2 package Moose::Util::TypeConstraints;
8 use Scalar::Util 'blessed', 'reftype';
11 our $VERSION = '0.22';
12 our $AUTHORITY = 'cpan:STEVAN';
14 ## --------------------------------------------------------
15 # Prototyped subs must be predeclared because we have a
16 # circular dependency with Moose::Meta::Attribute et. al.
17 # so in case of us being use'd first the predeclaration
18 # ensures the prototypes are in scope when consumers are
21 # creation and location
22 sub find_type_constraint ($);
23 sub register_type_constraint ($);
24 sub find_or_create_type_constraint ($;$);
25 sub create_type_constraint_union (@);
26 sub create_parameterized_type_constraint ($);
27 sub create_class_type_constraint ($;$);
28 #sub create_class_type_constraint ($);
44 sub _create_type_constraint ($$$;$$);
45 sub _install_type_coercions ($$);
47 ## --------------------------------------------------------
49 use Moose::Meta::TypeConstraint;
50 use Moose::Meta::TypeConstraint::Union;
51 use Moose::Meta::TypeConstraint::Parameterized;
52 use Moose::Meta::TypeConstraint::Parameterizable;
53 use Moose::Meta::TypeCoercion;
54 use Moose::Meta::TypeCoercion::Union;
55 use Moose::Meta::TypeConstraint::Registry;
56 use Moose::Util::TypeConstraints::OptimizedConstraints;
59 type subtype class_type as where message optimize_as
63 register_type_constraint
66 Sub::Exporter::setup_exporter({
68 groups => { default => [':all'] }
74 # loop through the exports ...
75 foreach my $name (@exports) {
77 if (defined &{$class . '::' . $name}) {
78 my $keyword = \&{$class . '::' . $name};
80 # make sure it is from Moose
81 my ($pkg_name) = Class::MOP::get_code_info($keyword);
83 next if $pkg_name ne 'Moose::Util::TypeConstraints';
85 # and if it is from Moose then undef the slot
86 delete ${$class . '::'}{$name};
91 ## --------------------------------------------------------
92 ## type registry and some useful functions for it
93 ## --------------------------------------------------------
95 my $REGISTRY = Moose::Meta::TypeConstraint::Registry->new;
97 sub get_type_constraint_registry { $REGISTRY }
98 sub list_all_type_constraints { keys %{$REGISTRY->type_constraints} }
99 sub export_type_constraints_as_functions {
102 foreach my $constraint (keys %{$REGISTRY->type_constraints}) {
103 my $tc = $REGISTRY->get_type_constraint($constraint)->_compiled_type_constraint;
104 *{"${pkg}::${constraint}"} = sub { $tc->($_[0]) ? 1 : undef };
108 sub create_type_constraint_union (@) {
109 my @type_constraint_names;
111 if (scalar @_ == 1 && _detect_type_constraint_union($_[0])) {
112 @type_constraint_names = _parse_type_constraint_union($_[0]);
115 @type_constraint_names = @_;
118 (scalar @type_constraint_names >= 2)
119 || confess "You must pass in at least 2 type names to make a union";
121 ($REGISTRY->has_type_constraint($_))
122 || confess "Could not locate type constraint ($_) for the union"
123 foreach @type_constraint_names;
125 return Moose::Meta::TypeConstraint::Union->new(
126 type_constraints => [
128 $REGISTRY->get_type_constraint($_)
129 } @type_constraint_names
134 sub create_parameterized_type_constraint ($) {
135 my $type_constraint_name = shift;
137 my ($base_type, $type_parameter) = _parse_parameterized_type_constraint($type_constraint_name);
139 (defined $base_type && defined $type_parameter)
140 || confess "Could not parse type name ($type_constraint_name) correctly";
142 ($REGISTRY->has_type_constraint($base_type))
143 || confess "Could not locate the base type ($base_type)";
145 return Moose::Meta::TypeConstraint::Parameterized->new(
146 name => $type_constraint_name,
147 parent => $REGISTRY->get_type_constraint($base_type),
148 type_parameter => find_or_create_type_constraint(
150 parent => $REGISTRY->get_type_constraint('Object'),
151 constraint => sub { $_[0]->isa($type_parameter) }
157 #should we also support optimized checks?
