2 package Moose::Util::TypeConstraints;
8 use Scalar::Util 'blessed';
12 our $VERSION = '0.12';
13 our $AUTHORITY = 'cpan:STEVAN';
15 use Moose::Meta::TypeConstraint;
16 use Moose::Meta::TypeCoercion;
19 type subtype as where message optimize_as
25 Sub::Exporter::setup_exporter({
27 groups => { default => [':all'] }
33 # loop through the exports ...
34 foreach my $name (@exports) {
36 if (defined &{$class . '::' . $name}) {
37 my $keyword = \&{$class . '::' . $name};
39 # make sure it is from Moose
40 my $pkg_name = eval { svref_2object($keyword)->GV->STASH->NAME };
42 next if $pkg_name ne 'Moose::Util::TypeConstraints';
44 # and if it is from Moose then undef the slot
45 delete ${$class . '::'}{$name};
52 sub find_type_constraint ($) {
53 return $TYPES{$_[0]}->[1]
54 if exists $TYPES{$_[0]};
58 sub _dump_type_constraints {
60 Data::Dumper::Dumper(\%TYPES);
63 sub _create_type_constraint ($$$;$$) {
68 my ($message, $optimized);
70 $message = $_->{message} if exists $_->{message};
71 $optimized = $_->{optimized} if exists $_->{optimized};
74 my $pkg_defined_in = scalar(caller(1));
75 ($TYPES{$name}->[0] eq $pkg_defined_in)
76 || confess "The type constraint '$name' has already been created "
77 if defined $name && exists $TYPES{$name};
78 $parent = find_type_constraint($parent) if defined $parent;
79 my $constraint = Moose::Meta::TypeConstraint->new(
80 name => $name || '__ANON__',
84 optimized => $optimized,
86 $TYPES{$name} = [ $pkg_defined_in, $constraint ] if defined $name;
90 sub _install_type_coercions ($$) {
91 my ($type_name, $coercion_map) = @_;
92 my $type = find_type_constraint($type_name);
93 (!$type->has_coercion)
94 || confess "The type coercion for '$type_name' has already been registered";
95 my $type_coercion = Moose::Meta::TypeCoercion->new(
96 type_coercion_map => $coercion_map,
97 type_constraint => $type
99 $type->coercion($type_coercion);
102 sub create_type_constraint_union (@) {
103 my (@type_constraint_names) = @_;
104 return Moose::Meta::TypeConstraint->union(
106 find_type_constraint($_)
107 } @type_constraint_names
111 sub export_type_contstraints_as_functions {
114 foreach my $constraint (keys %TYPES) {
115 *{"${pkg}::${constraint}"} = find_type_constraint($constraint)->_compiled_type_constraint;
119 sub list_all_type_constraints { keys %TYPES }
125 splice(@_, 1, 0, undef);
126 goto &_create_type_constraint;
129 sub subtype ($$;$$$) {
130 unshift @_ => undef if scalar @_ <= 2;
131 goto &_create_type_constraint;
135 my ($type_name, @coercion_map) = @_;
136 _install_type_coercions($type_name, \@coercion_map);
140 sub from ($) { $_[0] }
141 sub where (&) { $_[0] }
142 sub via (&) { $_[0] }
144 sub message (&) { +{ message => $_[0] } }
145 sub optimize_as (&) { +{ optimized => $_[0] } }
148 my ($type_name, @values) = @_;
149 (scalar @values >= 2)
150 || confess "You must have at least two values to enumerate through";
151 my $regexp = join '|' => @values;
152 _create_type_constraint(
155 sub { qr/^$regexp$/i }
159 # define some basic types
161 type 'Any' => where { 1 }; # meta-type including all
162 type 'Item' => where { 1 }; # base-type
164 subtype 'Undef' => as 'Item' => where { !defined($_) };
165 subtype 'Defined' => as 'Item' => where { defined($_) };
169 => where { !defined($_) || $_ eq "" || "$_" eq '1' || "$_" eq '0' };
173 => where { !ref($_) }
174 => optimize_as { defined($_[0]) && !ref($_[0]) };
179 => optimize_as { ref($_[0]) };
