {
313 __PACKAGE__->_throw_error(
314 'A subtype cannot consist solely of a name, it must have a parent'
318 # The blessed check is mostly to accommodate MooseX::Types, which
319 # uses an object which overloads stringification as a type name.
320 my $name = ref $_[0] && !blessed $_[0] ? undef : shift;
322 my %p = map { %{$_} } @_;
324 # subtype Str => where { ... };
325 if ( !exists $p{as} ) {
330 return _create_type_constraint(
331 $name, $p{as}, $p{where}, $p{message},
337 register_type_constraint(
338 create_class_type_constraint(
340 ( defined( $_[1] ) ? $_[1] : () ),
345 sub role_type ($;$) {
346 register_type_constraint(
347 create_role_type_constraint(
349 ( defined( $_[1] ) ? $_[1] : () ),
355 my ($type_parameter) = @_;
357 register_type_constraint(
358 $REGISTRY->get_type_constraint('Maybe')->parameterize($type_parameter)
363 my ( $type_name, @methods ) = @_;
364 if ( ref $type_name eq 'ARRAY' && !@methods ) {
365 @methods = @$type_name;
368 if ( @methods == 1 && ref $methods[0] eq 'ARRAY' ) {
369 @methods = @{ $methods[0] };
372 register_type_constraint(
373 create_duck_type_constraint(
381 my ( $type_name, @coercion_map ) = @_;
382 _install_type_coercions( $type_name, \@coercion_map );
385 # The trick of returning @_ lets us avoid having to specify a
386 # prototype. Perl will parse this:
394 # subtype( 'Foo', as( 'Str', where { ... } ) );
396 # If as() returns all it's extra arguments, this just works, and
397 # preserves backwards compatibility.
398 sub as { { as => shift }, @_ }
399 sub where (&) { { where => $_[0] } }
400 sub message (&) { { message => $_[0] } }
401 sub optimize_as (&) { { optimize_as => $_[0] } }
404 sub via (&) { $_[0] }
407 my ( $type_name, @values ) = @_;
410 # if only an array-ref is passed then
411 # you get an anon-enum
413 if ( ref $type_name eq 'ARRAY' && !@values ) {
414 @values = @$type_name;
417 if ( @values == 1 && ref $values[0] eq 'ARRAY' ) {
418 @values = @{ $values[0] };
420 ( scalar @values >= 2 )
421 || __PACKAGE__->_throw_error(
422 "You must have at least two values to enumerate through");
423 my %valid = map { $_ => 1 } @values;
425 register_type_constraint(
426 create_enum_type_constraint(
433 sub create_enum_type_constraint {
434 my ( $type_name, $values ) = @_;
436 Moose::Meta::TypeConstraint::Enum->new(
437 name => $type_name || '__ANON__',
442 sub create_duck_type_constraint {
443 my ( $type_name, $methods ) = @_;
445 Moose::Meta::TypeConstraint::DuckType->new(
446 name => $type_name || '__ANON__',
452 my ($to_match, @cases) = @_;
454 if (@cases % 2 != 0) {
455 $default = pop @cases;
456 (ref $default eq 'CODE')
457 || __PACKAGE__->_throw_error("Default case must be a CODE ref, not $default");
460 my ($type, $action) = splice @cases, 0, 2;
462 unless (blessed $type && $type->isa('Moose::Meta::TypeConstraint')) {
463 $type = find_or_parse_type_constraint($type)
464 || __PACKAGE__->_throw_error("Cannot find or parse the type '$type'")
467 (ref $action eq 'CODE')
468 || __PACKAGE__->_throw_error("Match action must be a CODE ref, not $action");
470 if ($type->check($to_match)) {
471 local $_ = $to_match;
472 return $action->($to_match);
476 || __PACKAGE__->_throw_error("No cases matched for $to_match");
478 local $_ = $to_match;
479 return $default->($to_match);
484 ## --------------------------------------------------------
485 ## desugaring functions ...