158 sub create_class_type_constraint ($;$) {
160 # too early for this check
161 #find_type_constraint("ClassName")->check($class)
162 # || confess "Can't create a class type constraint because '$class' is not a class name";
165 $message = $_[0]->{message} if exists $_[0]->{message};
168 Moose::Meta::TypeConstraint::Class->new(
170 ($message ? (message => $message) : ())
174 sub find_or_create_type_constraint ($;$) {
175 my ($type_constraint_name, $options_for_anon_type) = @_;
177 return $REGISTRY->get_type_constraint($type_constraint_name)
178 if $REGISTRY->has_type_constraint($type_constraint_name);
182 if (_detect_type_constraint_union($type_constraint_name)) {
183 $constraint = create_type_constraint_union($type_constraint_name);
185 elsif (_detect_parameterized_type_constraint($type_constraint_name)) {
186 $constraint = create_parameterized_type_constraint($type_constraint_name);
190 # if there is no $options_for_anon_type
191 # specified, then we assume they don't
192 # want to create one, and return nothing.
193 return unless defined $options_for_anon_type;
196 # otherwise assume that we should create
197 # an ANON type with the $options_for_anon_type
198 # options which can be passed in. It should
199 # be noted that these don't get registered
200 # so we need to return it.
202 return Moose::Meta::TypeConstraint->new(
204 %{$options_for_anon_type}
208 $REGISTRY->add_type_constraint($constraint);
212 ## --------------------------------------------------------
213 ## exported functions ...
214 ## --------------------------------------------------------
216 sub find_type_constraint ($) { $REGISTRY->get_type_constraint(@_) }
218 sub register_type_constraint ($) {
219 my $constraint = shift;
220 confess "can't register an unnamed type constraint" unless defined $constraint->name;
221 $REGISTRY->add_type_constraint($constraint);
227 splice(@_, 1, 0, undef);
228 goto &_create_type_constraint;
231 sub subtype ($$;$$$) {
233 # this adds an undef for the name
234 # if this is an anon-subtype:
235 # subtype(Num => where { $_ % 2 == 0 }) # anon 'even' subtype
236 # but if the last arg is not a code
237 # ref then it is a subtype alias:
238 # subtype(MyNumbers => as Num); # now MyNumbers is the same as Num
239 # ... yeah I know it's ugly code
241 unshift @_ => undef if scalar @_ <= 2 && (reftype($_[1]) || '') eq 'CODE';
242 goto &_create_type_constraint;
245 sub class_type ($;$) {
246 register_type_constraint(
247 create_class_type_constraint(
249 ( defined($_[1]) ? $_[1] : () ),
255 my ($type_name, @coercion_map) = @_;
256 _install_type_coercions($type_name, \@coercion_map);
260 sub from ($) { $_[0] }
261 sub where (&) { $_[0] }
262 sub via (&) { $_[0] }
264 sub message (&) { +{ message => $_[0] } }
265 sub optimize_as (&) { +{ optimized => $_[0] } }
268 my ($type_name, @values) = @_;
270 # if only an array-ref is passed then
271 # you get an anon-enum
273 if (ref $type_name eq 'ARRAY' && !@values) {
274 @values = @$type_name;
277 (scalar @values >= 2)
278 || confess "You must have at least two values to enumerate through";
279 my %valid = map { $_ => 1 } @values;
280 _create_type_constraint(
287 ## --------------------------------------------------------
288 ## desugaring functions ...
289 ## --------------------------------------------------------
291 sub _create_type_constraint ($$$;$$) {
296 my ($message, $optimized);
298 $message = $_->{message} if exists $_->{message};
299 $optimized = $_->{optimized} if exists $_->{optimized};
302 my $pkg_defined_in = scalar(caller(0));
305 my $type = $REGISTRY->get_type_constraint($name);
307 ($type->_package_defined_in eq $pkg_defined_in)
308 || confess ("The type constraint '$name' has already been created in "
309 . $type->_package_defined_in . " and cannot be created again in "
314 $parent = find_or_create_type_constraint($parent) if defined $parent;
316 my $constraint = Moose::Meta::TypeConstraint->new(
317 name => $name || '__ANON__',
318 package_defined_in => $pkg_defined_in,
320 ($parent ? (parent => $parent ) : ()),
321 ($check ? (constraint => $check) : ()),
322 ($message ? (message => $message) : ()),
323 ($optimized ? (optimized => $optimized) : ()),
327 # if we have a type constraint union, and no
328 # type check, this means we are just aliasing
329 # the union constraint, which means we need to
330 # handle this differently.
