2 package Moose::Util::TypeConstraints;
8 use Scalar::Util 'blessed', 'reftype';
12 our $VERSION = '0.14';
13 our $AUTHORITY = 'cpan:STEVAN';
15 # Prototyped subs must be predeclared because we have a circular dependency
16 # with Moose::Meta::Attribute et. al. so in case of us being use'd first the
17 # predeclaration ensures the prototypes are in scope when consumers are
20 sub find_type_constraint ($);
21 sub _create_type_constraint ($$$;$$);
22 sub _install_type_coercions ($$);
23 sub create_type_constraint_union (@);
35 use Moose::Meta::TypeConstraint;
36 use Moose::Meta::TypeCoercion;
37 use Moose::Meta::TypeConstraint::Registry;
40 type subtype as where message optimize_as
46 Sub::Exporter::setup_exporter({
48 groups => { default => [':all'] }
54 # loop through the exports ...
55 foreach my $name (@exports) {
57 if (defined &{$class . '::' . $name}) {
58 my $keyword = \&{$class . '::' . $name};
60 # make sure it is from Moose
61 my $pkg_name = eval { svref_2object($keyword)->GV->STASH->NAME };
63 next if $pkg_name ne 'Moose::Util::TypeConstraints';
65 # and if it is from Moose then undef the slot
66 delete ${$class . '::'}{$name};
71 my $REGISTRY = Moose::Meta::TypeConstraint::Registry->new;
73 sub _get_type_constraint_registry { $REGISTRY }
74 sub _dump_type_constraints { $REGISTRY->dump }
76 sub _create_type_constraint ($$$;$$) {
79 my $check = shift || sub { 1 };
81 my ($message, $optimized);
83 $message = $_->{message} if exists $_->{message};
84 $optimized = $_->{optimized} if exists $_->{optimized};
87 my $pkg_defined_in = scalar(caller(0));
90 my $type = $REGISTRY->get_type_constraint($name);
92 ($type->_package_defined_in eq $pkg_defined_in)
93 || confess ("The type constraint '$name' has already been created in "
94 . $type->_package_defined_in . " and cannot be created again in "
99 $parent = $REGISTRY->get_type_constraint($parent) if defined $parent;
100 my $constraint = Moose::Meta::TypeConstraint->new(
101 name => $name || '__ANON__',
103 constraint => $check,
105 optimized => $optimized,
106 package_defined_in => $pkg_defined_in,
109 $REGISTRY->add_type_constraint($constraint)
115 sub _install_type_coercions ($$) {
116 my ($type_name, $coercion_map) = @_;
117 my $type = $REGISTRY->get_type_constraint($type_name);
118 (!$type->has_coercion)
119 || confess "The type coercion for '$type_name' has already been registered";
120 my $type_coercion = Moose::Meta::TypeCoercion->new(
121 type_coercion_map => $coercion_map,
122 type_constraint => $type
124 $type->coercion($type_coercion);
127 sub create_type_constraint_union (@) {
128 my (@type_constraint_names) = @_;
129 return Moose::Meta::TypeConstraint->union(
131 $REGISTRY->get_type_constraint($_)
132 } @type_constraint_names
136 sub export_type_constraints_as_functions {
139 foreach my $constraint (keys %{$REGISTRY->type_constraints}) {
140 *{"${pkg}::${constraint}"} = $REGISTRY->get_type_constraint($constraint)
141 ->_compiled_type_constraint;
145 *Moose::Util::TypeConstraints::export_type_contstraints_as_functions = \&export_type_constraints_as_functions;
147 sub list_all_type_constraints { keys %{$REGISTRY->type_constraints} }
149 ## --------------------------------------------------------
150 ## exported functions ...
