2 package Moose::Util::TypeConstraints;
8 use Scalar::Util 'blessed';
10 our $VERSION = '0.05';
12 use Moose::Meta::TypeConstraint;
13 use Moose::Meta::TypeCoercion;
16 require Sub::Exporter;
18 my @exports = qw[type subtype as where message coerce from via find_type_constraint];
20 Sub::Exporter->import(
32 sub find_type_constraint {
33 return $TYPES{$_[0]}->[1]
34 if exists $TYPES{$_[0]};
38 sub _dump_type_constraints {
40 Data::Dumper::Dumper(\%TYPES);
43 sub _create_type_constraint {
44 my ($name, $parent, $check, $message) = @_;
45 my $pkg_defined_in = scalar(caller(1));
46 ($TYPES{$name}->[0] eq $pkg_defined_in)
47 || confess "The type constraint '$name' has already been created "
48 if defined $name && exists $TYPES{$name};
49 $parent = find_type_constraint($parent) if defined $parent;
50 my $constraint = Moose::Meta::TypeConstraint->new(
51 name => $name || '__ANON__',
56 $TYPES{$name} = [ $pkg_defined_in, $constraint ] if defined $name;
60 sub _install_type_coercions {
61 my ($type_name, $coercion_map) = @_;
62 my $type = find_type_constraint($type_name);
63 (!$type->has_coercion)
64 || confess "The type coercion for '$type_name' has already been registered";
65 my $type_coercion = Moose::Meta::TypeCoercion->new(
66 type_coercion_map => $coercion_map,
67 type_constraint => $type
69 $type->coercion($type_coercion);
72 sub export_type_contstraints_as_functions {
75 foreach my $constraint (keys %TYPES) {
76 *{"${pkg}::${constraint}"} = find_type_constraint($constraint)->_compiled_type_constraint;
84 my ($name, $check) = @_;
85 _create_type_constraint($name, undef, $check);
89 unshift @_ => undef if scalar @_ <= 2;
90 _create_type_constraint(@_);
94 my ($type_name, @coercion_map) = @_;
95 _install_type_coercions($type_name, \@coercion_map);
99 sub from ($) { $_[0] }
100 sub where (&) { $_[0] }
101 sub via (&) { $_[0] }
102 sub message (&) { $_[0] }
104 # define some basic types
106 type 'Any' => where { 1 };
108 subtype 'Value' => as 'Any' => where { !ref($_) };
109 subtype 'Ref' => as 'Any' => where { ref($_) };
111 subtype 'Bool' => as 'Any' => where { "$_" eq '1' || "$_" eq '0' };
113 subtype 'Int' => as 'Value' => where { Scalar::Util::looks_like_number($_) };
114 subtype 'Str' => as 'Value' => where { !Scalar::Util::looks_like_number($_) };
116 subtype 'ScalarRef' => as 'Ref' => where { ref($_) eq 'SCALAR' };
118 subtype 'CollectionRef' => as 'Ref' => where { ref($_) eq 'ARRAY' || ref($_) eq 'HASH' };
120 subtype 'ArrayRef' => as 'CollectionRef' => where { ref($_) eq 'ARRAY' };
121 subtype 'HashRef' => as 'CollectionRef' => where { ref($_) eq 'HASH' };
123 subtype 'CodeRef' => as 'Ref' => where { ref($_) eq 'CODE' };
124 subtype 'RegexpRef' => as 'Ref' => where { ref($_) eq 'Regexp' };
127 # blessed(qr/.../) returns true,.. how odd
128 subtype 'Object' => as 'Ref' => where { blessed($_) && blessed($_) ne 'Regexp' };
130 subtype 'Role' => as 'Object' => where { $_->can('does') };
140 Moose::Util::TypeConstraints - Type constraint system for Moose
144 use Moose::Util::TypeConstraints;
146 type Num => where { Scalar::Util::looks_like_number($_) };
152 subtype NaturalLessThanTen
155 => message { "This number ($_) is not less than ten!" };
163 This module provides Moose with the ability to create type contraints
164 to be are used in both attribute definitions and for method argument
167 =head2 Important Caveat
169 This is B<NOT> a type system for Perl 5. These are type constraints,
170 and they are not used by Moose unless you tell it to. No type
171 inference is performed, expression are not typed, etc. etc. etc.
173 This is simply a means of creating small constraint functions which
174 can be used to simplify your own type-checking code.
176 =head2 Default Type Constraints
178 This module also provides a simple hierarchy for Perl 5 types, this
179 could probably use some work, but it works for me at the moment.
196 Suggestions for improvement are welcome.
200 =head2 Type Constraint Registry
204 =item B<find_type_constraint ($type_name)>
206 This function can be used to locate a specific type constraint
207 meta-object. What you do with it from there is up to you :)
209 =item B<export_type_contstraints_as_functions>
211 This will export all the current type constraints as functions
212 into the caller's namespace. Right now, this is mostly used for
213 testing, but it might prove useful to others.
217 =head2 Type Constraint Constructors
219 The following functions are used to create type constraints.
220 They will then register the type constraints in a global store
221 where Moose can get to them if it needs to.
223 See the L<SYNOPOSIS> for an example of how to use these.
227 =item B<type ($name, $where_clause)>
229 This creates a base type, which has no parent.
231 =item B<subtype ($name, $parent, $where_clause, ?$message)>
233 This creates a named subtype.
235 =item B<subtype ($parent, $where_clause, ?$message)>
237 This creates an unnamed subtype and will return the type
238 constraint meta-object, which will be an instance of
239 L<Moose::Meta::TypeConstraint>.
243 This is just sugar for the type constraint construction syntax.
247 This is just sugar for the type constraint construction syntax.
251 This is just sugar for the type constraint construction syntax.
255 =head2 Type Coercion Constructors
257 Type constraints can also contain type coercions as well. In most
258 cases Moose will run the type-coercion code first, followed by the
259 type constraint check. This feature should be used carefully as it
260 is very powerful and could easily take off a limb if you are not
263 See the L<SYNOPOSIS> for an example of how to use these.
271 This is just sugar for the type coercion construction syntax.
275 This is just sugar for the type coercion construction syntax.
281 All complex software has bugs lurking in it, and this module is no
282 exception. If you find a bug please either email me, or add the bug
287 Stevan Little E<lt>stevan@iinteractive.comE<gt>
289 =head1 COPYRIGHT AND LICENSE
291 Copyright 2006 by Infinity Interactive, Inc.
293 L<http://www.iinteractive.com>
295 This library is free software; you can redistribute it and/or modify
296 it under the same terms as Perl itself.