2 package Moose::Util::TypeConstraints;
8 use Scalar::Util 'blessed', 'reftype';
12 our $VERSION = '0.17';
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 # if there is no $options_for_anon_type
168 # specified, then we assume they don't
169 # want to create one, and return nothing.
170 return unless defined $options_for_anon_type;
173 # otherwise assume that we should create
174 # an ANON type with the $options_for_anon_type
175 # options which can be passed in. It should
176 # be noted that these don't get registered
177 # so we need to return it.
179 return Moose::Meta::TypeConstraint->new(
181 %{$options_for_anon_type}
185 $REGISTRY->add_type_constraint($constraint);
189 ## --------------------------------------------------------
190 ## exported functions ...
191 ## --------------------------------------------------------
193 sub find_type_constraint ($) { $REGISTRY->get_type_constraint(@_) }
198 splice(@_, 1, 0, undef);
199 goto &_create_type_constraint;
202 sub subtype ($$;$$$) {
204 # this adds an undef for the name
205 # if this is an anon-subtype:
206 # subtype(Num => where { $_ % 2 == 0 }) # anon 'even' subtype
207 # but if the last arg is not a code
208 # ref then it is a subtype alias:
209 # subtype(MyNumbers => as Num); # now MyNumbers is the same as Num
210 # ... yeah I know it's ugly code
212 unshift @_ => undef if scalar @_ <= 2 && (reftype($_[1]) || '') eq 'CODE';
213 goto &_create_type_constraint;
217 my ($type_name, @coercion_map) = @_;
218 _install_type_coercions($type_name, \@coercion_map);
222 sub from ($) { $_[0] }
223 sub where (&) { $_[0] }
224 sub via (&) { $_[0] }
226 sub message (&) { +{ message => $_[0] } }
227 sub optimize_as (&) { +{ optimized => $_[0] } }
230 my ($type_name, @values) = @_;
231 (scalar @values >= 2)
232 || confess "You must have at least two values to enumerate through";
233 my %valid = map { $_ => 1 } @values;
234 _create_type_constraint(
241 ## --------------------------------------------------------
242 ## desugaring functions ...
243 ## --------------------------------------------------------
245 sub _create_type_constraint ($$$;$$) {
250 my ($message, $optimized);
252 $message = $_->{message} if exists $_->{message};
253 $optimized = $_->{optimized} if exists $_->{optimized};
256 my $pkg_defined_in = scalar(caller(0));
259 my $type = $REGISTRY->get_type_constraint($name);
261 ($type->_package_defined_in eq $pkg_defined_in)
262 || confess ("The type constraint '$name' has already been created in "
263 . $type->_package_defined_in . " and cannot be created again in "
268 $parent = find_or_create_type_constraint($parent) if defined $parent;
270 my $constraint = Moose::Meta::TypeConstraint->new(
271 name => $name || '__ANON__',
272 package_defined_in => $pkg_defined_in,
274 ($parent ? (parent => $parent ) : ()),
275 ($check ? (constraint => $check) : ()),
276 ($message ? (message => $message) : ()),
277 ($optimized ? (optimized => $optimized) : ()),
281 # if we have a type constraint union, and no
282 # type check, this means we are just aliasing
283 # the union constraint, which means we need to
284 # handle this differently.
286 if (not(defined($check))
287 && $parent->isa('Moose::Meta::TypeConstraint::Union')
288 && $parent->has_coercion
290 $constraint->coercion(Moose::Meta::TypeCoercion::Union->new(
291 type_constraint => $parent
295 $REGISTRY->add_type_constraint($constraint)
301 sub _install_type_coercions ($$) {
302 my ($type_name, $coercion_map) = @_;
303 my $type = $REGISTRY->get_type_constraint($type_name);
304 if ($type->has_coercion) {
305 $type->coercion->add_type_coercions(@$coercion_map);
308 my $type_coercion = Moose::Meta::TypeCoercion->new(
309 type_coercion_map => $coercion_map,
310 type_constraint => $type
312 $type->coercion($type_coercion);
316 ## --------------------------------------------------------
317 ## type notation parsing ...