151 ## --------------------------------------------------------
153 sub find_type_constraint ($) { $REGISTRY->get_type_constraint(@_) }
158 splice(@_, 1, 0, undef);
159 goto &_create_type_constraint;
162 sub subtype ($$;$$$) {
164 # this adds an undef for the name
165 # if this is an anon-subtype:
166 # subtype(Num => where { $_ % 2 == 0 }) # anon 'even' subtype
167 # but if the last arg is not a code
168 # ref then it is a subtype alias:
169 # subtype(MyNumbers => as Num); # now MyNumbers is the same as Num
170 # ... yeah I know it's ugly code
172 unshift @_ => undef if scalar @_ <= 2 && (reftype($_[1]) || '') eq 'CODE';
173 goto &_create_type_constraint;
177 my ($type_name, @coercion_map) = @_;
178 _install_type_coercions($type_name, \@coercion_map);
182 sub from ($) { $_[0] }
183 sub where (&) { $_[0] }
184 sub via (&) { $_[0] }
186 sub message (&) { +{ message => $_[0] } }
187 sub optimize_as (&) { +{ optimized => $_[0] } }
190 my ($type_name, @values) = @_;
191 (scalar @values >= 2)
192 || confess "You must have at least two values to enumerate through";
193 my $regexp = join '|' => @values;
194 _create_type_constraint(
197 sub { qr/^$regexp$/i }
201 # define some basic types
203 type 'Any' => where { 1 }; # meta-type including all
204 type 'Item' => where { 1 }; # base-type
206 subtype 'Undef' => as 'Item' => where { !defined($_) };
207 subtype 'Defined' => as 'Item' => where { defined($_) };
211 => where { !defined($_) || $_ eq "" || "$_" eq '1' || "$_" eq '0' };
215 => where { !ref($_) }
216 => optimize_as { defined($_[0]) && !ref($_[0]) };
221 => optimize_as { ref($_[0]) };
226 => optimize_as { defined($_[0]) && !ref($_[0]) };
230 => where { Scalar::Util::looks_like_number($_) }
231 => optimize_as { !ref($_[0]) && Scalar::Util::looks_like_number($_[0]) };
235 => where { "$_" =~ /^-?[0-9]+$/ }
236 => optimize_as { defined($_[0]) && !ref($_[0]) && $_[0] =~ /^-?[0-9]+$/ };
238 subtype 'ScalarRef' => as 'Ref' => where { ref($_) eq 'SCALAR' } => optimize_as { ref($_[0]) eq 'SCALAR' };
239 subtype 'ArrayRef' => as 'Ref' => where { ref($_) eq 'ARRAY' } => optimize_as { ref($_[0]) eq 'ARRAY' };
240 subtype 'HashRef' => as 'Ref' => where { ref($_) eq 'HASH' } => optimize_as { ref($_[0]) eq 'HASH' };
241 subtype 'CodeRef' => as 'Ref' => where { ref($_) eq 'CODE' } => optimize_as { ref($_[0]) eq 'CODE' };
242 subtype 'RegexpRef' => as 'Ref' => where { ref($_) eq 'Regexp' } => optimize_as { ref($_[0]) eq 'Regexp' };
243 subtype 'GlobRef' => as 'Ref' => where { ref($_) eq 'GLOB' } => optimize_as { ref($_[0]) eq 'GLOB' };
246 # scalar filehandles are GLOB refs,
247 # but a GLOB ref is not always a filehandle
250 => where { Scalar::Util::openhandle($_) }
251 => optimize_as { ref($_[0]) eq 'GLOB' && Scalar::Util::openhandle($_[0]) };
254 # blessed(qr/.../) returns true,.. how odd
257 => where { blessed($_) && blessed($_) ne 'Regexp' }
258 => optimize_as { blessed($_[0]) && blessed($_[0]) ne 'Regexp' };
262 => where { $_->can('does') }
263 => optimize_as { blessed($_[0]) && $_[0]->can('does') };
267 => where { eval { $_->isa('UNIVERSAL') } }
268 => optimize_as { !ref($_[0]) && eval { $_[0]->isa('UNIVERSAL') } };
271 my @BUILTINS = list_all_type_constraints();
272 sub list_all_builtin_type_constraints { @BUILTINS }
283 Moose::Util::TypeConstraints - Type constraint system for Moose
287 use Moose::Util::TypeConstraints;
289 type 'Num' => where { Scalar::Util::looks_like_number($_) };
295 subtype 'NaturalLessThanTen'
298 => message { "This number ($_) is not less than ten!" };
304 enum 'RGBColors' => qw(red green blue);
308 This module provides Moose with the ability to create custom type
309 contraints to be used in attribute definition.
311 =head2 Important Caveat
313 This is B<NOT> a type system for Perl 5. These are type constraints,
314 and they are not used by Moose unless you tell it to. No type
315 inference is performed, expression are not typed, etc. etc. etc.
317 This is simply a means of creating small constraint functions which
318 can be used to simplify your own type-checking code.
320 =head2 Slightly Less Important Caveat
322 It is almost always a good idea to quote your type and subtype names.
323 This is to prevent perl from trying to execute the call as an indirect
324 object call. This issue only seems to come up when you have a subtype
325 the same name as a valid class, but when the issue does arise it tends
326 to be quite annoying to debug.
328 So for instance, this:
330 subtype DateTime => as Object => where { $_->isa('DateTime') };
332 will I<Just Work>, while this:
335 subtype DateTime => as Object => where { $_->isa('DateTime') };
337 will fail silently and cause many headaches. The simple way to solve
338 this, as well as future proof your subtypes from classes which have
339 yet to have been created yet, is to simply do this:
342 subtype 'DateTime' => as 'Object' => where { $_->isa('DateTime') };
344 =head2 Default Type Constraints
346 This module also provides a simple hierarchy for Perl 5 types, this
347 could probably use some work, but it works for me at the moment.
