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 create_type_constraint_union {
73 my (@type_constraint_names) = @_;
74 return Moose::Meta::TypeConstraint->union(
76 find_type_constraint($_)
77 } @type_constraint_names
81 sub export_type_contstraints_as_functions {
84 foreach my $constraint (keys %TYPES) {
85 *{"${pkg}::${constraint}"} = find_type_constraint($constraint)->_compiled_type_constraint;
93 my ($name, $check) = @_;
94 _create_type_constraint($name, undef, $check);
98 unshift @_ => undef if scalar @_ <= 2;
99 _create_type_constraint(@_);
103 my ($type_name, @coercion_map) = @_;
104 _install_type_coercions($type_name, \@coercion_map);
108 sub from ($) { $_[0] }
109 sub where (&) { $_[0] }
110 sub via (&) { $_[0] }
111 sub message (&) { $_[0] }
113 # define some basic types
115 type 'Any' => where { 1 }; # meta-type including all
116 type 'Item' => where { 1 }; # base-type
118 subtype 'Undef' => as 'Item' => where { !defined($_) };
119 subtype 'Defined' => as 'Item' => where { defined($_) };
121 subtype 'Bool' => as 'Item' => where { !defined($_) || $_ eq "" || "$_" eq '1' || "$_" eq '0' };
123 subtype 'Value' => as 'Defined' => where { !ref($_) };
124 subtype 'Ref' => as 'Defined' => where { ref($_) };
126 subtype 'Str' => as 'Value' => where { 1 };
128 subtype 'Num' => as 'Value' => where { Scalar::Util::looks_like_number($_) };
129 subtype 'Int' => as 'Num' => where { "$_" =~ /^-?[0-9]+$/ };
131 subtype 'ScalarRef' => as 'Ref' => where { ref($_) eq 'SCALAR' };
132 subtype 'ArrayRef' => as 'Ref' => where { ref($_) eq 'ARRAY' };
133 subtype 'HashRef' => as 'Ref' => where { ref($_) eq 'HASH' };
134 subtype 'CodeRef' => as 'Ref' => where { ref($_) eq 'CODE' };
135 subtype 'RegexpRef' => as 'Ref' => where { ref($_) eq 'Regexp' };
138 # blessed(qr/.../) returns true,.. how odd
139 subtype 'Object' => as 'Ref' => where { blessed($_) && blessed($_) ne 'Regexp' };
141 subtype 'Role' => as 'Object' => where { $_->can('does') };
151 Moose::Util::TypeConstraints - Type constraint system for Moose
155 use Moose::Util::TypeConstraints;
157 type Num => where { Scalar::Util::looks_like_number($_) };
163 subtype NaturalLessThanTen
166 => message { "This number ($_) is not less than ten!" };
174 This module provides Moose with the ability to create type contraints
175 to be are used in both attribute definitions and for method argument
178 =head2 Important Caveat
180 This is B<NOT> a type system for Perl 5. These are type constraints,
181 and they are not used by Moose unless you tell it to. No type
182 inference is performed, expression are not typed, etc. etc. etc.
184 This is simply a means of creating small constraint functions which
185 can be used to simplify your own type-checking code.
187 =head2 Default Type Constraints
189 This module also provides a simple hierarchy for Perl 5 types, this
190 could probably use some work, but it works for me at the moment.
210 Suggestions for improvement are welcome.
214 =head2 Type Constraint Registry
218 =item B<find_type_constraint ($type_name)>
220 This function can be used to locate a specific type constraint
221 meta-object. What you do with it from there is up to you :)
223 =item B<create_type_constraint_union (@type_constraint_names)>
225 Given a list of C<@type_constraint_names>, this will return a
226 B<Moose::Meta::TypeConstraint::Union> instance.
228 =item B<export_type_contstraints_as_functions>
230 This will export all the current type constraints as functions
231 into the caller's namespace. Right now, this is mostly used for
232 testing, but it might prove useful to others.
236 =head2 Type Constraint Constructors
238 The following functions are used to create type constraints.
239 They will then register the type constraints in a global store
240 where Moose can get to them if it needs to.
242 See the L<SYNOPOSIS> for an example of how to use these.
246 =item B<type ($name, $where_clause)>
248 This creates a base type, which has no parent.
250 =item B<subtype ($name, $parent, $where_clause, ?$message)>
252 This creates a named subtype.
254 =item B<subtype ($parent, $where_clause, ?$message)>
256 This creates an unnamed subtype and will return the type
257 constraint meta-object, which will be an instance of
258 L<Moose::Meta::TypeConstraint>.
262 This is just sugar for the type constraint construction syntax.
266 This is just sugar for the type constraint construction syntax.
270 This is just sugar for the type constraint construction syntax.
274 =head2 Type Coercion Constructors
276 Type constraints can also contain type coercions as well. In most
277 cases Moose will run the type-coercion code first, followed by the
278 type constraint check. This feature should be used carefully as it
279 is very powerful and could easily take off a limb if you are not
282 See the L<SYNOPOSIS> for an example of how to use these.
290 This is just sugar for the type coercion construction syntax.
294 This is just sugar for the type coercion construction syntax.
300 All complex software has bugs lurking in it, and this module is no
301 exception. If you find a bug please either email me, or add the bug
306 Stevan Little E<lt>stevan@iinteractive.comE<gt>
308 =head1 COPYRIGHT AND LICENSE
310 Copyright 2006 by Infinity Interactive, Inc.
312 L<http://www.iinteractive.com>
314 This library is free software; you can redistribute it and/or modify
315 it under the same terms as Perl itself.