2 package Moose::Util::TypeConstraints;
8 use Scalar::Util 'blessed';
10 our $VERSION = '0.04';
12 use Moose::Meta::TypeConstraint;
13 use Moose::Meta::TypeCoercion;
17 my $pkg = shift || caller();
18 return if $pkg eq '-no-export';
20 foreach my $export (qw(type subtype as where message coerce from via find_type_constraint)) {
21 *{"${pkg}::${export}"} = \&{"${export}"};
27 sub find_type_constraint {
28 return $TYPES{$_[0]}->[1]
29 if exists $TYPES{$_[0]};
33 sub _dump_type_constraints {
35 Data::Dumper::Dumper(\%TYPES);
38 sub _create_type_constraint {
39 my ($name, $parent, $check, $message) = @_;
40 my $pkg_defined_in = scalar(caller(1));
41 ($TYPES{$name}->[0] eq $pkg_defined_in)
42 || confess "The type constraint '$name' has already been created "
43 if defined $name && exists $TYPES{$name};
44 $parent = find_type_constraint($parent) if defined $parent;
45 my $constraint = Moose::Meta::TypeConstraint->new(
46 name => $name || '__ANON__',
51 $TYPES{$name} = [ $pkg_defined_in, $constraint ] if defined $name;
55 sub _install_type_coercions {
56 my ($type_name, $coercion_map) = @_;
57 my $type = find_type_constraint($type_name);
58 (!$type->has_coercion)
59 || confess "The type coercion for '$type_name' has already been registered";
60 my $type_coercion = Moose::Meta::TypeCoercion->new(
61 type_coercion_map => $coercion_map,
62 type_constraint => $type
64 $type->coercion($type_coercion);
67 sub export_type_contstraints_as_functions {
70 foreach my $constraint (keys %TYPES) {
71 *{"${pkg}::${constraint}"} = find_type_constraint($constraint)->_compiled_type_constraint;
79 my ($name, $check) = @_;
80 _create_type_constraint($name, undef, $check);
84 unshift @_ => undef if scalar @_ <= 2;
85 _create_type_constraint(@_);
89 my ($type_name, @coercion_map) = @_;
90 _install_type_coercions($type_name, \@coercion_map);
94 sub from ($) { $_[0] }
95 sub where (&) { $_[0] }
97 sub message (&) { $_[0] }
99 # define some basic types
101 type 'Any' => where { 1 };
103 subtype 'Value' => as 'Any' => where { !ref($_) };
104 subtype 'Ref' => as 'Any' => where { ref($_) };
106 subtype 'Int' => as 'Value' => where { Scalar::Util::looks_like_number($_) };
107 subtype 'Str' => as 'Value' => where { !Scalar::Util::looks_like_number($_) };
109 subtype 'ScalarRef' => as 'Ref' => where { ref($_) eq 'SCALAR' };
110 subtype 'ArrayRef' => as 'Ref' => where { ref($_) eq 'ARRAY' };
111 subtype 'HashRef' => as 'Ref' => where { ref($_) eq 'HASH' };
112 subtype 'CodeRef' => as 'Ref' => where { ref($_) eq 'CODE' };
113 subtype 'RegexpRef' => as 'Ref' => where { ref($_) eq 'Regexp' };
116 # blessed(qr/.../) returns true,.. how odd
117 subtype 'Object' => as 'Ref' => where { blessed($_) && blessed($_) ne 'Regexp' };
127 Moose::Util::TypeConstraints - Type constraint system for Moose
131 use Moose::Util::TypeConstraints;
133 type Num => where { Scalar::Util::looks_like_number($_) };
139 subtype NaturalLessThanTen
142 => message { "This number ($_) is not less than ten!" };
150 This module provides Moose with the ability to create type contraints
151 to be are used in both attribute definitions and for method argument
154 =head2 Important Caveat
156 This is B<NOT> a type system for Perl 5. These are type constraints,
157 and they are not used by Moose unless you tell it to. No type
158 inference is performed, expression are not typed, etc. etc. etc.
160 This is simply a means of creating small constraint functions which
161 can be used to simplify your own type-checking code.
163 =head2 Default Type Constraints
165 This module also provides a simple hierarchy for Perl 5 types, this
166 could probably use some work, but it works for me at the moment.
180 Suggestions for improvement are welcome.
184 =head2 Type Constraint Registry
188 =item B<find_type_constraint ($type_name)>
190 This function can be used to locate a specific type constraint
191 meta-object. What you do with it from there is up to you :)
193 =item B<export_type_contstraints_as_functions>
195 This will export all the current type constraints as functions
196 into the caller's namespace. Right now, this is mostly used for
197 testing, but it might prove useful to others.
201 =head2 Type Constraint Constructors
203 The following functions are used to create type constraints.
204 They will then register the type constraints in a global store
205 where Moose can get to them if it needs to.
207 See the L<SYNOPOSIS> for an example of how to use these.
211 =item B<type ($name, $where_clause)>
213 This creates a base type, which has no parent.
215 =item B<subtype ($name, $parent, $where_clause, ?$message)>
217 This creates a named subtype.
219 =item B<subtype ($parent, $where_clause, ?$message)>
221 This creates an unnamed subtype and will return the type
222 constraint meta-object, which will be an instance of
223 L<Moose::Meta::TypeConstraint>.
227 This is just sugar for the type constraint construction syntax.
231 This is just sugar for the type constraint construction syntax.
235 This is just sugar for the type constraint construction syntax.
239 =head2 Type Coercion Constructors
241 Type constraints can also contain type coercions as well. In most
242 cases Moose will run the type-coercion code first, followed by the
243 type constraint check. This feature should be used carefully as it
244 is very powerful and could easily take off a limb if you are not
247 See the L<SYNOPOSIS> for an example of how to use these.
255 This is just sugar for the type coercion construction syntax.
259 This is just sugar for the type coercion construction syntax.
265 All complex software has bugs lurking in it, and this module is no
266 exception. If you find a bug please either email me, or add the bug
271 Stevan Little E<lt>stevan@iinteractive.comE<gt>
273 =head1 COPYRIGHT AND LICENSE
275 Copyright 2006 by Infinity Interactive, Inc.
277 L<http://www.iinteractive.com>
279 This library is free software; you can redistribute it and/or modify
280 it under the same terms as Perl itself.