6 MooseX::Types - Organise your Moose types in libraries
10 use Moose::Util::TypeConstraints;
11 use MooseX::Types::TypeDecorator;
12 use MooseX::Types::Base ();
13 use MooseX::Types::Util qw( filter_tags );
14 use MooseX::Types::UndefinedType;
15 use MooseX::Types::CheckedUtilExports ();
16 use Carp::Clan qw( ^MooseX::Types );
18 use Scalar::Util 'reftype';
20 use namespace::clean -except => [qw( meta )];
23 our $VERSION = '0.11';
24 my $UndefMsg = q{Action for type '%s' not yet defined in library '%s'};
28 =head2 Library Definition
32 # predeclare our own types
35 PositiveInt NegativeInt
36 ArrayRefOfPositiveInt ArrayRefOfAtLeastThreeNegativeInts
37 LotsOfInnerConstraints StrOrArrayRef
40 # import builtin types
41 use MooseX::Types::Moose qw/Int HashRef/;
47 message { "Int is not larger than 0" };
52 message { "Int is not smaller than 0" };
59 # with parameterized constraints.
61 subtype ArrayRefOfPositiveInt,
62 as ArrayRef[PositiveInt];
64 subtype ArrayRefOfAtLeastThreeNegativeInts,
65 as ArrayRef[NegativeInt],
66 where { scalar(@$_) > 2 };
68 subtype LotsOfInnerConstraints,
69 as ArrayRef[ArrayRef[HashRef[Int]]];
71 # with TypeConstraint Unions
73 subtype StrOrArrayRef,
76 class_type 'DateTime';
80 via { DateTime->new(%$_) };
88 use MyLibrary qw( PositiveInt NegativeInt );
90 # use the exported constants as type names
102 print "positive\n" if is_PositiveInt($value);
103 print "negative\n" if is_NegativeInt($value);
105 # coerce the value, NegativeInt doesn't have a coercion
106 # helper, since it didn't define any coercions.
107 $value = to_PositiveInt($value) or die "Cannot coerce";
114 The types provided with L<Moose> are by design global. This package helps
115 you to organise and selectively import your own and the built-in types in
116 libraries. As a nice side effect, it catches typos at compile-time too.
118 However, the main reason for this module is to provide an easy way to not
119 have conflicts with your type names, since the internal fully qualified
120 names of the types will be prefixed with the library's name.
122 This module will also provide you with some helper functions to make it
123 easier to use Moose types in your code.
125 String type names will produce a syntax error, unless it's for a C<class_type>
126 or C<role_type> declared within the library.
128 =head1 TYPE HANDLER FUNCTIONS
132 A constant with the name of your type. It contains the type's fully
133 qualified name. Takes no value, as all constants.
137 This handler takes a value and tests if it is a valid value for this
138 C<$type>. It will return true or false.
142 A handler that will take a value and coerce it into the C<$type>. It will
143 return a false value if the type could not be coerced.
145 B<Important Note>: This handler will only be exported for types that can
146 do type coercion. This has the advantage that a coercion to a type that
147 cannot hasn't defined any coercions will lead to a compile-time error.
149 =head1 LIBRARY DEFINITION
151 A MooseX::Types is just a normal Perl module. Unlike Moose
152 itself, it does not install C<use strict> and C<use warnings> in your
153 class by default, so this is up to you.
155 The only thing a library is required to do is
157 use MooseX::Types -declare => \@types;
159 with C<@types> being a list of types you wish to define in this library.
160 This line will install a proper base class in your package as well as the
161 full set of L<handlers|/"TYPE HANDLER FUNCTIONS"> for your declared
162 types. It will then hand control over to L<Moose::Util::TypeConstraints>'
163 C<import> method to export the functions you will need to declare your
166 If you want to use Moose' built-in types (e.g. for subtyping) you will
169 use MooseX::Types::Moose @types;
171 to import the helpers from the shipped L<MooseX::Types::Moose>
172 library which can export all types that come with Moose.
174 You will have to define coercions for your types or your library won't
175 export a L</to_$type> coercion helper for it.
177 Note that you currently cannot define types containing C<::>, since
178 exporting would be a problem.
180 You also don't need to use C<warnings> and C<strict>, since the
181 definition of a library automatically exports those.
