2 package Moose::Util::TypeConstraints;
8 use Scalar::Util 'blessed', 'reftype';
12 our $VERSION = '0.15';
13 our $AUTHORITY = 'cpan:STEVAN';
15 ## --------------------------------------------------------
16 # Prototyped subs must be predeclared because we have a
17 # circular dependency with Moose::Meta::Attribute et. al.
18 # so in case of us being use'd first the predeclaration
19 # ensures the prototypes are in scope when consumers are
22 # creation and location
23 sub find_type_constraint ($);
24 sub find_or_create_type_constraint ($;$);
25 sub create_type_constraint_union (@);
26 sub create_parameterized_type_constraint ($);
41 sub _create_type_constraint ($$$;$$);
42 sub _install_type_coercions ($$);
44 ## --------------------------------------------------------
46 use Moose::Meta::TypeConstraint;
47 use Moose::Meta::TypeConstraint::Union;
48 use Moose::Meta::TypeConstraint::Parameterized;
49 use Moose::Meta::TypeCoercion;
50 use Moose::Meta::TypeCoercion::Union;
51 use Moose::Meta::TypeConstraint::Registry;
54 type subtype as where message optimize_as
60 Sub::Exporter::setup_exporter({
62 groups => { default => [':all'] }
68 # loop through the exports ...
69 foreach my $name (@exports) {
71 if (defined &{$class . '::' . $name}) {
72 my $keyword = \&{$class . '::' . $name};
74 # make sure it is from Moose
75 my $pkg_name = eval { svref_2object($keyword)->GV->STASH->NAME };
77 next if $pkg_name ne 'Moose::Util::TypeConstraints';
79 # and if it is from Moose then undef the slot
80 delete ${$class . '::'}{$name};
85 ## --------------------------------------------------------
86 ## type registry and some useful functions for it
87 ## --------------------------------------------------------
89 my $REGISTRY = Moose::Meta::TypeConstraint::Registry->new;
91 sub get_type_constraint_registry { $REGISTRY }
92 sub list_all_type_constraints { keys %{$REGISTRY->type_constraints} }
93 sub export_type_constraints_as_functions {
96 foreach my $constraint (keys %{$REGISTRY->type_constraints}) {
97 *{"${pkg}::${constraint}"} = $REGISTRY->get_type_constraint($constraint)
98 ->_compiled_type_constraint;
102 sub create_type_constraint_union (@) {
103 my @type_constraint_names;
105 if (scalar @_ == 1 && _detect_type_constraint_union($_[0])) {
106 @type_constraint_names = _parse_type_constraint_union($_[0]);
109 @type_constraint_names = @_;
112 (scalar @type_constraint_names >= 2)
113 || confess "You must pass in at least 2 type names to make a union";
115 ($REGISTRY->has_type_constraint($_))
116 || confess "Could not locate type constraint ($_) for the union"
117 foreach @type_constraint_names;
119 return Moose::Meta::TypeConstraint::Union->new(
120 type_constraints => [
122 $REGISTRY->get_type_constraint($_)
123 } @type_constraint_names
128 sub create_parameterized_type_constraint ($) {
129 my $type_constraint_name = shift;
131 my ($base_type, $type_parameter) = _parse_parameterized_type_constraint($type_constraint_name);
133 (defined $base_type && defined $type_parameter)
134 || confess "Could not parse type name ($type_constraint_name) correctly";
136 ($REGISTRY->has_type_constraint($base_type))
137 || confess "Could not locate the base type ($base_type)";
139 return Moose::Meta::TypeConstraint::Parameterized->new(
140 name => $type_constraint_name,
141 parent => $REGISTRY->get_type_constraint($base_type),
142 type_parameter => find_or_create_type_constraint(
144 parent => $REGISTRY->get_type_constraint('Object'),
145 constraint => sub { $_[0]->isa($type_parameter) }
151 sub find_or_create_type_constraint ($;$) {
152 my ($type_constraint_name, $options_for_anon_type) = @_;
154 return $REGISTRY->get_type_constraint($type_constraint_name)
155 if $REGISTRY->has_type_constraint($type_constraint_name);
159 if (_detect_type_constraint_union($type_constraint_name)) {
160 $constraint = create_type_constraint_union($type_constraint_name);
162 elsif (_detect_parameterized_type_constraint($type_constraint_name)) {
163 $constraint = create_parameterized_type_constraint($type_constraint_name);
167 # otherwise assume that we should create
168 # an ANON type with the $options_for_anon_type
169 # options which can be passed in. It should
170 # be noted that these don't get registered
171 # so we need to return it.