332 if (not(defined $check)
333 && $parent->isa('Moose::Meta::TypeConstraint::Union')
334 && $parent->has_coercion
336 $constraint->coercion(Moose::Meta::TypeCoercion::Union->new(
337 type_constraint => $parent
341 $REGISTRY->add_type_constraint($constraint)
347 sub _install_type_coercions ($$) {
348 my ($type_name, $coercion_map) = @_;
349 my $type = $REGISTRY->get_type_constraint($type_name);
351 || confess "Cannot find type '$type_name', perhaps you forgot to load it.";
352 if ($type->has_coercion) {
353 $type->coercion->add_type_coercions(@$coercion_map);
356 my $type_coercion = Moose::Meta::TypeCoercion->new(
357 type_coercion_map => $coercion_map,
358 type_constraint => $type
360 $type->coercion($type_coercion);
364 ## --------------------------------------------------------
365 ## type notation parsing ...
366 ## --------------------------------------------------------
369 # All I have to say is mugwump++ cause I know
370 # do not even have enough regexp-fu to be able
371 # to have written this (I can only barely
372 # understand it as it is)
377 my $valid_chars = qr{[\w:]};
378 my $type_atom = qr{ $valid_chars+ };
380 my $type = qr{ $valid_chars+ (?: \[ (??{$any}) \] )? }x;
381 my $type_capture_parts = qr{ ($valid_chars+) (?: \[ ((??{$any})) \] )? }x;
382 my $type_with_parameter = qr{ $valid_chars+ \[ (??{$any}) \] }x;
384 my $op_union = qr{ \s* \| \s* }x;
385 my $union = qr{ $type (?: $op_union $type )+ }x;
387 our $any = qr{ $type | $union }x;
389 sub _parse_parameterized_type_constraint {
390 $_[0] =~ m{ $type_capture_parts }x;
394 sub _detect_parameterized_type_constraint {
395 $_[0] =~ m{ ^ $type_with_parameter $ }x;
398 sub _parse_type_constraint_union {
401 while ( $given =~ m{ \G (?: $op_union )? ($type) }gcx ) {
404 (pos($given) eq length($given))
405 || confess "'$given' didn't parse (parse-pos="
413 sub _detect_type_constraint_union {
414 $_[0] =~ m{^ $type $op_union $type ( $op_union .* )? $}x;
418 ## --------------------------------------------------------
419 # define some basic built-in types
420 ## --------------------------------------------------------
422 type 'Any' => where { 1 }; # meta-type including all
423 type 'Item' => where { 1 }; # base-type
425 subtype 'Undef' => as 'Item' => where { !defined($_) };
426 subtype 'Defined' => as 'Item' => where { defined($_) };
430 => where { !defined($_) || $_ eq "" || "$_" eq '1' || "$_" eq '0' };
434 => where { !ref($_) }
435 => optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::Value;
440 => optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::Ref;
445 => optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::Str;
449 => where { Scalar::Util::looks_like_number($_) }
450 => optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::Num;
454 => where { "$_" =~ /^-?[0-9]+$/ }
455 => optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::Int;
457 subtype 'ScalarRef' => as 'Ref' => where { ref($_) eq 'SCALAR' } => optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::ScalarRef;
458 subtype 'CodeRef' => as 'Ref' => where { ref($_) eq 'CODE' } => optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::CodeRef;
459 subtype 'RegexpRef' => as 'Ref' => where { ref($_) eq 'Regexp' } => optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::RegexpRef;
460 subtype 'GlobRef' => as 'Ref' => where { ref($_) eq 'GLOB' } => optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::GlobRef;
463 # scalar filehandles are GLOB refs,
464 # but a GLOB ref is not always a filehandle
467 => where { Scalar::Util::openhandle($_) || ( blessed($_) && $_->isa("IO::Handle") ) }
