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);
305 || confess "Cannot find type '$type_name', perhaps you forgot to load it.";
306 if ($type->has_coercion) {
307 $type->coercion->add_type_coercions(@$coercion_map);
310 my $type_coercion = Moose::Meta::TypeCoercion->new(
311 type_coercion_map => $coercion_map,
312 type_constraint => $type
314 $type->coercion($type_coercion);
318 ## --------------------------------------------------------
319 ## type notation parsing ...
320 ## --------------------------------------------------------
323 # All I have to say is mugwump++ cause I know
324 # do not even have enough regexp-fu to be able
325 # to have written this (I can only barely
326 # understand it as it is)
331 my $valid_chars = qr{[\w:]};
332 my $type_atom = qr{ $valid_chars+ };
334 my $type = qr{ $valid_chars+ (?: \[ (??{$any}) \] )? }x;
335 my $type_capture_parts = qr{ ($valid_chars+) (?: \[ ((??{$any})) \] )? }x;
336 my $type_with_parameter = qr{ $valid_chars+ \[ (??{$any}) \] }x;
338 my $op_union = qr{ \s* \| \s* }x;
339 my $union = qr{ $type (?: $op_union $type )+ }x;
341 our $any = qr{ $type | $union }x;
343 sub _parse_parameterized_type_constraint {
344 $_[0] =~ m{ $type_capture_parts }x;
348 sub _detect_parameterized_type_constraint {
349 $_[0] =~ m{ ^ $type_with_parameter $ }x;
352 sub _parse_type_constraint_union {
355 while ( $given =~ m{ \G (?: $op_union )? ($type) }gcx ) {
358 (pos($given) eq length($given))
359 || confess "'$given' didn't parse (parse-pos="
367 sub _detect_type_constraint_union {
368 $_[0] =~ m{^ $type $op_union $type ( $op_union .* )? $}x;
372 ## --------------------------------------------------------
373 # define some basic built-in types
374 ## --------------------------------------------------------
376 type 'Any' => where { 1 }; # meta-type including all
377 type 'Item' => where { 1 }; # base-type
379 subtype 'Undef' => as 'Item' => where { !defined($_) };
380 subtype 'Defined' => as 'Item' => where { defined($_) };
384 => where { !defined($_) || $_ eq "" || "$_" eq '1' || "$_" eq '0' };
388 => where { !ref($_) }
389 => optimize_as { defined($_[0]) && !ref($_[0]) };
394 => optimize_as { ref($_[0]) };
399 => optimize_as { defined($_[0]) && !ref($_[0]) };
403 => where { Scalar::Util::looks_like_number($_) }
404 => optimize_as { !ref($_[0]) && Scalar::Util::looks_like_number($_[0]) };
408 => where { "$_" =~ /^-?[0-9]+$/ }
409 => optimize_as { defined($_[0]) && !ref($_[0]) && $_[0] =~ /^-?[0-9]+$/ };
411 subtype 'ScalarRef' => as 'Ref' => where { ref($_) eq 'SCALAR' } => optimize_as { ref($_[0]) eq 'SCALAR' };
412 subtype 'ArrayRef' => as 'Ref' => where { ref($_) eq 'ARRAY' } => optimize_as { ref($_[0]) eq 'ARRAY' };
413 subtype 'HashRef' => as 'Ref' => where { ref($_) eq 'HASH' } => optimize_as { ref($_[0]) eq 'HASH' };
414 subtype 'CodeRef' => as 'Ref' => where { ref($_) eq 'CODE' } => optimize_as { ref($_[0]) eq 'CODE' };
415 subtype 'RegexpRef' => as 'Ref' => where { ref($_) eq 'Regexp' } => optimize_as { ref($_[0]) eq 'Regexp' };
416 subtype 'GlobRef' => as 'Ref' => where { ref($_) eq 'GLOB' } => optimize_as { ref($_[0]) eq 'GLOB' };
419 # scalar filehandles are GLOB refs,
420 # but a GLOB ref is not always a filehandle
423 => where { Scalar::Util::openhandle($_) }
424 => optimize_as { ref($_[0]) eq 'GLOB' && Scalar::Util::openhandle($_[0]) };
427 # blessed(qr/.../) returns true,.. how odd
430 => where { blessed($_) && blessed($_) ne 'Regexp' }
431 => optimize_as { blessed($_[0]) && blessed($_[0]) ne 'Regexp' };
435 => where { $_->can('does') }
436 => optimize_as { blessed($_[0]) && $_[0]->can('does') };
438 my $_class_name_checker = sub {
439 return if ref($_[0]);
440 return unless defined($_[0]) && length($_[0]);
442 # walk the symbol table tree to avoid autovififying
443 # \*{${main::}{"Foo::"}} == \*main::Foo::
446 foreach my $part (split('::', $_[0])) {
447 return unless exists ${$$pack}{"${part}::"};
448 $pack = \*{${$$pack}{"${part}::"}};
451 # check for $VERSION or @ISA
452 return 1 if exists ${$$pack}{VERSION}
453 && defined *{${$$pack}{VERSION}}{SCALAR};
454 return 1 if exists ${$$pack}{ISA}
455 && defined *{${$$pack}{ISA}}{ARRAY};
457 # check for any method
458 foreach ( keys %{$$pack} ) {
459 next if substr($_, -2, 2) eq '::';
460 return 1 if defined *{${$$pack}{$_}}{CODE};
469 => $_class_name_checker # where ...