173 return Moose::Meta::TypeConstraint->new(
175 %{$options_for_anon_type}
179 $REGISTRY->add_type_constraint($constraint);
183 ## --------------------------------------------------------
184 ## exported functions ...
185 ## --------------------------------------------------------
187 sub find_type_constraint ($) { $REGISTRY->get_type_constraint(@_) }
192 splice(@_, 1, 0, undef);
193 goto &_create_type_constraint;
196 sub subtype ($$;$$$) {
198 # this adds an undef for the name
199 # if this is an anon-subtype:
200 # subtype(Num => where { $_ % 2 == 0 }) # anon 'even' subtype
201 # but if the last arg is not a code
202 # ref then it is a subtype alias:
203 # subtype(MyNumbers => as Num); # now MyNumbers is the same as Num
204 # ... yeah I know it's ugly code
206 unshift @_ => undef if scalar @_ <= 2 && (reftype($_[1]) || '') eq 'CODE';
207 goto &_create_type_constraint;
211 my ($type_name, @coercion_map) = @_;
212 _install_type_coercions($type_name, \@coercion_map);
216 sub from ($) { $_[0] }
217 sub where (&) { $_[0] }
218 sub via (&) { $_[0] }
220 sub message (&) { +{ message => $_[0] } }
221 sub optimize_as (&) { +{ optimized => $_[0] } }
224 my ($type_name, @values) = @_;
225 (scalar @values >= 2)
226 || confess "You must have at least two values to enumerate through";
227 my %valid = map { $_ => 1 } @values;
228 _create_type_constraint(
235 ## --------------------------------------------------------
236 ## desugaring functions ...
237 ## --------------------------------------------------------
239 sub _create_type_constraint ($$$;$$) {
242 my $check = shift || sub { 1 };
244 my ($message, $optimized);
246 $message = $_->{message} if exists $_->{message};
247 $optimized = $_->{optimized} if exists $_->{optimized};
250 my $pkg_defined_in = scalar(caller(0));
253 my $type = $REGISTRY->get_type_constraint($name);
255 ($type->_package_defined_in eq $pkg_defined_in)
256 || confess ("The type constraint '$name' has already been created in "
257 . $type->_package_defined_in . " and cannot be created again in "
262 $parent = $REGISTRY->get_type_constraint($parent) if defined $parent;
264 my $constraint = Moose::Meta::TypeConstraint->new(
265 name => $name || '__ANON__',
266 package_defined_in => $pkg_defined_in,
268 ($parent ? (parent => $parent ) : ()),
269 ($check ? (constraint => $check) : ()),
270 ($message ? (message => $message) : ()),
271 ($optimized ? (optimized => $optimized) : ()),
274 $REGISTRY->add_type_constraint($constraint)
280 sub _install_type_coercions ($$) {
281 my ($type_name, $coercion_map) = @_;
282 my $type = $REGISTRY->get_type_constraint($type_name);
283 (!$type->has_coercion)
284 || confess "The type coercion for '$type_name' has already been registered";
285 my $type_coercion = Moose::Meta::TypeCoercion->new(
286 type_coercion_map => $coercion_map,
287 type_constraint => $type
289 $type->coercion($type_coercion);
292 ## --------------------------------------------------------
293 ## type notation parsing ...