318 ## --------------------------------------------------------
321 # All I have to say is mugwump++ cause I know
322 # do not even have enough regexp-fu to be able
323 # to have written this (I can only barely
324 # understand it as it is)
329 my $valid_chars = qr{[\w:]};
330 my $type_atom = qr{ $valid_chars+ };
332 my $type = qr{ $valid_chars+ (?: \[ (??{$any}) \] )? }x;
333 my $type_capture_parts = qr{ ($valid_chars+) (?: \[ ((??{$any})) \] )? }x;
334 my $type_with_parameter = qr{ $valid_chars+ \[ (??{$any}) \] }x;
336 my $op_union = qr{ \s* \| \s* }x;
337 my $union = qr{ $type (?: $op_union $type )+ }x;
339 our $any = qr{ $type | $union }x;
341 sub _parse_parameterized_type_constraint {
342 $_[0] =~ m{ $type_capture_parts }x;
346 sub _detect_parameterized_type_constraint {
347 $_[0] =~ m{ ^ $type_with_parameter $ }x;
350 sub _parse_type_constraint_union {
353 while ( $given =~ m{ \G (?: $op_union )? ($type) }gcx ) {
356 (pos($given) eq length($given))
357 || confess "'$given' didn't parse (parse-pos="
365 sub _detect_type_constraint_union {
366 $_[0] =~ m{^ $type $op_union $type ( $op_union .* )? $}x;
370 ## --------------------------------------------------------
371 # define some basic built-in types
372 ## --------------------------------------------------------
374 type 'Any' => where { 1 }; # meta-type including all
375 type 'Item' => where { 1 }; # base-type
377 subtype 'Undef' => as 'Item' => where { !defined($_) };
378 subtype 'Defined' => as 'Item' => where { defined($_) };
382 => where { !defined($_) || $_ eq "" || "$_" eq '1' || "$_" eq '0' };
386 => where { !ref($_) }
387 => optimize_as { defined($_[0]) && !ref($_[0]) };
392 => optimize_as { ref($_[0]) };
397 => optimize_as { defined($_[0]) && !ref($_[0]) };
401 => where { Scalar::Util::looks_like_number($_) }
402 => optimize_as { !ref($_[0]) && Scalar::Util::looks_like_number($_[0]) };
406 => where { "$_" =~ /^-?[0-9]+$/ }
407 => optimize_as { defined($_[0]) && !ref($_[0]) && $_[0] =~ /^-?[0-9]+$/ };
409 subtype 'ScalarRef' => as 'Ref' => where { ref($_) eq 'SCALAR' } => optimize_as { ref($_[0]) eq 'SCALAR' };
410 subtype 'ArrayRef' => as 'Ref' => where { ref($_) eq 'ARRAY' } => optimize_as { ref($_[0]) eq 'ARRAY' };
411 subtype 'HashRef' => as 'Ref' => where { ref($_) eq 'HASH' } => optimize_as { ref($_[0]) eq 'HASH' };
412 subtype 'CodeRef' => as 'Ref' => where { ref($_) eq 'CODE' } => optimize_as { ref($_[0]) eq 'CODE' };
413 subtype 'RegexpRef' => as 'Ref' => where { ref($_) eq 'Regexp' } => optimize_as { ref($_[0]) eq 'Regexp' };
414 subtype 'GlobRef' => as 'Ref' => where { ref($_) eq 'GLOB' } => optimize_as { ref($_[0]) eq 'GLOB' };
417 # scalar filehandles are GLOB refs,
418 # but a GLOB ref is not always a filehandle
421 => where { Scalar::Util::openhandle($_) }
422 => optimize_as { ref($_[0]) eq 'GLOB' && Scalar::Util::openhandle($_[0]) };
425 # blessed(qr/.../) returns true,.. how odd
428 => where { blessed($_) && blessed($_) ne 'Regexp' }
429 => optimize_as { blessed($_[0]) && blessed($_[0]) ne 'Regexp' };
433 => where { $_->can('does') }
434 => optimize_as { blessed($_[0]) && $_[0]->can('does') };
436 my $_class_name_checker = sub {
437 return if ref($_[0]);
438 return unless defined($_[0]) && length($_[0]);
440 # walk the symbol table tree to avoid autovififying
441 # \*{${main::}{"Foo::"}} == \*main::Foo::
444 foreach my $part (split('::', $_[0])) {
445 return unless exists ${$$pack}{"${part}::"};
446 $pack = \*{${$$pack}{"${part}::"}};
449 # check for $VERSION or @ISA
450 return 1 if exists ${$$pack}{VERSION}
451 && defined *{${$$pack}{VERSION}}{SCALAR};
452 return 1 if exists ${$$pack}{ISA}
453 && defined *{${$$pack}{ISA}}{ARRAY};
455 # check for any method
456 foreach ( keys %{$$pack} ) {
457 next if substr($_, -2, 2) eq '::';
458 return 1 if defined *{${$$pack}{$_}}{CODE};
467 => $_class_name_checker # where ...