470 => { optimize => $_class_name_checker };
472 ## --------------------------------------------------------
473 # end of built-in types ...
474 ## --------------------------------------------------------
477 my @BUILTINS = list_all_type_constraints();
478 sub list_all_builtin_type_constraints { @BUILTINS }
489 Moose::Util::TypeConstraints - Type constraint system for Moose
493 use Moose::Util::TypeConstraints;
495 type 'Num' => where { Scalar::Util::looks_like_number($_) };
501 subtype 'NaturalLessThanTen'
504 => message { "This number ($_) is not less than ten!" };
510 enum 'RGBColors' => qw(red green blue);
514 This module provides Moose with the ability to create custom type
515 contraints to be used in attribute definition.
517 =head2 Important Caveat
519 This is B<NOT> a type system for Perl 5. These are type constraints,
520 and they are not used by Moose unless you tell it to. No type
521 inference is performed, expression are not typed, etc. etc. etc.
523 This is simply a means of creating small constraint functions which
524 can be used to simplify your own type-checking code.
526 =head2 Slightly Less Important Caveat
528 It is almost always a good idea to quote your type and subtype names.
529 This is to prevent perl from trying to execute the call as an indirect
530 object call. This issue only seems to come up when you have a subtype
531 the same name as a valid class, but when the issue does arise it tends
532 to be quite annoying to debug.
534 So for instance, this:
536 subtype DateTime => as Object => where { $_->isa('DateTime') };
538 will I<Just Work>, while this:
541 subtype DateTime => as Object => where { $_->isa('DateTime') };
543 will fail silently and cause many headaches. The simple way to solve
544 this, as well as future proof your subtypes from classes which have
545 yet to have been created yet, is to simply do this:
548 subtype 'DateTime' => as 'Object' => where { $_->isa('DateTime') };
550 =head2 Default Type Constraints
552 This module also provides a simple hierarchy for Perl 5 types, this
553 could probably use some work, but it works for me at the moment.
576 Suggestions for improvement are welcome.
578 B<NOTE:> The C<Undef> type constraint does not work correctly
579 in every occasion, please use it sparringly.
581 B<NOTE:> The C<ClassName> type constraint is simply a subtype
582 of string which responds true to C<isa('UNIVERSAL')>. This means
583 that your class B<must> be loaded for this type constraint to
584 pass. I know this is not ideal for all, but it is a saner
585 restriction than most others.
587 =head2 Use with Other Constraint Modules
589 This module should play fairly nicely with other constraint
590 modules with only some slight tweaking. The C<where> clause
591 in types is expected to be a C<CODE> reference which checks
592 it's first argument and returns a bool. Since most constraint
593 modules work in a similar way, it should be simple to adapt
594 them to work with Moose.
596 For instance, this is how you could use it with
597 L<Declare::Constraints::Simple> to declare a completely new type.
599 type 'HashOfArrayOfObjects'
602 -values => IsArrayRef( IsObject ));
604 For more examples see the F<t/204_example_w_DCS.t> test file.
606 Here is an example of using L<Test::Deep> and it's non-test
607 related C<eq_deeply> function.
609 type 'ArrayOfHashOfBarsAndRandomNumbers'
612 array_each(subhashof({
614 random_number => ignore()
618 For a complete example see the F<t/205_example_w_TestDeep.t>
623 =head2 Type Constraint Construction & Locating
627 =item B<create_type_constraint_union ($pipe_seperated_types | @type_constraint_names)>
629 Given string with C<$pipe_seperated_types> or a list of C<@type_constraint_names>,
630 this will return a L<Moose::Meta::TypeConstraint::Union> instance.