294 ## --------------------------------------------------------
297 # All I have to say is mugwump++ cause I know
298 # do not even have enough regexp-fu to be able
299 # to have written this (I can only barely
300 # understand it as it is)
305 my $valid_chars = qr{[\w:]};
306 my $type_atom = qr{ $valid_chars+ };
308 my $type = qr{ $valid_chars+ (?: \[ (??{$any}) \] )? }x;
309 my $type_capture_parts = qr{ ($valid_chars+) (?: \[ ((??{$any})) \] )? }x;
310 my $type_with_parameter = qr{ $valid_chars+ \[ (??{$any}) \] }x;
312 my $op_union = qr{ \s* \| \s* }x;
313 my $union = qr{ $type (?: $op_union $type )+ }x;
315 our $any = qr{ $type | $union }x;
317 sub _parse_parameterized_type_constraint {
318 $_[0] =~ m{ $type_capture_parts }x;
322 sub _detect_parameterized_type_constraint {
323 $_[0] =~ m{ ^ $type_with_parameter $ }x;
326 sub _parse_type_constraint_union {
329 while ( $given =~ m{ \G (?: $op_union )? ($type) }gcx ) {
332 (pos($given) eq length($given))
333 || confess "'$given' didn't parse (parse-pos="
341 sub _detect_type_constraint_union {
342 $_[0] =~ m{^ $type $op_union $type ( $op_union .* )? $}x;
346 ## --------------------------------------------------------
347 # define some basic built-in types
348 ## --------------------------------------------------------
350 type 'Any' => where { 1 }; # meta-type including all
351 type 'Item' => where { 1 }; # base-type
353 subtype 'Undef' => as 'Item' => where { !defined($_) };
354 subtype 'Defined' => as 'Item' => where { defined($_) };
358 => where { !defined($_) || $_ eq "" || "$_" eq '1' || "$_" eq '0' };
362 => where { !ref($_) }
363 => optimize_as { defined($_[0]) && !ref($_[0]) };
368 => optimize_as { ref($_[0]) };
373 => optimize_as { defined($_[0]) && !ref($_[0]) };
377 => where { Scalar::Util::looks_like_number($_) }
378 => optimize_as { !ref($_[0]) && Scalar::Util::looks_like_number($_[0]) };
382 => where { "$_" =~ /^-?[0-9]+$/ }
383 => optimize_as { defined($_[0]) && !ref($_[0]) && $_[0] =~ /^-?[0-9]+$/ };
385 subtype 'ScalarRef' => as 'Ref' => where { ref($_) eq 'SCALAR' } => optimize_as { ref($_[0]) eq 'SCALAR' };
386 subtype 'ArrayRef' => as 'Ref' => where { ref($_) eq 'ARRAY' } => optimize_as { ref($_[0]) eq 'ARRAY' };
387 subtype 'HashRef' => as 'Ref' => where { ref($_) eq 'HASH' } => optimize_as { ref($_[0]) eq 'HASH' };
388 subtype 'CodeRef' => as 'Ref' => where { ref($_) eq 'CODE' } => optimize_as { ref($_[0]) eq 'CODE' };
389 subtype 'RegexpRef' => as 'Ref' => where { ref($_) eq 'Regexp' } => optimize_as { ref($_[0]) eq 'Regexp' };
390 subtype 'GlobRef' => as 'Ref' => where { ref($_) eq 'GLOB' } => optimize_as { ref($_[0]) eq 'GLOB' };
393 # scalar filehandles are GLOB refs,
394 # but a GLOB ref is not always a filehandle
397 => where { Scalar::Util::openhandle($_) }
398 => optimize_as { ref($_[0]) eq 'GLOB' && Scalar::Util::openhandle($_[0]) };
401 # blessed(qr/.../) returns true,.. how odd
404 => where { blessed($_) && blessed($_) ne 'Regexp' }
405 => optimize_as { blessed($_[0]) && blessed($_[0]) ne 'Regexp' };
409 => where { $_->can('does') }
410 => optimize_as { blessed($_[0]) && $_[0]->can('does') };
414 => where { eval { $_->isa('UNIVERSAL') } }
415 => optimize_as { !ref($_[0]) && eval { $_[0]->isa('UNIVERSAL') } };
417 ## --------------------------------------------------------
418 # end of built-in types ...