184 => optimize_as { defined($_[0]) && !ref($_[0]) };
188 => where { Scalar::Util::looks_like_number($_) }
189 => optimize_as { !ref($_[0]) && Scalar::Util::looks_like_number($_[0]) };
193 => where { "$_" =~ /^-?[0-9]+$/ }
194 => optimize_as { defined($_[0]) && !ref($_[0]) && $_[0] =~ /^-?[0-9]+$/ };
196 subtype 'ScalarRef' => as 'Ref' => where { ref($_) eq 'SCALAR' } => optimize_as { ref($_[0]) eq 'SCALAR' };
197 subtype 'ArrayRef' => as 'Ref' => where { ref($_) eq 'ARRAY' } => optimize_as { ref($_[0]) eq 'ARRAY' };
198 subtype 'HashRef' => as 'Ref' => where { ref($_) eq 'HASH' } => optimize_as { ref($_[0]) eq 'HASH' };
199 subtype 'CodeRef' => as 'Ref' => where { ref($_) eq 'CODE' } => optimize_as { ref($_[0]) eq 'CODE' };
200 subtype 'RegexpRef' => as 'Ref' => where { ref($_) eq 'Regexp' } => optimize_as { ref($_[0]) eq 'Regexp' };
201 subtype 'GlobRef' => as 'Ref' => where { ref($_) eq 'GLOB' } => optimize_as { ref($_[0]) eq 'GLOB' };
204 # scalar filehandles are GLOB refs,
205 # but a GLOB ref is not always a filehandle
208 => where { Scalar::Util::openhandle($_) }
209 => optimize_as { ref($_[0]) eq 'GLOB' && Scalar::Util::openhandle($_[0]) };
212 # blessed(qr/.../) returns true,.. how odd
215 => where { blessed($_) && blessed($_) ne 'Regexp' }
216 => optimize_as { blessed($_[0]) && blessed($_[0]) ne 'Regexp' };
220 => where { $_->can('does') }
221 => optimize_as { blessed($_[0]) && $_[0]->can('does') };
231 Moose::Util::TypeConstraints - Type constraint system for Moose
235 use Moose::Util::TypeConstraints;
237 type 'Num' => where { Scalar::Util::looks_like_number($_) };
243 subtype 'NaturalLessThanTen'
246 => message { "This number ($_) is not less than ten!" };
252 enum 'RGBColors' => qw(red green blue);
256 This module provides Moose with the ability to create custom type
257 contraints to be used in attribute definition.
259 =head2 Important Caveat
261 This is B<NOT> a type system for Perl 5. These are type constraints,
262 and they are not used by Moose unless you tell it to. No type
263 inference is performed, expression are not typed, etc. etc. etc.
265 This is simply a means of creating small constraint functions which
266 can be used to simplify your own type-checking code.
268 =head2 Slightly Less Important Caveat
270 It is almost always a good idea to quote your type and subtype names.
271 This is to prevent perl from trying to execute the call as an indirect
272 object call. This issue only seems to come up when you have a subtype
273 the same name as a valid class, but when the issue does arise it tends
274 to be quite annoying to debug.
276 So for instance, this:
278 subtype DateTime => as Object => where { $_->isa('DateTime') };
280 will I<Just Work>, while this:
283 subtype DateTime => as Object => where { $_->isa('DateTime') };
285 will fail silently and cause many headaches. The simple way to solve
286 this, as well as future proof your subtypes from classes which have
287 yet to have been created yet, is to simply do this:
290 subtype 'DateTime' => as 'Object' => where { $_->isa('DateTime') };
292 =head2 Default Type Constraints
294 This module also provides a simple hierarchy for Perl 5 types, this
295 could probably use some work, but it works for me at the moment.
317 Suggestions for improvement are welcome.
319 B<NOTE:> The C<Undef> type constraint does not work correctly
320 in every occasion, please use it sparringly.