468 => optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::FileHandle;
471 # blessed(qr/.../) returns true,.. how odd
474 => where { blessed($_) && blessed($_) ne 'Regexp' }
475 => optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::Object;
479 => where { $_->can('does') }
480 => optimize_as \&Moose::Util::TypeConstraints::OptimizedConstraints::Role;
482 my $_class_name_checker = sub {
483 return if ref($_[0]);
484 return unless defined($_[0]) && length($_[0]);
486 # walk the symbol table tree to avoid autovififying
487 # \*{${main::}{"Foo::"}} == \*main::Foo::
490 foreach my $part (split('::', $_[0])) {
491 return unless exists ${$$pack}{"${part}::"};
492 $pack = \*{${$$pack}{"${part}::"}};
495 # check for $VERSION or @ISA
496 return 1 if exists ${$$pack}{VERSION}
497 && defined *{${$$pack}{VERSION}}{SCALAR};
498 return 1 if exists ${$$pack}{ISA}
499 && defined *{${$$pack}{ISA}}{ARRAY};
501 # check for any method
502 foreach ( keys %{$$pack} ) {
503 next if substr($_, -2, 2) eq '::';
504 return 1 if defined *{${$$pack}{$_}}{CODE};
513 => $_class_name_checker # where ...
514 => { optimize => $_class_name_checker };
516 ## --------------------------------------------------------
517 # parameterizable types ...
519 $REGISTRY->add_type_constraint(
520 Moose::Meta::TypeConstraint::Parameterizable->new(
522 package_defined_in => __PACKAGE__,
523 parent => find_type_constraint('Ref'),
524 constraint => sub { ref($_) eq 'ARRAY' },
525 optimized => \&Moose::Util::TypeConstraints::OptimizedConstraints::ArrayRef,
526 constraint_generator => sub {
527 my $type_parameter = shift;
529 foreach my $x (@$_) {
530 ($type_parameter->check($x)) || return
537 $REGISTRY->add_type_constraint(
538 Moose::Meta::TypeConstraint::Parameterizable->new(
540 package_defined_in => __PACKAGE__,
541 parent => find_type_constraint('Ref'),
542 constraint => sub { ref($_) eq 'HASH' },
543 optimized => \&Moose::Util::TypeConstraints::OptimizedConstraints::HashRef,
544 constraint_generator => sub {
545 my $type_parameter = shift;
547 foreach my $x (values %$_) {
548 ($type_parameter->check($x)) || return
555 $REGISTRY->add_type_constraint(
556 Moose::Meta::TypeConstraint::Parameterizable->new(
558 package_defined_in => __PACKAGE__,
559 parent => find_type_constraint('Item'),
560 constraint => sub { 1 },
561 constraint_generator => sub {
562 my $type_parameter = shift;
564 return 1 if not(defined($_)) || $type_parameter->check($_);
571 my @PARAMETERIZABLE_TYPES = map {
572 $REGISTRY->get_type_constraint($_)
573 } qw[ArrayRef HashRef Maybe];
575 sub get_all_parameterizable_types { @PARAMETERIZABLE_TYPES }
576 sub add_parameterizable_type {
578 (blessed $type && $type->isa('Moose::Meta::TypeConstraint::Parameterizable'))
579 || confess "Type must be a Moose::Meta::TypeConstraint::Parameterizable not $type";
580 push @PARAMETERIZABLE_TYPES => $type;
583 ## --------------------------------------------------------
584 # end of built-in types ...
585 ## --------------------------------------------------------
588 my @BUILTINS = list_all_type_constraints();
589 sub list_all_builtin_type_constraints { @BUILTINS }
600 Moose::Util::TypeConstraints - Type constraint system for Moose
604 use Moose::Util::TypeConstraints;
606 type 'Num' => where { Scalar::Util::looks_like_number($_) };
612 subtype 'NaturalLessThanTen'
615 => message { "This number ($_) is not less than ten!" };
621 enum 'RGBColors' => qw(red green blue);
625 This module provides Moose with the ability to create custom type
626 contraints to be used in attribute definition.