468 => { optimize => $_class_name_checker };
470 ## --------------------------------------------------------
471 # end of built-in types ...
472 ## --------------------------------------------------------
475 my @BUILTINS = list_all_type_constraints();
476 sub list_all_builtin_type_constraints { @BUILTINS }
487 Moose::Util::TypeConstraints - Type constraint system for Moose
491 use Moose::Util::TypeConstraints;
493 type 'Num' => where { Scalar::Util::looks_like_number($_) };
499 subtype 'NaturalLessThanTen'
502 => message { "This number ($_) is not less than ten!" };
508 enum 'RGBColors' => qw(red green blue);
512 This module provides Moose with the ability to create custom type
513 contraints to be used in attribute definition.
515 =head2 Important Caveat
517 This is B<NOT> a type system for Perl 5. These are type constraints,
518 and they are not used by Moose unless you tell it to. No type
519 inference is performed, expression are not typed, etc. etc. etc.
521 This is simply a means of creating small constraint functions which
522 can be used to simplify your own type-checking code.
524 =head2 Slightly Less Important Caveat
526 It is almost always a good idea to quote your type and subtype names.
527 This is to prevent perl from trying to execute the call as an indirect
528 object call. This issue only seems to come up when you have a subtype
529 the same name as a valid class, but when the issue does arise it tends
530 to be quite annoying to debug.
532 So for instance, this:
534 subtype DateTime => as Object => where { $_->isa('DateTime') };
536 will I<Just Work>, while this:
539 subtype DateTime => as Object => where { $_->isa('DateTime') };
541 will fail silently and cause many headaches. The simple way to solve
542 this, as well as future proof your subtypes from classes which have
543 yet to have been created yet, is to simply do this:
546 subtype 'DateTime' => as 'Object' => where { $_->isa('DateTime') };
548 =head2 Default Type Constraints
550 This module also provides a simple hierarchy for Perl 5 types, this
551 could probably use some work, but it works for me at the moment.
574 Suggestions for improvement are welcome.
576 B<NOTE:> The C<Undef> type constraint does not work correctly
577 in every occasion, please use it sparringly.
579 B<NOTE:> The C<ClassName> type constraint is simply a subtype
580 of string which responds true to C<isa('UNIVERSAL')>. This means
581 that your class B<must> be loaded for this type constraint to
582 pass. I know this is not ideal for all, but it is a saner
583 restriction than most others.
585 =head2 Use with Other Constraint Modules
587 This module should play fairly nicely with other constraint
588 modules with only some slight tweaking. The C<where> clause
589 in types is expected to be a C<CODE> reference which checks
590 it's first argument and returns a bool. Since most constraint
591 modules work in a similar way, it should be simple to adapt
592 them to work with Moose.
594 For instance, this is how you could use it with
595 L<Declare::Constraints::Simple> to declare a completely new type.
597 type 'HashOfArrayOfObjects'
600 -values => IsArrayRef( IsObject ));
602 For more examples see the F<t/204_example_w_DCS.t> test file.
604 Here is an example of using L<Test::Deep> and it's non-test
605 related C<eq_deeply> function.
607 type 'ArrayOfHashOfBarsAndRandomNumbers'
610 array_each(subhashof({
612 random_number => ignore()
616 For a complete example see the F<t/205_example_w_TestDeep.t>
621 =head2 Type Constraint Construction & Locating
625 =item B<create_type_constraint_union ($pipe_seperated_types | @type_constraint_names)>
627 Given string with C<$pipe_seperated_types> or a list of C<@type_constraint_names>,
628 this will return a L<Moose::Meta::TypeConstraint::Union> instance.