322 =head2 Use with Other Constraint Modules
324 This module should play fairly nicely with other constraint
325 modules with only some slight tweaking. The C<where> clause
326 in types is expected to be a C<CODE> reference which checks
327 it's first argument and returns a bool. Since most constraint
328 modules work in a similar way, it should be simple to adapt
329 them to work with Moose.
331 For instance, this is how you could use it with
332 L<Declare::Constraints::Simple> to declare a completely new type.
334 type 'HashOfArrayOfObjects'
337 -values => IsArrayRef( IsObject ));
339 For more examples see the F<t/204_example_w_DCS.t> test file.
341 Here is an example of using L<Test::Deep> and it's non-test
342 related C<eq_deeply> function.
344 type 'ArrayOfHashOfBarsAndRandomNumbers'
347 array_each(subhashof({
349 random_number => ignore()
353 For a complete example see the F<t/205_example_w_TestDeep.t>
358 =head2 Type Constraint Registry
362 =item B<find_type_constraint ($type_name)>
364 This function can be used to locate a specific type constraint
365 meta-object. What you do with it from there is up to you :)
367 =item B<create_type_constraint_union (@type_constraint_names)>
369 Given a list of C<@type_constraint_names>, this will return a
370 B<Moose::Meta::TypeConstraint::Union> instance.
372 =item B<export_type_contstraints_as_functions>
374 This will export all the current type constraints as functions
375 into the caller's namespace. Right now, this is mostly used for
376 testing, but it might prove useful to others.
378 =item B<list_all_type_constraints>
380 This will return a list of type constraint names, you can then
381 fetch them using C<find_type_constraint ($type_name)> if you
386 =head2 Type Constraint Constructors
388 The following functions are used to create type constraints.
389 They will then register the type constraints in a global store
390 where Moose can get to them if it needs to.
392 See the L<SYNOPOSIS> for an example of how to use these.
396 =item B<type ($name, $where_clause)>
398 This creates a base type, which has no parent.
400 =item B<subtype ($name, $parent, $where_clause, ?$message)>
402 This creates a named subtype.
404 =item B<subtype ($parent, $where_clause, ?$message)>
406 This creates an unnamed subtype and will return the type
407 constraint meta-object, which will be an instance of
408 L<Moose::Meta::TypeConstraint>.
410 =item B<enum ($name, @values)>
412 This will create a basic subtype for a given set of strings.
413 The resulting constraint will be a subtype of C<Str> and
414 will match any of the items in C<@values>. See the L<SYNOPSIS>
415 for a simple example.
417 B<NOTE:> This is not a true proper enum type, it is simple
418 a convient constraint builder.
422 This is just sugar for the type constraint construction syntax.
426 This is just sugar for the type constraint construction syntax.
430 This is just sugar for the type constraint construction syntax.
434 This can be used to define a "hand optimized" version of your
435 type constraint which can be used to avoid traversing a subtype
436 constraint heirarchy.
438 B<NOTE:> You should only use this if you know what you are doing,
439 all the built in types use this, so your subtypes (assuming they
440 are shallow) will not likely need to use this.
444 =head2 Type Coercion Constructors
446 Type constraints can also contain type coercions as well. If you
447 ask your accessor too coerce, the Moose will run the type-coercion
448 code first, followed by the type constraint check. This feature
449 should be used carefully as it is very powerful and could easily
450 take off a limb if you are not careful.
452 See the L<SYNOPOSIS> for an example of how to use these.
460 This is just sugar for the type coercion construction syntax.
464 This is just sugar for the type coercion construction syntax.
468 =head2 Namespace Management
474 This will remove all the type constraint keywords from the
475 calling class namespace.
481 All complex software has bugs lurking in it, and this module is no
482 exception. If you find a bug please either email me, or add the bug
487 Stevan Little E<lt>stevan@iinteractive.comE<gt>
489 =head1 COPYRIGHT AND LICENSE
491 Copyright 2006, 2007 by Infinity Interactive, Inc.
493 L<http://www.iinteractive.com>
495 This library is free software; you can redistribute it and/or modify
496 it under the same terms as Perl itself.