486 ## --------------------------------------------------------
488 sub _create_type_constraint ($$$;$$) {
493 my $optimized = shift;
495 my $pkg_defined_in = scalar( caller(1) );
497 if ( defined $name ) {
498 my $type = $REGISTRY->get_type_constraint($name);
500 ( $type->_package_defined_in eq $pkg_defined_in )
502 "The type constraint '$name' has already been created in "
503 . $type->_package_defined_in
504 . " and cannot be created again in "
508 $name =~ /^[\w:\.]+$/
509 or die qq{$name contains invalid characters for a type name.}
510 . qq{ Names can contain alphanumeric character, ":", and "."\n};
515 package_defined_in => $pkg_defined_in,
517 ( $check ? ( constraint => $check ) : () ),
518 ( $message ? ( message => $message ) : () ),
519 ( $optimized ? ( optimized => $optimized ) : () ),
528 : find_or_create_isa_type_constraint($parent)
530 $constraint = $parent->create_child_type(%opts);
533 $constraint = Moose::Meta::TypeConstraint->new(%opts);
536 $REGISTRY->add_type_constraint($constraint)
542 sub _install_type_coercions ($$) {
543 my ( $type_name, $coercion_map ) = @_;
544 my $type = find_type_constraint($type_name);
546 || __PACKAGE__->_throw_error(
547 "Cannot find type '$type_name', perhaps you forgot to load it");
548 if ( $type->has_coercion ) {
549 $type->coercion->add_type_coercions(@$coercion_map);
552 my $type_coercion = Moose::Meta::TypeCoercion->new(
553 type_coercion_map => $coercion_map,
554 type_constraint => $type
556 $type->coercion($type_coercion);
560 ## --------------------------------------------------------
561 ## type notation parsing ...
562 ## --------------------------------------------------------
566 # All I have to say is mugwump++ cause I know
567 # do not even have enough regexp-fu to be able
568 # to have written this (I can only barely
569 # understand it as it is)
574 my $valid_chars = qr{[\w:\.]};
575 my $type_atom = qr{ $valid_chars+ };
579 my $type = qr{ $valid_chars+ (?: \[ \s* (??{$any}) \s* \] )? }x;
580 my $type_capture_parts
581 = qr{ ($valid_chars+) (?: \[ \s* ((??{$any})) \s* \] )? }x;
582 my $type_with_parameter
583 = qr{ $valid_chars+ \[ \s* (??{$any}) \s* \] }x;
585 my $op_union = qr{ \s* \| \s* }x;
586 my $union = qr{ $type (?: $op_union $type )+ }x;
588 $any = qr{ $type | $union }x;
590 sub _parse_parameterized_type_constraint {
591 { no warnings 'void'; $any; } # force capture of interpolated lexical
592 $_[0] =~ m{ $type_capture_parts }x;
596 sub _detect_parameterized_type_constraint {
597 { no warnings 'void'; $any; } # force capture of interpolated lexical
598 $_[0] =~ m{ ^ $type_with_parameter $ }x;
601 sub _parse_type_constraint_union {
602 { no warnings 'void'; $any; } # force capture of interpolated lexical
605 while ( $given =~ m{ \G (?: $op_union )? ($type) }gcx ) {
608 ( pos($given) eq length($given) )
609 || __PACKAGE__->_throw_error( "'$given' didn't parse (parse-pos="
617 sub _detect_type_constraint_union {
618 { no warnings 'void'; $any; } # force capture of interpolated lexical
619 $_[0] =~ m{^ $type $op_union $type ( $op_union .* )? $}x;
623 ## --------------------------------------------------------
624 # define some basic built-in types
625 ## --------------------------------------------------------
627 # By making these classes immutable before creating all the types we
628 # below, we avoid repeatedly calling the slow MOP-based accessors.
