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') };
412 my $_class_name_checker = sub {
413 return if ref($_[0]);
414 return unless defined($_[0]) && length($_[0]);
416 # walk the symbol table tree to avoid autovififying
417 # \*{${main::}{"Foo::"}} == \*main::Foo::
420 foreach my $part (split('::', $_[0])) {
421 return unless exists ${$$pack}{"${part}::"};
422 $pack = \*{${$$pack}{"${part}::"}};
425 # check for $VERSION or @ISA
426 return 1 if exists ${$$pack}{VERSION}
427 && defined *{${$$pack}{VERSION}}{SCALAR};
428 return 1 if exists ${$$pack}{ISA}
429 && defined *{${$$pack}{ISA}}{ARRAY};
431 # check for any method
432 foreach ( keys %{$$pack} ) {
433 next if substr($_, -2, 2) eq '::';
434 return 1 if defined *{${$$pack}{$_}}{CODE};
443 => $_class_name_checker # where ...
444 => { optimize => $_class_name_checker };
446 ## --------------------------------------------------------
447 # end of built-in types ...
448 ## --------------------------------------------------------
451 my @BUILTINS = list_all_type_constraints();
452 sub list_all_builtin_type_constraints { @BUILTINS }
463 Moose::Util::TypeConstraints - Type constraint system for Moose
467 use Moose::Util::TypeConstraints;
469 type 'Num' => where { Scalar::Util::looks_like_number($_) };
475 subtype 'NaturalLessThanTen'
478 => message { "This number ($_) is not less than ten!" };
484 enum 'RGBColors' => qw(red green blue);
488 This module provides Moose with the ability to create custom type
489 contraints to be used in attribute definition.
491 =head2 Important Caveat
493 This is B<NOT> a type system for Perl 5. These are type constraints,
494 and they are not used by Moose unless you tell it to. No type
495 inference is performed, expression are not typed, etc. etc. etc.
497 This is simply a means of creating small constraint functions which
498 can be used to simplify your own type-checking code.
500 =head2 Slightly Less Important Caveat
502 It is almost always a good idea to quote your type and subtype names.
503 This is to prevent perl from trying to execute the call as an indirect
504 object call. This issue only seems to come up when you have a subtype
505 the same name as a valid class, but when the issue does arise it tends
506 to be quite annoying to debug.
508 So for instance, this:
510 subtype DateTime => as Object => where { $_->isa('DateTime') };
512 will I<Just Work>, while this:
515 subtype DateTime => as Object => where { $_->isa('DateTime') };
517 will fail silently and cause many headaches. The simple way to solve
518 this, as well as future proof your subtypes from classes which have
519 yet to have been created yet, is to simply do this:
522 subtype 'DateTime' => as 'Object' => where { $_->isa('DateTime') };
524 =head2 Default Type Constraints
526 This module also provides a simple hierarchy for Perl 5 types, this
527 could probably use some work, but it works for me at the moment.
550 Suggestions for improvement are welcome.
552 B<NOTE:> The C<Undef> type constraint does not work correctly
553 in every occasion, please use it sparringly.
555 B<NOTE:> The C<ClassName> type constraint is simply a subtype
556 of string which responds true to C<isa('UNIVERSAL')>. This means
557 that your class B<must> be loaded for this type constraint to
558 pass. I know this is not ideal for all, but it is a saner
559 restriction than most others.
561 =head2 Use with Other Constraint Modules
563 This module should play fairly nicely with other constraint
564 modules with only some slight tweaking. The C<where> clause
565 in types is expected to be a C<CODE> reference which checks
566 it's first argument and returns a bool. Since most constraint
567 modules work in a similar way, it should be simple to adapt
568 them to work with Moose.
570 For instance, this is how you could use it with
571 L<Declare::Constraints::Simple> to declare a completely new type.
573 type 'HashOfArrayOfObjects'
576 -values => IsArrayRef( IsObject ));
578 For more examples see the F<t/204_example_w_DCS.t> test file.
580 Here is an example of using L<Test::Deep> and it's non-test
581 related C<eq_deeply> function.
583 type 'ArrayOfHashOfBarsAndRandomNumbers'
586 array_each(subhashof({
588 random_number => ignore()
592 For a complete example see the F<t/205_example_w_TestDeep.t>
597 =head2 Type Constraint Construction & Locating
601 =item B<create_type_constraint_union ($pipe_seperated_types | @type_constraint_names)>
603 Given string with C<$pipe_seperated_types> or a list of C<@type_constraint_names>,
604 this will return a L<Moose::Meta::TypeConstraint::Union> instance.
