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' };
119 subtype 'Role' => as 'Object' => where { $_->can('does') };
129 Moose::Util::TypeConstraints - Type constraint system for Moose
133 use Moose::Util::TypeConstraints;
135 type Num => where { Scalar::Util::looks_like_number($_) };
141 subtype NaturalLessThanTen
144 => message { "This number ($_) is not less than ten!" };
152 This module provides Moose with the ability to create type contraints
153 to be are used in both attribute definitions and for method argument
156 =head2 Important Caveat
158 This is B<NOT> a type system for Perl 5. These are type constraints,
159 and they are not used by Moose unless you tell it to. No type
160 inference is performed, expression are not typed, etc. etc. etc.
162 This is simply a means of creating small constraint functions which
163 can be used to simplify your own type-checking code.
165 =head2 Default Type Constraints
167 This module also provides a simple hierarchy for Perl 5 types, this
168 could probably use some work, but it works for me at the moment.
183 Suggestions for improvement are welcome.
187 =head2 Type Constraint Registry
191 =item B<find_type_constraint ($type_name)>
193 This function can be used to locate a specific type constraint
194 meta-object. What you do with it from there is up to you :)
196 =item B<export_type_contstraints_as_functions>
198 This will export all the current type constraints as functions
199 into the caller's namespace. Right now, this is mostly used for
200 testing, but it might prove useful to others.
204 =head2 Type Constraint Constructors
206 The following functions are used to create type constraints.
207 They will then register the type constraints in a global store
208 where Moose can get to them if it needs to.
210 See the L<SYNOPOSIS> for an example of how to use these.
214 =item B<type ($name, $where_clause)>
216 This creates a base type, which has no parent.
218 =item B<subtype ($name, $parent, $where_clause, ?$message)>
220 This creates a named subtype.
222 =item B<subtype ($parent, $where_clause, ?$message)>
224 This creates an unnamed subtype and will return the type
225 constraint meta-object, which will be an instance of
226 L<Moose::Meta::TypeConstraint>.
230 This is just sugar for the type constraint construction syntax.
234 This is just sugar for the type constraint construction syntax.
238 This is just sugar for the type constraint construction syntax.
242 =head2 Type Coercion Constructors
244 Type constraints can also contain type coercions as well. In most
245 cases Moose will run the type-coercion code first, followed by the
246 type constraint check. This feature should be used carefully as it
247 is very powerful and could easily take off a limb if you are not
250 See the L<SYNOPOSIS> for an example of how to use these.
258 This is just sugar for the type coercion construction syntax.
262 This is just sugar for the type coercion construction syntax.
268 All complex software has bugs lurking in it, and this module is no
269 exception. If you find a bug please either email me, or add the bug
274 Stevan Little E<lt>stevan@iinteractive.comE<gt>
276 =head1 COPYRIGHT AND LICENSE
278 Copyright 2006 by Infinity Interactive, Inc.
280 L<http://www.iinteractive.com>
282 This library is free software; you can redistribute it and/or modify
283 it under the same terms as Perl itself.