2 package Moose::Util::TypeConstraints;
8 use Scalar::Util 'blessed';
10 our $VERSION = '0.03';
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 $export (qw(type subtype as where coerce from via find_type_constraint)) {
21 *{"${pkg}::${export}"} = \&{"${export}"};
27 sub find_type_constraint { $TYPES{$_[0]}->[1] }
29 sub _create_type_constraint {
30 my ($name, $parent, $check) = @_;
31 my $pkg_defined_in = scalar(caller(1));
32 ($TYPES{$name}->[0] eq $pkg_defined_in)
33 || confess "The type constraint '$name' has already been created"
34 if defined $name && exists $TYPES{$name};
35 $parent = find_type_constraint($parent) if defined $parent;
36 my $constraint = Moose::Meta::TypeConstraint->new(
37 name => $name || '__ANON__',
41 $TYPES{$name} = [ $pkg_defined_in, $constraint ] if defined $name;
45 sub _install_type_coercions {
46 my ($type_name, $coercion_map) = @_;
47 my $type = find_type_constraint($type_name);
48 (!$type->has_coercion)
49 || confess "The type coercion for '$type_name' has already been registered";
50 my $type_coercion = Moose::Meta::TypeCoercion->new(
51 type_coercion_map => $coercion_map,
52 type_constraint => $type
54 $type->coercion($type_coercion);
57 sub export_type_contstraints_as_functions {
60 foreach my $constraint (keys %TYPES) {
61 *{"${pkg}::${constraint}"} = find_type_constraint($constraint)->_compiled_type_constraint;
69 my ($name, $check) = @_;
70 _create_type_constraint($name, undef, $check);
74 unshift @_ => undef if scalar @_ == 2;
75 _create_type_constraint(@_);
79 my ($type_name, @coercion_map) = @_;
80 _install_type_coercions($type_name, \@coercion_map);
84 sub from ($) { $_[0] }
85 sub where (&) { $_[0] }
88 # define some basic types
90 type Any => where { 1 };
92 type Value => where { !ref($_) };
93 type Ref => where { ref($_) };
95 subtype Int => as Value => where { Scalar::Util::looks_like_number($_) };
96 subtype Str => as Value => where { !Scalar::Util::looks_like_number($_) };
98 subtype ScalarRef => as Ref => where { ref($_) eq 'SCALAR' };
99 subtype ArrayRef => as Ref => where { ref($_) eq 'ARRAY' };
100 subtype HashRef => as Ref => where { ref($_) eq 'HASH' };
101 subtype CodeRef => as Ref => where { ref($_) eq 'CODE' };
102 subtype RegexpRef => as Ref => where { ref($_) eq 'Regexp' };
105 # blessed(qr/.../) returns true,.. how odd
106 subtype Object => as Ref => where { blessed($_) && blessed($_) ne 'Regexp' };
116 Moose::Util::TypeConstraints - Type constraint system for Moose
120 use Moose::Util::TypeConstraints;
122 type Num => where { Scalar::Util::looks_like_number($_) };
128 subtype NaturalLessThanTen
130 => where { $_ < 10 };
138 This module provides Moose with the ability to create type contraints
139 to be are used in both attribute definitions and for method argument
142 =head2 Important Caveat
144 This is B<NOT> a type system for Perl 5. These are type constraints,
145 and they are not used by Moose unless you tell it to. No type
146 inference is performed, expression are not typed, etc. etc. etc.
148 This is simply a means of creating small constraint functions which
149 can be used to simplify your own type-checking code.
151 =head2 Default Type Constraints
153 This module also provides a simple hierarchy for Perl 5 types, this
154 could probably use some work, but it works for me at the moment.
168 Suggestions for improvement are welcome.
172 =head2 Type Constraint Registry
176 =item B<find_type_constraint ($type_name)>
178 This function can be used to locate a specific type constraint
179 meta-object. What you do with it from there is up to you :)
181 =item B<export_type_contstraints_as_functions>
183 This will export all the current type constraints as functions
184 into the caller's namespace. Right now, this is mostly used for
185 testing, but it might prove useful to others.
189 =head2 Type Constraint Constructors
191 The following functions are used to create type constraints.
192 They will then register the type constraints in a global store
193 where Moose can get to them if it needs to.
195 See the L<SYNOPOSIS> for an example of how to use these.
199 =item B<type ($name, $where_clause)>
201 This creates a base type, which has no parent.
203 =item B<subtype ($name, $parent, $where_clause)>
205 This creates a named subtype.
207 =item B<subtype ($parent, $where_clause)>
209 This creates an unnamed subtype and will return the type
210 constraint meta-object, which will be an instance of
211 L<Moose::Meta::TypeConstraint>.
215 This is just sugar for the type constraint construction syntax.
219 This is just sugar for the type constraint construction syntax.
223 =head2 Type Coercion Constructors
225 Type constraints can also contain type coercions as well. In most
226 cases Moose will run the type-coercion code first, followed by the
227 type constraint check. This feature should be used carefully as it
228 is very powerful and could easily take off a limb if you are not
231 See the L<SYNOPOSIS> for an example of how to use these.
239 This is just sugar for the type coercion construction syntax.
243 This is just sugar for the type coercion construction syntax.
249 All complex software has bugs lurking in it, and this module is no
250 exception. If you find a bug please either email me, or add the bug
255 Stevan Little E<lt>stevan@iinteractive.comE<gt>
257 =head1 COPYRIGHT AND LICENSE
259 Copyright 2006 by Infinity Interactive, Inc.
261 L<http://www.iinteractive.com>
263 This library is free software; you can redistribute it and/or modify
264 it under the same terms as Perl itself.