606 =item B<create_parameterized_type_constraint ($type_name)>
608 Given a C<$type_name> in the form of:
610 BaseType[ContainerType]
612 this will extract the base type and container type and build an instance of
613 L<Moose::Meta::TypeConstraint::Parameterized> for it.
615 =item B<find_or_create_type_constraint ($type_name, ?$options_for_anon_type)>
617 This will attempt to find or create a type constraint given the a C<$type_name>.
618 If it cannot find it in the registry, it will see if it should be a union or
619 container type an create one if appropriate, and lastly if nothing can be
620 found or created that way, it will create an anon-type using the
621 C<$options_for_anon_type> HASH ref to populate it.
623 =item B<find_type_constraint ($type_name)>
625 This function can be used to locate a specific type constraint
626 meta-object, of the class L<Moose::Meta::TypeConstraint> or a
627 derivative. What you do with it from there is up to you :)
629 =item B<get_type_constraint_registry>
631 Fetch the L<Moose::Meta::TypeConstraint::Registry> object which
632 keeps track of all type constraints.
634 =item B<list_all_type_constraints>
636 This will return a list of type constraint names, you can then
637 fetch them using C<find_type_constraint ($type_name)> if you
640 =item B<list_all_builtin_type_constraints>
642 This will return a list of builtin type constraints, meaning,
643 those which are defined in this module. See the section
644 labeled L<Default Type Constraints> for a complete list.
646 =item B<export_type_constraints_as_functions>
648 This will export all the current type constraints as functions
649 into the caller's namespace. Right now, this is mostly used for
650 testing, but it might prove useful to others.
654 =head2 Type Constraint Constructors
656 The following functions are used to create type constraints.
657 They will then register the type constraints in a global store
658 where Moose can get to them if it needs to.
660 See the L<SYNOPSIS> for an example of how to use these.
664 =item B<type ($name, $where_clause)>
666 This creates a base type, which has no parent.
668 =item B<subtype ($name, $parent, $where_clause, ?$message)>
670 This creates a named subtype.
672 =item B<subtype ($parent, $where_clause, ?$message)>
674 This creates an unnamed subtype and will return the type
675 constraint meta-object, which will be an instance of
676 L<Moose::Meta::TypeConstraint>.
678 =item B<enum ($name, @values)>
680 This will create a basic subtype for a given set of strings.
681 The resulting constraint will be a subtype of C<Str> and
682 will match any of the items in C<@values>. It is case sensitive.
683 See the L<SYNOPSIS> for a simple example.
685 B<NOTE:> This is not a true proper enum type, it is simple
686 a convient constraint builder.
690 This is just sugar for the type constraint construction syntax.
694 This is just sugar for the type constraint construction syntax.
698 This is just sugar for the type constraint construction syntax.
702 This can be used to define a "hand optimized" version of your
703 type constraint which can be used to avoid traversing a subtype
704 constraint heirarchy.
706 B<NOTE:> You should only use this if you know what you are doing,
707 all the built in types use this, so your subtypes (assuming they
708 are shallow) will not likely need to use this.
712 =head2 Type Coercion Constructors
714 Type constraints can also contain type coercions as well. If you
715 ask your accessor to coerce, then Moose will run the type-coercion
716 code first, followed by the type constraint check. This feature
717 should be used carefully as it is very powerful and could easily
718 take off a limb if you are not careful.
720 See the L<SYNOPSIS> for an example of how to use these.
728 This is just sugar for the type coercion construction syntax.
732 This is just sugar for the type coercion construction syntax.
736 =head2 Namespace Management
742 This will remove all the type constraint keywords from the
743 calling class namespace.
749 All complex software has bugs lurking in it, and this module is no
750 exception. If you find a bug please either email me, or add the bug
755 Stevan Little E<lt>stevan@iinteractive.comE<gt>
757 =head1 COPYRIGHT AND LICENSE
759 Copyright 2006, 2007 by Infinity Interactive, Inc.
761 L<http://www.iinteractive.com>
763 This library is free software; you can redistribute it and/or modify
764 it under the same terms as Perl itself.