370 Suggestions for improvement are welcome.
372 B<NOTE:> The C<Undef> type constraint does not work correctly
373 in every occasion, please use it sparringly.
375 B<NOTE:> The C<ClassName> type constraint is simply a subtype
376 of string which responds true to C<isa('UNIVERSAL')>. This means
377 that your class B<must> be loaded for this type constraint to
378 pass. I know this is not ideal for all, but it is a saner
379 restriction than most others.
381 =head2 Use with Other Constraint Modules
383 This module should play fairly nicely with other constraint
384 modules with only some slight tweaking. The C<where> clause
385 in types is expected to be a C<CODE> reference which checks
386 it's first argument and returns a bool. Since most constraint
387 modules work in a similar way, it should be simple to adapt
388 them to work with Moose.
390 For instance, this is how you could use it with
391 L<Declare::Constraints::Simple> to declare a completely new type.
393 type 'HashOfArrayOfObjects'
396 -values => IsArrayRef( IsObject ));
398 For more examples see the F<t/204_example_w_DCS.t> test file.
400 Here is an example of using L<Test::Deep> and it's non-test
401 related C<eq_deeply> function.
403 type 'ArrayOfHashOfBarsAndRandomNumbers'
406 array_each(subhashof({
408 random_number => ignore()
412 For a complete example see the F<t/205_example_w_TestDeep.t>
417 =head2 Type Constraint Registry
421 =item B<find_type_constraint ($type_name)>
423 This function can be used to locate a specific type constraint
424 meta-object, of the class L<Moose::Meta::TypeConstraint> or a
425 derivative. What you do with it from there is up to you :)
427 =item B<create_type_constraint_union (@type_constraint_names)>
429 Given a list of C<@type_constraint_names>, this will return a
430 B<Moose::Meta::TypeConstraint::Union> instance.
432 =item B<export_type_constraints_as_functions>
434 This will export all the current type constraints as functions
435 into the caller's namespace. Right now, this is mostly used for
436 testing, but it might prove useful to others.
438 =item B<export_type_contstraints_as_functions>
440 Alias for the above function.
442 =item B<list_all_type_constraints>
444 This will return a list of type constraint names, you can then
445 fetch them using C<find_type_constraint ($type_name)> if you
448 =item B<list_all_builtin_type_constraints>
450 This will return a list of builtin type constraints, meaning,
451 those which are defined in this module. See the section
452 labeled L<Default Type Constraints> for a complete list.
456 =head2 Type Constraint Constructors
458 The following functions are used to create type constraints.
459 They will then register the type constraints in a global store
460 where Moose can get to them if it needs to.
462 See the L<SYNOPSIS> for an example of how to use these.
466 =item B<type ($name, $where_clause)>
468 This creates a base type, which has no parent.
470 =item B<subtype ($name, $parent, $where_clause, ?$message)>
472 This creates a named subtype.
474 =item B<subtype ($parent, $where_clause, ?$message)>
476 This creates an unnamed subtype and will return the type
477 constraint meta-object, which will be an instance of
478 L<Moose::Meta::TypeConstraint>.
480 =item B<enum ($name, @values)>
482 This will create a basic subtype for a given set of strings.
483 The resulting constraint will be a subtype of C<Str> and
484 will match any of the items in C<@values>. See the L<SYNOPSIS>
485 for a simple example.
487 B<NOTE:> This is not a true proper enum type, it is simple
488 a convient constraint builder.
492 This is just sugar for the type constraint construction syntax.
496 This is just sugar for the type constraint construction syntax.
500 This is just sugar for the type constraint construction syntax.
504 This can be used to define a "hand optimized" version of your
505 type constraint which can be used to avoid traversing a subtype
506 constraint heirarchy.
508 B<NOTE:> You should only use this if you know what you are doing,
509 all the built in types use this, so your subtypes (assuming they
510 are shallow) will not likely need to use this.
514 =head2 Type Coercion Constructors
516 Type constraints can also contain type coercions as well. If you
517 ask your accessor to coerce, then Moose will run the type-coercion
518 code first, followed by the type constraint check. This feature
519 should be used carefully as it is very powerful and could easily
520 take off a limb if you are not careful.
522 See the L<SYNOPSIS> for an example of how to use these.
530 This is just sugar for the type coercion construction syntax.
534 This is just sugar for the type coercion construction syntax.
538 =head2 Namespace Management
544 This will remove all the type constraint keywords from the
545 calling class namespace.
551 All complex software has bugs lurking in it, and this module is no
552 exception. If you find a bug please either email me, or add the bug
557 Stevan Little E<lt>stevan@iinteractive.comE<gt>
559 =head1 COPYRIGHT AND LICENSE
561 Copyright 2006, 2007 by Infinity Interactive, Inc.
563 L<http://www.iinteractive.com>
565 This library is free software; you can redistribute it and/or modify
566 it under the same terms as Perl itself.