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 (&) { $_[0] }
104 # define some basic types
106 type 'Any' => where { 1 }; # meta-type including all
107 type 'Item' => where { 1 }; # base-type
109 subtype 'Undef' => as 'Item' => where { !defined($_) };
110 subtype 'Defined' => as 'Item' => where { defined($_) };
112 subtype 'Value' => as 'Item' => where { !ref($_) };
113 subtype 'Ref' => as 'Item' => where { ref($_) };
115 subtype 'Bool' => as 'Item' => where { "$_" eq '1' || "$_" eq '0' };
117 subtype 'Int' => as 'Value' => where { Scalar::Util::looks_like_number($_) };
118 subtype 'Str' => as 'Value' => where { !Scalar::Util::looks_like_number($_) };
120 subtype 'ScalarRef' => as 'Ref' => where { ref($_) eq 'SCALAR' };
122 subtype 'CollectionRef' => as 'Ref' => where { ref($_) eq 'ARRAY' || ref($_) eq 'HASH' };
124 subtype 'ArrayRef' => as 'CollectionRef' => where { ref($_) eq 'ARRAY' };
125 subtype 'HashRef' => as 'CollectionRef' => where { ref($_) eq 'HASH' };
127 subtype 'CodeRef' => as 'Ref' => where { ref($_) eq 'CODE' };
128 subtype 'RegexpRef' => as 'Ref' => where { ref($_) eq 'Regexp' };
131 # blessed(qr/.../) returns true,.. how odd
132 subtype 'Object' => as 'Ref' => where { blessed($_) && blessed($_) ne 'Regexp' };
134 subtype 'Role' => as 'Object' => where { $_->can('does') };
144 Moose::Util::TypeConstraints - Type constraint system for Moose
148 use Moose::Util::TypeConstraints;
150 type Num => where { Scalar::Util::looks_like_number($_) };
156 subtype NaturalLessThanTen
159 => message { "This number ($_) is not less than ten!" };
167 This module provides Moose with the ability to create type contraints
168 to be are used in both attribute definitions and for method argument
171 =head2 Important Caveat
173 This is B<NOT> a type system for Perl 5. These are type constraints,
174 and they are not used by Moose unless you tell it to. No type
175 inference is performed, expression are not typed, etc. etc. etc.
177 This is simply a means of creating small constraint functions which
178 can be used to simplify your own type-checking code.
180 =head2 Default Type Constraints
182 This module also provides a simple hierarchy for Perl 5 types, this
183 could probably use some work, but it works for me at the moment.
204 Suggestions for improvement are welcome.
208 =head2 Type Constraint Registry
212 =item B<find_type_constraint ($type_name)>
214 This function can be used to locate a specific type constraint
215 meta-object. What you do with it from there is up to you :)
217 =item B<export_type_contstraints_as_functions>
219 This will export all the current type constraints as functions
220 into the caller's namespace. Right now, this is mostly used for
221 testing, but it might prove useful to others.
225 =head2 Type Constraint Constructors
227 The following functions are used to create type constraints.
228 They will then register the type constraints in a global store
229 where Moose can get to them if it needs to.
231 See the L<SYNOPOSIS> for an example of how to use these.
235 =item B<type ($name, $where_clause)>
237 This creates a base type, which has no parent.
239 =item B<subtype ($name, $parent, $where_clause, ?$message)>
241 This creates a named subtype.
243 =item B<subtype ($parent, $where_clause, ?$message)>
245 This creates an unnamed subtype and will return the type
246 constraint meta-object, which will be an instance of
247 L<Moose::Meta::TypeConstraint>.
251 This is just sugar for the type constraint construction syntax.
255 This is just sugar for the type constraint construction syntax.
259 This is just sugar for the type constraint construction syntax.
263 =head2 Type Coercion Constructors
265 Type constraints can also contain type coercions as well. In most
266 cases Moose will run the type-coercion code first, followed by the
267 type constraint check. This feature should be used carefully as it
268 is very powerful and could easily take off a limb if you are not
271 See the L<SYNOPOSIS> for an example of how to use these.
279 This is just sugar for the type coercion construction syntax.
283 This is just sugar for the type coercion construction syntax.
289 All complex software has bugs lurking in it, and this module is no
290 exception. If you find a bug please either email me, or add the bug
295 Stevan Little E<lt>stevan@iinteractive.comE<gt>
297 =head1 COPYRIGHT AND LICENSE
299 Copyright 2006 by Infinity Interactive, Inc.
301 L<http://www.iinteractive.com>
303 This library is free software; you can redistribute it and/or modify
304 it under the same terms as Perl itself.