632 =item B<create_parameterized_type_constraint ($type_name)>
634 Given a C<$type_name> in the form of:
636 BaseType[ContainerType]
638 this will extract the base type and container type and build an instance of
639 L<Moose::Meta::TypeConstraint::Parameterized> for it.
641 =item B<find_or_create_type_constraint ($type_name, ?$options_for_anon_type)>
643 This will attempt to find or create a type constraint given the a C<$type_name>.
644 If it cannot find it in the registry, it will see if it should be a union or
645 container type an create one if appropriate, and lastly if nothing can be
646 found or created that way, it will create an anon-type using the
647 C<$options_for_anon_type> HASH ref to populate it. If the C<$options_for_anon_type>
648 is not specified (it is C<undef>), then it will not create anything and simply
651 =item B<find_type_constraint ($type_name)>
653 This function can be used to locate a specific type constraint
654 meta-object, of the class L<Moose::Meta::TypeConstraint> or a
655 derivative. What you do with it from there is up to you :)
657 =item B<get_type_constraint_registry>
659 Fetch the L<Moose::Meta::TypeConstraint::Registry> object which
660 keeps track of all type constraints.
662 =item B<list_all_type_constraints>
664 This will return a list of type constraint names, you can then
665 fetch them using C<find_type_constraint ($type_name)> if you
668 =item B<list_all_builtin_type_constraints>
670 This will return a list of builtin type constraints, meaning,
671 those which are defined in this module. See the section
672 labeled L<Default Type Constraints> for a complete list.
674 =item B<export_type_constraints_as_functions>
676 This will export all the current type constraints as functions
677 into the caller's namespace. Right now, this is mostly used for
678 testing, but it might prove useful to others.
682 =head2 Type Constraint Constructors
684 The following functions are used to create type constraints.
685 They will then register the type constraints in a global store
686 where Moose can get to them if it needs to.
688 See the L<SYNOPSIS> for an example of how to use these.
692 =item B<type ($name, $where_clause)>
694 This creates a base type, which has no parent.
696 =item B<subtype ($name, $parent, $where_clause, ?$message)>
698 This creates a named subtype.
700 =item B<subtype ($parent, $where_clause, ?$message)>
702 This creates an unnamed subtype and will return the type
703 constraint meta-object, which will be an instance of
704 L<Moose::Meta::TypeConstraint>.
706 =item B<enum ($name, @values)>
708 This will create a basic subtype for a given set of strings.
709 The resulting constraint will be a subtype of C<Str> and
710 will match any of the items in C<@values>. It is case sensitive.
711 See the L<SYNOPSIS> for a simple example.
713 B<NOTE:> This is not a true proper enum type, it is simple
714 a convient constraint builder.
718 This is just sugar for the type constraint construction syntax.
722 This is just sugar for the type constraint construction syntax.
726 This is just sugar for the type constraint construction syntax.
730 This can be used to define a "hand optimized" version of your
731 type constraint which can be used to avoid traversing a subtype
732 constraint heirarchy.
734 B<NOTE:> You should only use this if you know what you are doing,
735 all the built in types use this, so your subtypes (assuming they
736 are shallow) will not likely need to use this.
740 =head2 Type Coercion Constructors
742 Type constraints can also contain type coercions as well. If you
743 ask your accessor to coerce, then Moose will run the type-coercion
744 code first, followed by the type constraint check. This feature
745 should be used carefully as it is very powerful and could easily
746 take off a limb if you are not careful.
748 See the L<SYNOPSIS> for an example of how to use these.
756 This is just sugar for the type coercion construction syntax.
760 This is just sugar for the type coercion construction syntax.
764 =head2 Namespace Management
770 This will remove all the type constraint keywords from the
771 calling class namespace.
777 All complex software has bugs lurking in it, and this module is no
778 exception. If you find a bug please either email me, or add the bug
783 Stevan Little E<lt>stevan@iinteractive.comE<gt>
785 =head1 COPYRIGHT AND LICENSE
787 Copyright 2006, 2007 by Infinity Interactive, Inc.
789 L<http://www.iinteractive.com>
791 This library is free software; you can redistribute it and/or modify
792 it under the same terms as Perl itself.