630 inline_constructor => 1,
631 constructor_name => "_new",
633 # these are Class::MOP accessors, so they need inlining
634 inline_accessors => 1
635 ) for grep { $_->is_mutable }
636 map { Class::MOP::class_of($_) }
638 Moose::Meta::TypeConstraint
639 Moose::Meta::TypeConstraint::Union
640 Moose::Meta::TypeConstraint::Parameterized
641 Moose::Meta::TypeConstraint::Parameterizable
642 Moose::Meta::TypeConstraint::Class
643 Moose::Meta::TypeConstraint::Role
644 Moose::Meta::TypeConstraint::Enum
645 Moose::Meta::TypeConstraint::DuckType
646 Moose::Meta::TypeConstraint::Registry
649 type 'Any' => where {1}; # meta-type including all
650 subtype 'Item' => as 'Any'; # base-type
652 subtype 'Undef' => as 'Item' => where { !defined($_) };
653 subtype 'Defined' => as 'Item' => where { defined($_) };
655 subtype 'Bool' => as 'Item' =>
656 where { !defined($_) || $_ eq "" || "$_" eq '1' || "$_" eq '0' };
658 subtype 'Value' => as 'Defined' => where { !ref($_) } =>
659 optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::Value;
661 subtype 'Ref' => as 'Defined' => where { ref($_) } =>
662 optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::Ref;
664 subtype 'Str' => as 'Value' => where { ref(\$_) eq 'SCALAR' } =>
665 optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::Str;
667 subtype 'Num' => as 'Str' =>
668 where { Scalar::Util::looks_like_number($_) } =>
669 optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::Num;
671 subtype 'Int' => as 'Num' => where { "$_" =~ /^-?[0-9]+$/ } =>
672 optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::Int;
674 subtype 'ScalarRef' => as 'Ref' => where { ref($_) eq 'SCALAR' } =>
676 \&Moose::Util::TypeConstraints::OptimizedConstraints::ScalarRef;
677 subtype 'CodeRef' => as 'Ref' => where { ref($_) eq 'CODE' } =>
678 optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::CodeRef;
679 subtype 'RegexpRef' => as 'Ref' => where { ref($_) eq 'Regexp' } =>
681 \&Moose::Util::TypeConstraints::OptimizedConstraints::RegexpRef;
682 subtype 'GlobRef' => as 'Ref' => where { ref($_) eq 'GLOB' } =>
683 optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::GlobRef;
686 # scalar filehandles are GLOB refs,
687 # but a GLOB ref is not always a filehandle
688 subtype 'FileHandle' => as 'GlobRef' => where {
689 Scalar::Util::openhandle($_) || ( blessed($_) && $_->isa("IO::Handle") );
691 \&Moose::Util::TypeConstraints::OptimizedConstraints::FileHandle;
694 # blessed(qr/.../) returns true,.. how odd
695 subtype 'Object' => as 'Ref' =>
696 where { blessed($_) && blessed($_) ne 'Regexp' } =>
697 optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::Object;
699 # This type is deprecated.
700 subtype 'Role' => as 'Object' => where { $_->can('does') } =>
701 optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::Role;
703 my $_class_name_checker = sub { };
705 subtype 'ClassName' => as 'Str' =>
706 where { Class::MOP::is_class_loaded($_) } => optimize_as
707 \&Moose::Util::TypeConstraints::OptimizedConstraints::ClassName;
709 subtype 'RoleName' => as 'ClassName' => where {
710 (Class::MOP::class_of($_) || return)->isa('Moose::Meta::Role');
712 \&Moose::Util::TypeConstraints::OptimizedConstraints::RoleName;
714 ## --------------------------------------------------------
715 # parameterizable types ...
717 $REGISTRY->add_type_constraint(
718 Moose::Meta::TypeConstraint::Parameterizable->new(
720 package_defined_in => __PACKAGE__,
721 parent => find_type_constraint('Ref'),
722 constraint => sub { ref($_) eq 'ARRAY' },
724 \&Moose::Util::TypeConstraints::OptimizedConstraints::ArrayRef,
725 constraint_generator => sub {
726 my $type_parameter = shift;
727 my $check = $type_parameter->_compiled_type_constraint;
729 foreach my $x (@$_) {
730 ( $check->($x) ) || return;
738 $REGISTRY->add_type_constraint(
739 Moose::Meta::TypeConstraint::Parameterizable->new(
741 package_defined_in => __PACKAGE__,
742 parent => find_type_constraint('Ref'),
743 constraint => sub { ref($_) eq 'HASH' },
745 \&Moose::Util::TypeConstraints::OptimizedConstraints::HashRef,
746 constraint_generator => sub {
747 my $type_parameter = shift;
748 my $check = $type_parameter->_compiled_type_constraint;
750 foreach my $x ( values %$_ ) {
751 ( $check->($x) ) || return;
759 $REGISTRY->add_type_constraint(
760 Moose::Meta::TypeConstraint::Parameterizable->new(
762 package_defined_in => __PACKAGE__,
763 parent => find_type_constraint('Item'),
764 constraint => sub {1},
765 constraint_generator => sub {
766 my $type_parameter = shift;
767 my $check = $type_parameter->_compiled_type_constraint;
769 return 1 if not( defined($_) ) || $check->($_);
776 my @PARAMETERIZABLE_TYPES
777 = map { $REGISTRY->get_type_constraint($_) } qw[ArrayRef HashRef Maybe];
779 sub get_all_parameterizable_types {@PARAMETERIZABLE_TYPES}
781 sub add_parameterizable_type {
784 && $type->isa('Moose::Meta::TypeConstraint::Parameterizable') )
785 || __PACKAGE__->_throw_error(
786 "Type must be a Moose::Meta::TypeConstraint::Parameterizable not $type"
788 push @PARAMETERIZABLE_TYPES => $type;
791 ## --------------------------------------------------------
792 # end of built-in types ...