628 =head2 Important Caveat
630 This is B<NOT> a type system for Perl 5. These are type constraints,
631 and they are not used by Moose unless you tell it to. No type
632 inference is performed, expression are not typed, etc. etc. etc.
634 This is simply a means of creating small constraint functions which
635 can be used to simplify your own type-checking code.
637 =head2 Slightly Less Important Caveat
639 It is almost always a good idea to quote your type and subtype names.
640 This is to prevent perl from trying to execute the call as an indirect
641 object call. This issue only seems to come up when you have a subtype
642 the same name as a valid class, but when the issue does arise it tends
643 to be quite annoying to debug.
645 So for instance, this:
647 subtype DateTime => as Object => where { $_->isa('DateTime') };
649 will I<Just Work>, while this:
652 subtype DateTime => as Object => where { $_->isa('DateTime') };
654 will fail silently and cause many headaches. The simple way to solve
655 this, as well as future proof your subtypes from classes which have
656 yet to have been created yet, is to simply do this:
659 subtype 'DateTime' => as 'Object' => where { $_->isa('DateTime') };
661 =head2 Default Type Constraints
663 This module also provides a simple hierarchy for Perl 5 types, this
664 could probably use some work, but it works for me at the moment.
688 Suggestions for improvement are welcome.
690 B<NOTE:> Any type followed by a type parameter C<[`a]> can be
691 parameterized, this means you can say:
693 ArrayRef[Int] # an array of intergers
694 HashRef[CodeRef] # a hash of str to CODE ref mappings
695 Maybe[Str] # value may be a string, may be undefined
697 B<NOTE:> The C<Undef> type constraint for the most part works
698 correctly now, but edge cases may still exist, please use it
701 B<NOTE:> The C<ClassName> type constraint does a complex package
702 existence check. This means that your class B<must> be loaded for
703 this type constraint to pass. I know this is not ideal for all,
704 but it is a saner restriction than most others.
706 =head2 Use with Other Constraint Modules
708 This module should play fairly nicely with other constraint
709 modules with only some slight tweaking. The C<where> clause
710 in types is expected to be a C<CODE> reference which checks
711 it's first argument and returns a bool. Since most constraint
712 modules work in a similar way, it should be simple to adapt
713 them to work with Moose.
715 For instance, this is how you could use it with
716 L<Declare::Constraints::Simple> to declare a completely new type.
718 type 'HashOfArrayOfObjects'
721 -values => IsArrayRef( IsObject ));
723 For more examples see the F<t/204_example_w_DCS.t> test file.
725 Here is an example of using L<Test::Deep> and it's non-test
726 related C<eq_deeply> function.
728 type 'ArrayOfHashOfBarsAndRandomNumbers'
731 array_each(subhashof({
733 random_number => ignore()
737 For a complete example see the F<t/205_example_w_TestDeep.t>
742 =head2 Type Constraint Construction & Locating
746 =item B<create_type_constraint_union ($pipe_seperated_types | @type_constraint_names)>
748 Given string with C<$pipe_seperated_types> or a list of C<@type_constraint_names>,
749 this will return a L<Moose::Meta::TypeConstraint::Union> instance.
751 =item B<create_parameterized_type_constraint ($type_name)>
753 Given a C<$type_name> in the form of:
755 BaseType[ContainerType]
757 this will extract the base type and container type and build an instance of
758 L<Moose::Meta::TypeConstraint::Parameterized> for it.
760 =item B<create_class_type_constraint ($class, ?$message)>
762 Given a class name it will create a new L<Moose::Meta::TypeConstraint::Class>
763 object for that class name.