185 You can import the L<"type helpers"|/"TYPE HANDLER FUNCTIONS"> of a
186 library by C<use>ing it with a list of types to import as arguments. If
187 you want all of them, use the C<:all> tag. For example:
189 use MyLibrary ':all';
190 use MyOtherLibrary qw( TypeA TypeB );
192 MooseX::Types comes with a library of Moose' built-in types called
193 L<MooseX::Types::Moose>.
195 The exporting mechanism is, since version 0.5, implemented via a wrapper
196 around L<Sub::Exporter>. This means you can do something like this:
198 use MyLibrary TypeA => { -as => 'MyTypeA' },
199 TypeB => { -as => 'MyTypeB' };
201 =head1 WRAPPING A LIBRARY
203 You can define your own wrapper subclasses to manipulate the behaviour
204 of a set of library exports. Here is an example:
209 use base 'MooseX::Types::Wrapper';
211 sub coercion_export_generator {
213 my $code = $class->next::method(@_);
215 my $value = $code->(@_);
216 warn "Coercion returned undef!"
217 unless defined $value;
224 This class wraps the coercion generator (e.g., C<to_Int()>) and warns
225 if a coercion returned an undefined value. You can wrap any library
230 use MyWrapper MyLibrary => [qw( Foo Bar )],
231 Moose => [qw( Str Int )];
236 The C<Moose> library name is a special shortcut for
237 L<MooseX::Types::Moose>.
239 =head2 Generator methods you can overload
243 =item type_export_generator( $short, $full )
245 Creates a closure returning the type's L<Moose::Meta::TypeConstraint>
248 =item check_export_generator( $short, $full, $undef_message )
250 This creates the closure used to test if a value is valid for this type.
252 =item coercion_export_generator( $short, $full, $undef_message )
254 This is the closure that's doing coercions.
258 =head2 Provided Parameters
264 The short, exported name of the type.
268 The fully qualified name of this type as L<Moose> knows it.
272 A message that will be thrown when type functionality is used but the
273 type does not yet exist.
277 =head1 RECURSIVE SUBTYPES
279 As of version 0.08, L<Moose::Types> has experimental support for Recursive
280 subtypes. This will allow:
282 subtype Tree() => as HashRef[Str|Tree];
284 Which validates things like:
287 {key=>{subkey1=>'value', subkey2=>'value'}}
289 And so on. This feature is new and there may be lurking bugs so don't be afraid
290 to hunt me down with patches and test cases if you have trouble.
292 =head1 NOTES REGARDING TYPE UNIONS
294 L<MooseX::Types> uses L<MooseX::Types::TypeDecorator> to do some overloading
295 which generally allows you to easily create union types:
297 subtype StrOrArrayRef,
300 As with parameterized constrains, this overloading extends to modules using the
301 types you define in a type library.
304 use MooseX::Types::Moose qw(HashRef Int);
306 has 'attr' => (isa=>HashRef|Int);
308 And everything should just work as you'd think.
314 Installs the L<MooseX::Types::Base> class into the caller and
315 exports types according to the specification described in
316 L</"LIBRARY DEFINITION">. This will continue to
317 L<Moose::Util::TypeConstraints>' C<import> method to export helper
318 functions you will need to declare your types.
323 my ($class, %args) = @_;
326 # everyone should want this
330 # inject base class into new library
332 unshift @{ $callee . '::ISA' }, 'MooseX::Types::Base';
335 # generate predeclared type helpers
336 if (my @orig_declare = @{ $args{ -declare } || [] }) {
337 my ($tags, $declare) = filter_tags @orig_declare;
340 for my $type (@$declare) {
342 croak "Cannot create a type containing '::' ($type) at the moment"
345 # add type to library and remember to export
346 $callee->add_type($type);
347 push @to_export, $type;
350 $callee->import({ -full => 1, -into => $callee }, @to_export);
353 # run type constraints import
354 Moose::Util::TypeConstraints->import({ into => $callee });
356 # override some with versions that check for syntax errors
357 MooseX::Types::CheckedUtilExports->import({ into => $callee });
362 =head2 type_export_generator
364 Generate a type export, e.g. C<Int()>. This will return either a
365 L<Moose::Meta::TypeConstraint> object, or alternatively a
366 L<MooseX::Types::UndefinedType> object if the type was not
371 sub type_export_generator {
372 my ($class, $type, $name) = @_;
374 ## Return an anonymous subroutine that will generate the proxied type
375 ## constraint for you.
377 return subname $name => sub {
378 my $type_constraint = $class->create_base_type_constraint($name);
380 if(defined(my $params = shift @_)) {
381 ## We currently only allow a TC to accept a single, ArrayRef
382 ## parameter, as in HashRef[Int], where [Int] is what's inside the
384 if(reftype $params eq 'ARRAY') {
385 $type_constraint = $class->create_arged_type_constraint($name, @$params);
386 } elsif(!defined $type_constraint) {
387 croak "Syntax error in type definition (did you forget a comma"
390 croak "Argument must be an ArrayRef to create a parameterized "
391 . "type, Eg.: ${type}[Int]. Got: ".ref($params)."."