793 ## --------------------------------------------------------
796 my @BUILTINS = list_all_type_constraints();
797 sub list_all_builtin_type_constraints {@BUILTINS}
804 goto &Moose::throw_error;
815 Moose::Util::TypeConstraints - Type constraint system for Moose
819 use Moose::Util::TypeConstraints;
825 subtype 'NaturalLessThanTen'
828 => message { "This number ($_) is not less than ten!" };
834 enum 'RGBColors' => qw(red green blue);
836 no Moose::Util::TypeConstraints;
840 This module provides Moose with the ability to create custom type
841 constraints to be used in attribute definition.
843 =head2 Important Caveat
845 This is B<NOT> a type system for Perl 5. These are type constraints,
846 and they are not used by Moose unless you tell it to. No type
847 inference is performed, expressions are not typed, etc. etc. etc.
849 A type constraint is at heart a small "check if a value is valid"
850 function. A constraint can be associated with an attribute. This
851 simplifies parameter validation, and makes your code clearer to read,
852 because you can refer to constraints by name.
854 =head2 Slightly Less Important Caveat
856 It is B<always> a good idea to quote your type names.
858 This prevents Perl from trying to execute the call as an indirect
859 object call. This can be an issue when you have a subtype with the
860 same name as a valid class.
864 subtype DateTime => as Object => where { $_->isa('DateTime') };
866 will I<just work>, while this:
869 subtype DateTime => as Object => where { $_->isa('DateTime') };
871 will fail silently and cause many headaches. The simple way to solve
872 this, as well as future proof your subtypes from classes which have
873 yet to have been created, is to quote the type name:
876 subtype 'DateTime' => as 'Object' => where { $_->isa('DateTime') };
878 =head2 Default Type Constraints
880 This module also provides a simple hierarchy for Perl 5 types, here is
881 that hierarchy represented visually.
905 B<NOTE:> Any type followed by a type parameter C<[`a]> can be
906 parameterized, this means you can say:
908 ArrayRef[Int] # an array of integers
909 HashRef[CodeRef] # a hash of str to CODE ref mappings
910 Maybe[Str] # value may be a string, may be undefined
912 If Moose finds a name in brackets that it does not recognize as an
913 existing type, it assumes that this is a class name, for example
914 C<ArrayRef[DateTime]>.
916 B<NOTE:> Unless you parameterize a type, then it is invalid to include
917 the square brackets. I.e. C<ArrayRef[]> will be treated as a new type
918 name, I<not> as a parameterization of C<ArrayRef>.
920 B<NOTE:> The C<Undef> type constraint for the most part works
921 correctly now, but edge cases may still exist, please use it
924 B<NOTE:> The C<ClassName> type constraint does a complex package
925 existence check. This means that your class B<must> be loaded for this
926 type constraint to pass.
928 B<NOTE:> The C<RoleName> constraint checks a string is a I<package
929 name> which is a role, like C<'MyApp::Role::Comparable'>.
931 =head2 Type Constraint Naming
933 Type name declared via this module can only contain alphanumeric
934 characters, colons (:), and periods (.).
936 Since the types created by this module are global, it is suggested
937 that you namespace your types just as you would namespace your
938 modules. So instead of creating a I<Color> type for your
939 B<My::Graphics> module, you would call the type
940 I<My::Graphics::Types::Color> instead.
942 =head2 Use with Other Constraint Modules
944 This module can play nicely with other constraint modules with some
945 slight tweaking. The C<where> clause in types is expected to be a
946 C<CODE> reference which checks it's first argument and returns a
947 boolean. Since most constraint modules work in a similar way, it
948 should be simple to adapt them to work with Moose.