419 ## --------------------------------------------------------
422 my @BUILTINS = list_all_type_constraints();
423 sub list_all_builtin_type_constraints { @BUILTINS }
434 Moose::Util::TypeConstraints - Type constraint system for Moose
438 use Moose::Util::TypeConstraints;
440 type 'Num' => where { Scalar::Util::looks_like_number($_) };
446 subtype 'NaturalLessThanTen'
449 => message { "This number ($_) is not less than ten!" };
455 enum 'RGBColors' => qw(red green blue);
459 This module provides Moose with the ability to create custom type
460 contraints to be used in attribute definition.
462 =head2 Important Caveat
464 This is B<NOT> a type system for Perl 5. These are type constraints,
465 and they are not used by Moose unless you tell it to. No type
466 inference is performed, expression are not typed, etc. etc. etc.
468 This is simply a means of creating small constraint functions which
469 can be used to simplify your own type-checking code.
471 =head2 Slightly Less Important Caveat
473 It is almost always a good idea to quote your type and subtype names.
474 This is to prevent perl from trying to execute the call as an indirect
475 object call. This issue only seems to come up when you have a subtype
476 the same name as a valid class, but when the issue does arise it tends
477 to be quite annoying to debug.
479 So for instance, this:
481 subtype DateTime => as Object => where { $_->isa('DateTime') };
483 will I<Just Work>, while this:
486 subtype DateTime => as Object => where { $_->isa('DateTime') };
488 will fail silently and cause many headaches. The simple way to solve
489 this, as well as future proof your subtypes from classes which have
490 yet to have been created yet, is to simply do this:
493 subtype 'DateTime' => as 'Object' => where { $_->isa('DateTime') };
495 =head2 Default Type Constraints
497 This module also provides a simple hierarchy for Perl 5 types, this
498 could probably use some work, but it works for me at the moment.
521 Suggestions for improvement are welcome.
523 B<NOTE:> The C<Undef> type constraint does not work correctly
524 in every occasion, please use it sparringly.
526 B<NOTE:> The C<ClassName> type constraint is simply a subtype
527 of string which responds true to C<isa('UNIVERSAL')>. This means
528 that your class B<must> be loaded for this type constraint to
529 pass. I know this is not ideal for all, but it is a saner
530 restriction than most others.
532 =head2 Use with Other Constraint Modules
534 This module should play fairly nicely with other constraint
535 modules with only some slight tweaking. The C<where> clause
536 in types is expected to be a C<CODE> reference which checks
537 it's first argument and returns a bool. Since most constraint
538 modules work in a similar way, it should be simple to adapt
539 them to work with Moose.
541 For instance, this is how you could use it with
542 L<Declare::Constraints::Simple> to declare a completely new type.
544 type 'HashOfArrayOfObjects'
547 -values => IsArrayRef( IsObject ));
549 For more examples see the F<t/204_example_w_DCS.t> test file.
551 Here is an example of using L<Test::Deep> and it's non-test
552 related C<eq_deeply> function.
554 type 'ArrayOfHashOfBarsAndRandomNumbers'
557 array_each(subhashof({
559 random_number => ignore()
563 For a complete example see the F<t/205_example_w_TestDeep.t>
568 =head2 Type Constraint Construction & Locating
572 =item B<create_type_constraint_union ($pipe_seperated_types | @type_constraint_names)>
574 Given string with C<$pipe_seperated_types> or a list of C<@type_constraint_names>,
575 this will return a L<Moose::Meta::TypeConstraint::Union> instance.
