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 $export (qw(type subtype as where message coerce from via find_type_constraint)) {
21 *{"${pkg}::${export}"} = \&{"${export}"};
27 sub find_type_constraint { $TYPES{$_[0]}->[1] }
29 sub _create_type_constraint {
30 my ($name, $parent, $check, $message) = @_;
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__',
42 $TYPES{$name} = [ $pkg_defined_in, $constraint ] if defined $name;
46 sub _install_type_coercions {
47 my ($type_name, $coercion_map) = @_;
48 my $type = find_type_constraint($type_name);
49 (!$type->has_coercion)
50 || confess "The type coercion for '$type_name' has already been registered";
51 my $type_coercion = Moose::Meta::TypeCoercion->new(
52 type_coercion_map => $coercion_map,
53 type_constraint => $type
55 $type->coercion($type_coercion);
58 sub export_type_contstraints_as_functions {
61 foreach my $constraint (keys %TYPES) {
62 *{"${pkg}::${constraint}"} = find_type_constraint($constraint)->_compiled_type_constraint;
70 my ($name, $check) = @_;
71 _create_type_constraint($name, undef, $check);
75 unshift @_ => undef if scalar @_ <= 2;
76 _create_type_constraint(@_);
80 my ($type_name, @coercion_map) = @_;
81 _install_type_coercions($type_name, \@coercion_map);
85 sub from ($) { $_[0] }
86 sub where (&) { $_[0] }
88 sub message (&) { $_[0] }
90 # define some basic types
92 type 'Any' => where { 1 };
94 subtype 'Value' => as 'Any' => where { !ref($_) };
95 subtype 'Ref' => as 'Any' => where { ref($_) };
97 subtype 'Int' => as 'Value' => where { Scalar::Util::looks_like_number($_) };
98 subtype 'Str' => as 'Value' => where { !Scalar::Util::looks_like_number($_) };
100 subtype 'ScalarRef' => as 'Ref' => where { ref($_) eq 'SCALAR' };
101 subtype 'ArrayRef' => as 'Ref' => where { ref($_) eq 'ARRAY' };
102 subtype 'HashRef' => as 'Ref' => where { ref($_) eq 'HASH' };
103 subtype 'CodeRef' => as 'Ref' => where { ref($_) eq 'CODE' };
104 subtype 'RegexpRef' => as 'Ref' => where { ref($_) eq 'Regexp' };
107 # blessed(qr/.../) returns true,.. how odd
108 subtype 'Object' => as 'Ref' => where { blessed($_) && blessed($_) ne 'Regexp' };
118 Moose::Util::TypeConstraints - Type constraint system for Moose
122 use Moose::Util::TypeConstraints;
124 type Num => where { Scalar::Util::looks_like_number($_) };
130 subtype NaturalLessThanTen
133 => message { "This number ($_) is not less than ten!" };
141 This module provides Moose with the ability to create type contraints
142 to be are used in both attribute definitions and for method argument
145 =head2 Important Caveat
147 This is B<NOT> a type system for Perl 5. These are type constraints,
148 and they are not used by Moose unless you tell it to. No type
149 inference is performed, expression are not typed, etc. etc. etc.
151 This is simply a means of creating small constraint functions which
152 can be used to simplify your own type-checking code.
154 =head2 Default Type Constraints
156 This module also provides a simple hierarchy for Perl 5 types, this
157 could probably use some work, but it works for me at the moment.
171 Suggestions for improvement are welcome.
175 =head2 Type Constraint Registry
179 =item B<find_type_constraint ($type_name)>
181 This function can be used to locate a specific type constraint
182 meta-object. What you do with it from there is up to you :)
184 =item B<export_type_contstraints_as_functions>
186 This will export all the current type constraints as functions
187 into the caller's namespace. Right now, this is mostly used for
188 testing, but it might prove useful to others.
192 =head2 Type Constraint Constructors
194 The following functions are used to create type constraints.
195 They will then register the type constraints in a global store
196 where Moose can get to them if it needs to.
198 See the L<SYNOPOSIS> for an example of how to use these.
202 =item B<type ($name, $where_clause)>
204 This creates a base type, which has no parent.
206 =item B<subtype ($name, $parent, $where_clause, ?$message)>
208 This creates a named subtype.
210 =item B<subtype ($parent, $where_clause, ?$message)>
212 This creates an unnamed subtype and will return the type
213 constraint meta-object, which will be an instance of
214 L<Moose::Meta::TypeConstraint>.
218 This is just sugar for the type constraint construction syntax.
222 This is just sugar for the type constraint construction syntax.
226 This is just sugar for the type constraint construction syntax.
230 =head2 Type Coercion Constructors
232 Type constraints can also contain type coercions as well. In most
233 cases Moose will run the type-coercion code first, followed by the
234 type constraint check. This feature should be used carefully as it
235 is very powerful and could easily take off a limb if you are not
238 See the L<SYNOPOSIS> for an example of how to use these.
246 This is just sugar for the type coercion construction syntax.
250 This is just sugar for the type coercion construction syntax.
256 All complex software has bugs lurking in it, and this module is no
257 exception. If you find a bug please either email me, or add the bug
262 Stevan Little E<lt>stevan@iinteractive.comE<gt>
264 =head1 COPYRIGHT AND LICENSE
266 Copyright 2006 by Infinity Interactive, Inc.
268 L<http://www.iinteractive.com>
270 This library is free software; you can redistribute it and/or modify
271 it under the same terms as Perl itself.