395 $type_constraint = defined($type_constraint) ? $type_constraint
396 : MooseX::Types::UndefinedType->new($name);
398 my $type_decorator = $class->create_type_decorator($type_constraint);
400 ## If there are additional args, that means it's probably stuff that
401 ## needs to be returned to the subtype. Not an ideal solution here but
402 ## doesn't seem to cause trouble.
405 return ($type_decorator, @_);
407 return $type_decorator;
412 =head2 create_arged_type_constraint ($name, @args)
414 Given a String $name with @args find the matching typeconstraint and parameterize
419 sub create_arged_type_constraint {
420 my ($class, $name, @args) = @_;
421 my $type_constraint = Moose::Util::TypeConstraints::find_or_create_type_constraint("$name");
422 return $type_constraint->parameterize(@args);
425 =head2 create_base_type_constraint ($name)
427 Given a String $name, find the matching typeconstraint.
431 sub create_base_type_constraint {
432 my ($class, $name) = @_;
433 return find_type_constraint($name);
436 =head2 create_type_decorator ($type_constraint)
438 Given a $type_constraint, return a lightweight L<MooseX::Types::TypeDecorator>
443 sub create_type_decorator {
444 my ($class, $type_constraint) = @_;
445 return MooseX::Types::TypeDecorator->new($type_constraint);
448 =head2 coercion_export_generator
450 This generates a coercion handler function, e.g. C<to_Int($value)>.
454 sub coercion_export_generator {
455 my ($class, $type, $full, $undef_msg) = @_;
459 # we need a type object
460 my $tobj = find_type_constraint($full) or croak $undef_msg;
461 my $return = $tobj->coerce($value);
463 # non-successful coercion returns false
464 return unless $tobj->check($return);
470 =head2 check_export_generator
472 Generates a constraint check closure, e.g. C<is_Int($value)>.
476 sub check_export_generator {
477 my ($class, $type, $full, $undef_msg) = @_;
481 # we need a type object
482 my $tobj = find_type_constraint($full) or croak $undef_msg;
484 return $tobj->check($value);
490 The following are lists of gotcha's and their workarounds for developers coming
491 from the standard string based type constraint names
495 A library makes the types quasi-unique by prefixing their names with (by
496 default) the library package name. If you're only using the type handler
497 functions provided by MooseX::Types, you shouldn't ever have to use
498 a type's actual full name.
500 =head2 Argument separation ('=>' versus ',')
502 The Perlop manpage has this to say about the '=>' operator: "The => operator is
503 a synonym for the comma, but forces any word (consisting entirely of word
504 characters) to its left to be interpreted as a string (as of 5.001). This
505 includes words that might otherwise be considered a constant or function call."
507 Due to this stringification, the following will NOT work as you might think:
509 subtype StrOrArrayRef => as Str|ArrayRef;
511 The 'StrOrArrayRef' will have it's stringification activated this causes the
512 subtype to not be created. Since the bareword type constraints are not strings
513 you really should not try to treat them that way. You will have to use the ','
514 operator instead. The author's of this package realize that all the L<Moose>
515 documention and examples nearly uniformly use the '=>' version of the comma
516 operator and this could be an issue if you are converting code.
518 Patches welcome for discussion.
520 =head2 Compatibility with Sub::Exporter
522 If you want to use L<Sub::Exporter> with a Type Library, you need to make sure
523 you export all the type constraints declared AS WELL AS any additional export
524 targets. For example if you do:
526 package TypeAndSubExporter; {
528 use MooseX::Types::Moose qw(Str);
529 use MooseX::Types -declare => [qw(MyStr)];
530 use Sub::Exporter -setup => { exports => [ qw(something) ] };
542 use TypeAndSubExporter qw(MyStr);
545 You'll get a '"MyStr" is not exported by the TypeAndSubExporter module' error.
546 Upi can workaround by:
548 - use Sub::Exporter -setup => { exports => [ qw(something) ] };
549 + use Sub::Exporter -setup => { exports => [ qw(something MyStr) ] };
551 This is a workaround and I am exploring how to make these modules work better
552 together. I realize this workaround will lead a lot of duplication in your
553 export declarations and will be onerous for large type libraries. Patches and
554 detailed test cases welcome. See the tests directory for a start on this.
559 L<Moose::Util::TypeConstraints>,
560 L<MooseX::Types::Moose>,
563 =head1 AUTHOR AND COPYRIGHT
565 Robert 'phaylon' Sedlacek C<E<lt>rs@474.atE<gt>>, with many thanks to
566 the C<#moose> cabal on C<irc.perl.org>.
568 Additional features by John Napiorkowski (jnapiorkowski) <jjnapiork@cpan.org>.
572 This program is free software; you can redistribute it and/or modify
573 it under the same terms as perl itself.