577 =item B<create_parameterized_type_constraint ($type_name)>
579 Given a C<$type_name> in the form of:
581 BaseType[ContainerType]
583 this will extract the base type and container type and build an instance of
584 L<Moose::Meta::TypeConstraint::Parameterized> for it.
586 =item B<find_or_create_type_constraint ($type_name, ?$options_for_anon_type)>
588 This will attempt to find or create a type constraint given the a C<$type_name>.
589 If it cannot find it in the registry, it will see if it should be a union or
590 container type an create one if appropriate, and lastly if nothing can be
591 found or created that way, it will create an anon-type using the
592 C<$options_for_anon_type> HASH ref to populate it.
594 =item B<find_type_constraint ($type_name)>
596 This function can be used to locate a specific type constraint
597 meta-object, of the class L<Moose::Meta::TypeConstraint> or a
598 derivative. What you do with it from there is up to you :)
600 =item B<get_type_constraint_registry>
602 Fetch the L<Moose::Meta::TypeConstraint::Registry> object which
603 keeps track of all type constraints.
605 =item B<list_all_type_constraints>
607 This will return a list of type constraint names, you can then
608 fetch them using C<find_type_constraint ($type_name)> if you
611 =item B<list_all_builtin_type_constraints>
613 This will return a list of builtin type constraints, meaning,
614 those which are defined in this module. See the section
615 labeled L<Default Type Constraints> for a complete list.
617 =item B<export_type_constraints_as_functions>
619 This will export all the current type constraints as functions
620 into the caller's namespace. Right now, this is mostly used for
621 testing, but it might prove useful to others.
625 =head2 Type Constraint Constructors
627 The following functions are used to create type constraints.
628 They will then register the type constraints in a global store
629 where Moose can get to them if it needs to.
631 See the L<SYNOPSIS> for an example of how to use these.
635 =item B<type ($name, $where_clause)>
637 This creates a base type, which has no parent.
639 =item B<subtype ($name, $parent, $where_clause, ?$message)>
641 This creates a named subtype.
643 =item B<subtype ($parent, $where_clause, ?$message)>
645 This creates an unnamed subtype and will return the type
646 constraint meta-object, which will be an instance of
647 L<Moose::Meta::TypeConstraint>.
649 =item B<enum ($name, @values)>
651 This will create a basic subtype for a given set of strings.
652 The resulting constraint will be a subtype of C<Str> and
653 will match any of the items in C<@values>. It is case sensitive.
654 See the L<SYNOPSIS> for a simple example.
656 B<NOTE:> This is not a true proper enum type, it is simple
657 a convient constraint builder.
661 This is just sugar for the type constraint construction syntax.
665 This is just sugar for the type constraint construction syntax.
669 This is just sugar for the type constraint construction syntax.
673 This can be used to define a "hand optimized" version of your
674 type constraint which can be used to avoid traversing a subtype
675 constraint heirarchy.
677 B<NOTE:> You should only use this if you know what you are doing,
678 all the built in types use this, so your subtypes (assuming they
679 are shallow) will not likely need to use this.
683 =head2 Type Coercion Constructors
685 Type constraints can also contain type coercions as well. If you
686 ask your accessor to coerce, then Moose will run the type-coercion
687 code first, followed by the type constraint check. This feature
688 should be used carefully as it is very powerful and could easily
689 take off a limb if you are not careful.
691 See the L<SYNOPSIS> for an example of how to use these.
699 This is just sugar for the type coercion construction syntax.
703 This is just sugar for the type coercion construction syntax.
707 =head2 Namespace Management
713 This will remove all the type constraint keywords from the
714 calling class namespace.
720 All complex software has bugs lurking in it, and this module is no
721 exception. If you find a bug please either email me, or add the bug
726 Stevan Little E<lt>stevan@iinteractive.comE<gt>
728 =head1 COPYRIGHT AND LICENSE
730 Copyright 2006, 2007 by Infinity Interactive, Inc.
732 L<http://www.iinteractive.com>
734 This library is free software; you can redistribute it and/or modify
735 it under the same terms as Perl itself.