630 =item B<create_parameterized_type_constraint ($type_name)>
632 Given a C<$type_name> in the form of:
634 BaseType[ContainerType]
636 this will extract the base type and container type and build an instance of
637 L<Moose::Meta::TypeConstraint::Parameterized> for it.
639 =item B<find_or_create_type_constraint ($type_name, ?$options_for_anon_type)>
641 This will attempt to find or create a type constraint given the a C<$type_name>.
642 If it cannot find it in the registry, it will see if it should be a union or
643 container type an create one if appropriate, and lastly if nothing can be
644 found or created that way, it will create an anon-type using the
645 C<$options_for_anon_type> HASH ref to populate it. If the C<$options_for_anon_type>
646 is not specified (it is C<undef>), then it will not create anything and simply
649 =item B<find_type_constraint ($type_name)>
651 This function can be used to locate a specific type constraint
652 meta-object, of the class L<Moose::Meta::TypeConstraint> or a
653 derivative. What you do with it from there is up to you :)
655 =item B<get_type_constraint_registry>
657 Fetch the L<Moose::Meta::TypeConstraint::Registry> object which
658 keeps track of all type constraints.
660 =item B<list_all_type_constraints>
662 This will return a list of type constraint names, you can then
663 fetch them using C<find_type_constraint ($type_name)> if you
666 =item B<list_all_builtin_type_constraints>
668 This will return a list of builtin type constraints, meaning,
669 those which are defined in this module. See the section
670 labeled L<Default Type Constraints> for a complete list.
672 =item B<export_type_constraints_as_functions>
674 This will export all the current type constraints as functions
675 into the caller's namespace. Right now, this is mostly used for
676 testing, but it might prove useful to others.
680 =head2 Type Constraint Constructors
682 The following functions are used to create type constraints.
683 They will then register the type constraints in a global store
684 where Moose can get to them if it needs to.
686 See the L<SYNOPSIS> for an example of how to use these.
690 =item B<type ($name, $where_clause)>
692 This creates a base type, which has no parent.
694 =item B<subtype ($name, $parent, $where_clause, ?$message)>
696 This creates a named subtype.
698 =item B<subtype ($parent, $where_clause, ?$message)>
700 This creates an unnamed subtype and will return the type
701 constraint meta-object, which will be an instance of
702 L<Moose::Meta::TypeConstraint>.
704 =item B<enum ($name, @values)>
706 This will create a basic subtype for a given set of strings.
707 The resulting constraint will be a subtype of C<Str> and
708 will match any of the items in C<@values>. It is case sensitive.
709 See the L<SYNOPSIS> for a simple example.
711 B<NOTE:> This is not a true proper enum type, it is simple
712 a convient constraint builder.
716 This is just sugar for the type constraint construction syntax.
720 This is just sugar for the type constraint construction syntax.
724 This is just sugar for the type constraint construction syntax.
728 This can be used to define a "hand optimized" version of your
729 type constraint which can be used to avoid traversing a subtype
730 constraint heirarchy.
732 B<NOTE:> You should only use this if you know what you are doing,
733 all the built in types use this, so your subtypes (assuming they
734 are shallow) will not likely need to use this.
738 =head2 Type Coercion Constructors
740 Type constraints can also contain type coercions as well. If you
741 ask your accessor to coerce, then Moose will run the type-coercion
742 code first, followed by the type constraint check. This feature
743 should be used carefully as it is very powerful and could easily
744 take off a limb if you are not careful.
746 See the L<SYNOPSIS> for an example of how to use these.
754 This is just sugar for the type coercion construction syntax.
758 This is just sugar for the type coercion construction syntax.
762 =head2 Namespace Management
768 This will remove all the type constraint keywords from the
769 calling class namespace.
775 All complex software has bugs lurking in it, and this module is no
776 exception. If you find a bug please either email me, or add the bug
781 Stevan Little E<lt>stevan@iinteractive.comE<gt>
783 =head1 COPYRIGHT AND LICENSE
785 Copyright 2006, 2007 by Infinity Interactive, Inc.
787 L<http://www.iinteractive.com>
789 This library is free software; you can redistribute it and/or modify
790 it under the same terms as Perl itself.