765 =item B<find_or_create_type_constraint ($type_name, ?$options_for_anon_type)>
767 This will attempt to find or create a type constraint given the a C<$type_name>.
768 If it cannot find it in the registry, it will see if it should be a union or
769 container type an create one if appropriate, and lastly if nothing can be
770 found or created that way, it will create an anon-type using the
771 C<$options_for_anon_type> HASH ref to populate it. If the C<$options_for_anon_type>
772 is not specified (it is C<undef>), then it will not create anything and simply
775 =item B<find_type_constraint ($type_name)>
777 This function can be used to locate a specific type constraint
778 meta-object, of the class L<Moose::Meta::TypeConstraint> or a
779 derivative. What you do with it from there is up to you :)
781 =item B<register_type_constraint ($type_object)>
783 This function will register a named type constraint with the type registry.
785 =item B<get_type_constraint_registry>
787 Fetch the L<Moose::Meta::TypeConstraint::Registry> object which
788 keeps track of all type constraints.
790 =item B<list_all_type_constraints>
792 This will return a list of type constraint names, you can then
793 fetch them using C<find_type_constraint ($type_name)> if you
796 =item B<list_all_builtin_type_constraints>
798 This will return a list of builtin type constraints, meaning,
799 those which are defined in this module. See the section
800 labeled L<Default Type Constraints> for a complete list.
802 =item B<export_type_constraints_as_functions>
804 This will export all the current type constraints as functions
805 into the caller's namespace. Right now, this is mostly used for
806 testing, but it might prove useful to others.
808 =item B<get_all_parameterizable_types>
810 This returns all the parameterizable types that have been registered.
812 =item B<add_parameterizable_type ($type)>
814 Adds C<$type> to the list of parameterizable types
818 =head2 Type Constraint Constructors
820 The following functions are used to create type constraints.
821 They will then register the type constraints in a global store
822 where Moose can get to them if it needs to.
824 See the L<SYNOPSIS> for an example of how to use these.
828 =item B<type ($name, $where_clause)>
830 This creates a base type, which has no parent.
832 =item B<subtype ($name, $parent, $where_clause, ?$message)>
834 This creates a named subtype.
836 =item B<subtype ($parent, $where_clause, ?$message)>
838 This creates an unnamed subtype and will return the type
839 constraint meta-object, which will be an instance of
840 L<Moose::Meta::TypeConstraint>.
842 =item B<class_type ($class, ?$message)>
844 Creates a type constraint with the name C<$class> and the metaclass
845 L<Moose::Meta::TypeConstraint::Class>.
847 =item B<enum ($name, @values)>
849 This will create a basic subtype for a given set of strings.
850 The resulting constraint will be a subtype of C<Str> and
851 will match any of the items in C<@values>. It is case sensitive.
852 See the L<SYNOPSIS> for a simple example.
854 B<NOTE:> This is not a true proper enum type, it is simple
855 a convient constraint builder.
857 =item B<enum (\@values)>
859 If passed an ARRAY reference instead of the C<$name>, C<@values> pair,
860 this will create an unnamed enum. This can then be used in an attribute
863 has 'sort_order' => (
865 isa => enum([qw[ ascending descending ]]),
870 This is just sugar for the type constraint construction syntax.
874 This is just sugar for the type constraint construction syntax.
878 This is just sugar for the type constraint construction syntax.
882 This can be used to define a "hand optimized" version of your
883 type constraint which can be used to avoid traversing a subtype
884 constraint heirarchy.
886 B<NOTE:> You should only use this if you know what you are doing,
887 all the built in types use this, so your subtypes (assuming they
888 are shallow) will not likely need to use this.
892 =head2 Type Coercion Constructors
894 Type constraints can also contain type coercions as well. If you
895 ask your accessor to coerce, then Moose will run the type-coercion
896 code first, followed by the type constraint check. This feature
897 should be used carefully as it is very powerful and could easily
898 take off a limb if you are not careful.
900 See the L<SYNOPSIS> for an example of how to use these.
908 This is just sugar for the type coercion construction syntax.
912 This is just sugar for the type coercion construction syntax.
916 =head2 Namespace Management
922 This will remove all the type constraint keywords from the
923 calling class namespace.
929 All complex software has bugs lurking in it, and this module is no
930 exception. If you find a bug please either email me, or add the bug
935 Stevan Little E<lt>stevan@iinteractive.comE<gt>
937 =head1 COPYRIGHT AND LICENSE
939 Copyright 2006-2008 by Infinity Interactive, Inc.
941 L<http://www.iinteractive.com>
943 This library is free software; you can redistribute it and/or modify
944 it under the same terms as Perl itself.