950 For instance, this is how you could use it with
951 L<Declare::Constraints::Simple> to declare a completely new type.
953 type 'HashOfArrayOfObjects',
957 -values => IsArrayRef(IsObject)
961 For more examples see the F<t/200_examples/004_example_w_DCS.t> test
964 Here is an example of using L<Test::Deep> and it's non-test
965 related C<eq_deeply> function.
967 type 'ArrayOfHashOfBarsAndRandomNumbers'
970 array_each(subhashof({
972 random_number => ignore()
976 For a complete example see the
977 F<t/200_examples/005_example_w_TestDeep.t> test file.
981 =head2 Type Constraint Constructors
983 The following functions are used to create type constraints. They
984 will also register the type constraints your create in a global
985 registry that is used to look types up by name.
987 See the L<SYNOPSIS> for an example of how to use these.
991 =item B<< subtype 'Name' => as 'Parent' => where { } ... >>
993 This creates a named subtype.
995 If you provide a parent that Moose does not recognize, it will
996 automatically create a new class type constraint for this name.
998 When creating a named type, the C<subtype> function should either be
999 called with the sugar helpers (C<where>, C<message>, etc), or with a
1000 name and a hashref of parameters:
1002 subtype( 'Foo', { where => ..., message => ... } );
1004 The valid hashref keys are C<as> (the parent), C<where>, C<message>,
1007 =item B<< subtype as 'Parent' => where { } ... >>
1009 This creates an unnamed subtype and will return the type
1010 constraint meta-object, which will be an instance of
1011 L<Moose::Meta::TypeConstraint>.
1013 When creating an anonymous type, the C<subtype> function should either
1014 be called with the sugar helpers (C<where>, C<message>, etc), or with
1015 just a hashref of parameters:
1017 subtype( { where => ..., message => ... } );
1019 =item B<class_type ($class, ?$options)>
1021 Creates a new subtype of C<Object> with the name C<$class> and the
1022 metaclass L<Moose::Meta::TypeConstraint::Class>.
1024 =item B<role_type ($role, ?$options)>
1026 Creates a C<Role> type constraint with the name C<$role> and the
1027 metaclass L<Moose::Meta::TypeConstraint::Role>.
1029 =item B<maybe_type ($type)>
1031 Creates a type constraint for either C<undef> or something of the
1034 =item B<duck_type ($name, \@methods)>
1036 This will create a subtype of Object and test to make sure the value
1037 C<can()> do the methods in C<\@methods>.
1039 This is intended as an easy way to accept non-Moose objects that
1040 provide a certain interface. If you're using Moose classes, we
1041 recommend that you use a C<requires>-only Role instead.
1043 =item B<duck_type (\@methods)>
1045 If passed an ARRAY reference as the only parameter instead of the
1046 C<$name>, C<\@methods> pair, this will create an unnamed duck type.
1047 This can be used in an attribute definition like so:
1051 isa => duck_type( [qw( get_set )] ),
1054 =item B<enum ($name, \@values)>
1056 This will create a basic subtype for a given set of strings.
1057 The resulting constraint will be a subtype of C<Str> and
1058 will match any of the items in C<\@values>. It is case sensitive.
1059 See the L<SYNOPSIS> for a simple example.
1061 B<NOTE:> This is not a true proper enum type, it is simply
1062 a convenient constraint builder.
1064 =item B<enum (\@values)>
1066 If passed an ARRAY reference as the only parameter instead of the
1067 C<$name>, C<\@values> pair, this will create an unnamed enum. This
1068 can then be used in an attribute definition like so:
1070 has 'sort_order' => (
1072 isa => enum([qw[ ascending descending ]]),
1075 =item B<as 'Parent'>
1077 This is just sugar for the type constraint construction syntax.
1079 It takes a single argument, which is the name of a parent type.
1081 =item B<where { ... }>
1083 This is just sugar for the type constraint construction syntax.
1085 It takes a subroutine reference as an argument. When the type
1086 constraint is tested, the reference is run with the value to be tested
1087 in C<$_>. This reference should return true or false to indicate
1088 whether or not the constraint check passed.
1090 =item B<message { ... }>
1092 This is just sugar for the type constraint construction syntax.
1094 It takes a subroutine reference as an argument. When the type
1095 constraint fails, then the code block is run with the value provided
1096 in C<$_>. This reference should return a string, which will be used in
1097 the text of the exception thrown.
1099 =item B<optimize_as { ... }>
1101 This can be used to define a "hand optimized" version of your
1102 type constraint which can be used to avoid traversing a subtype
1103 constraint hierarchy.
1105 B<NOTE:> You should only use this if you know what you are doing,
1106 all the built in types use this, so your subtypes (assuming they
1107 are shallow) will not likely need to use this.
1109 =item B<< type 'Name' => where { } ... >>
1111 This creates a base type, which has no parent.
1113 The C<type> function should either be called with the sugar helpers
1114 (C<where>, C<message>, etc), or with a name and a hashref of
1117 type( 'Foo', { where => ..., message => ... } );
1119 The valid hashref keys are C<where>, C<message>, and C<optimize_as>.
1123 =head2 Type Constraint Utilities
1127 =item B<< match_on_type $value => ( $type => \&action, ... ?\&default ) >>
1129 This is a utility function for doing simple type based dispatching similar to
1130 match/case in O'Caml and case/of in Haskell. It is not as featureful as those
1131 languages, nor does not it support any kind of automatic destructuring
1132 bind. Here is a simple Perl pretty printer dispatching over the core Moose
1137 match_on_type $x => (
1142 join ", " => map { $_ . ' => ' . ppprint( $hash->{$_} ) }
1148 '[ ' . ( join ", " => map { ppprint($_) } @$array ) . ' ]';
1150 CodeRef => sub {'sub { ... }'},
1151 RegexpRef => sub { 'qr/' . $_ . '/' },
1152 GlobRef => sub { '*' . B::svref_2object($_)->NAME },
1153 Object => sub { $_->can('to_string') ? $_->to_string : $_ },
1154 ScalarRef => sub { '\\' . ppprint( ${$_} ) },
1156 Str => sub { '"' . $_ . '"' },
1157 Undef => sub {'undef'},
1158 => sub { die "I don't know what $_ is" }
1162 Or a simple JSON serializer:
1166 match_on_type $x => (
1172 map { '"' . $_ . '" : ' . to_json( $hash->{$_} ) }
1178 '[ ' . ( join ", " => map { to_json($_) } @$array ) . ' ]';
1181 Str => sub { '"' . $_ . '"' },
1182 Undef => sub {'null'},
1183 => sub { die "$_ is not acceptable json type" }
1187 The matcher is done by mapping a C<$type> to an C<\&action>. The C<$type> can
1188 be either a string type or a L<Moose::Meta::TypeConstraint> object, and
1189 C<\&action> is a subroutine reference. This function will dispatch on the
1190 first match for C<$value>. It is possible to have a catch-all by providing an
1191 additional subroutine reference as the final argument to C<match_on_type>.
1195 =head2 Type Coercion Constructors
1197 You can define coercions for type constraints, which allow you to
1198 automatically transform values to something valid for the type
1199 constraint. If you ask your accessor to coerce, then Moose will run
1200 the type-coercion code first, followed by the type constraint
1201 check. This feature should be used carefully as it is very powerful
1202 and could easily take off a limb if you are not careful.
1204 See the L<SYNOPSIS> for an example of how to use these.
1208 =item B<< coerce 'Name' => from 'OtherName' => via { ... } >>
1210 This defines a coercion from one type to another. The C<Name> argument
1211 is the type you are coercing I<to>.
1213 =item B<from 'OtherName'>
1215 This is just sugar for the type coercion construction syntax.
1217 It takes a single type name (or type object), which is the type being
1220 =item B<via { ... }>
1222 This is just sugar for the type coercion construction syntax.
1224 It takes a subroutine reference. This reference will be called with
1225 the value to be coerced in C<$_>. It is expected to return a new value
1226 of the proper type for the coercion.
1230 =head2 Creating and Finding Type Constraints
1232 These are additional functions for creating and finding type
1233 constraints. Most of these functions are not available for
1234 importing. The ones that are importable as specified.
1238 =item B<find_type_constraint($type_name)>
1240 This function can be used to locate the L<Moose::Meta::TypeConstraint>
1241 object for a named type.
1243 This function is importable.
1245 =item B<register_type_constraint($type_object)>
1247 This function will register a L<Moose::Meta::TypeConstraint> with the
1248 global type registry.
1250 This function is importable.
1252 =item B<normalize_type_constraint_name($type_constraint_name)>
1254 This method takes a type constraint name and returns the normalized
1255 form. This removes any whitespace in the string.
1257 =item B<create_type_constraint_union($pipe_separated_types | @type_constraint_names)>
1259 This can take a union type specification like C<'Int|ArrayRef[Int]'>,
1260 or a list of names. It returns a new
1261 L<Moose::Meta::TypeConstraint::Union> object.
1263 =item B<create_parameterized_type_constraint($type_name)>
1265 Given a C<$type_name> in the form of C<'BaseType[ContainerType]'>,
1266 this will create a new L<Moose::Meta::TypeConstraint::Parameterized>
1267 object. The C<BaseType> must exist already exist as a parameterizable
1270 =item B<create_class_type_constraint($class, $options)>
1272 Given a class name this function will create a new
1273 L<Moose::Meta::TypeConstraint::Class> object for that class name.
1275 The C<$options> is a hash reference that will be passed to the
1276 L<Moose::Meta::TypeConstraint::Class> constructor (as a hash).
1278 =item B<create_role_type_constraint($role, $options)>
1280 Given a role name this function will create a new
1281 L<Moose::Meta::TypeConstraint::Role> object for that role name.
1283 The C<$options> is a hash reference that will be passed to the
1284 L<Moose::Meta::TypeConstraint::Role> constructor (as a hash).
1286 =item B<create_enum_type_constraint($name, $values)>
1288 Given a enum name this function will create a new
1289 L<Moose::Meta::TypeConstraint::Enum> object for that enum name.
1291 =item B<create_duck_type_constraint($name, $methods)>
1293 Given a duck type name this function will create a new
1294 L<Moose::Meta::TypeConstraint::DuckType> object for that enum name.
1296 =item B<find_or_parse_type_constraint($type_name)>
1298 Given a type name, this first attempts to find a matching constraint
1299 in the global registry.
1301 If the type name is a union or parameterized type, it will create a
1302 new object of the appropriate, but if given a "regular" type that does
1303 not yet exist, it simply returns false.
1305 When given a union or parameterized type, the member or base type must
1308 If it creates a new union or parameterized type, it will add it to the
1311 =item B<find_or_create_isa_type_constraint($type_name)>
1313 =item B<find_or_create_does_type_constraint($type_name)>
1315 These functions will first call C<find_or_parse_type_constraint>. If
1316 that function does not return a type, a new anonymous type object will
1319 The C<isa> variant will use C<create_class_type_constraint> and the
1320 C<does> variant will use C<create_role_type_constraint>.
1322 =item B<get_type_constraint_registry>
1324 Returns the L<Moose::Meta::TypeConstraint::Registry> object which
1325 keeps track of all type constraints.
1327 =item B<list_all_type_constraints>
1329 This will return a list of type constraint names in the global
1330 registry. You can then fetch the actual type object using
1331 C<find_type_constraint($type_name)>.
1333 =item B<list_all_builtin_type_constraints>
1335 This will return a list of builtin type constraints, meaning those
1336 which are defined in this module. See the L<Default Type Constraints>
1337 section for a complete list.
1339 =item B<export_type_constraints_as_functions>
1341 This will export all the current type constraints as functions into
1342 the caller's namespace (C<Int()>, C<Str()>, etc). Right now, this is
1343 mostly used for testing, but it might prove useful to others.
1345 =item B<get_all_parameterizable_types>
1347 This returns all the parameterizable types that have been registered,
1348 as a list of type objects.
1350 =item B<add_parameterizable_type($type)>
1352 Adds C<$type> to the list of parameterizable types
1358 All complex software has bugs lurking in it, and this module is no
1359 exception. If you find a bug please either email me, or add the bug
1364 Stevan Little E<lt>stevan@iinteractive.comE<gt>
1366 =head1 COPYRIGHT AND LICENSE
1368 Copyright 2006-2009 by Infinity Interactive, Inc.
1370 L<http://www.iinteractive.com>
1372 This library is free software; you can redistribute it and/or modify
1373 it under the same terms as Perl itself.