1 package Moose::Manual::Delta;
3 # ABSTRACT: Important Changes in Moose
11 This documents any important or noteworthy changes in Moose, with a
12 focus on things that affect backwards compatibility. This does duplicate data
13 from the F<Changes> file, but aims to provide more details and when possible
16 Besides helping keep up with changes, you can also use this document
17 for finding the lowest version of Moose that supported a given
18 feature. If you encounter a problem and have a solution but don't see
19 it documented here, or think we missed an important feature, please
26 =item All the Cookbook recipes have been renamed
28 We've given them all descriptive names, rather than numbers. This makes it
29 easier to talk about them, and eliminates the need to renumber recipes in
30 order to reorder them or delete one.
38 =item The parent of a union type is its components' nearest common ancestor
40 Previously, union types considered all of their component types their parent
41 types. This was incorrect because parent types are defined as types that must
42 be satisfied in order for the child type to be satisfied, but in a union,
43 validating as any parent type will validate against the entire union. This has
44 been changed to find the nearest common ancestor for all of its components. For
45 example, a union of "Int|ArrayRef[Int]" now has a parent of "Defined".
47 =item Union types consider all members in the C<is_subtype_of> and C<is_a_type_of> methods
49 Previously, a union type would report itself as being of a subtype of a type if
50 I<any> of its member types were subtypes of that type. This was incorrect
51 because any value that passes a subtype constraint must also pass a parent
52 constraint. This has changed so that I<all> of its member types must be a
53 subtype of the specified type.
55 =item Enum types now work with just one value
57 Previously, an C<enum> type needed to have two or more values. Nobody knew
60 =item Methods defined in UNIVERSAL now appear in the MOP
62 Any method introspection methods that look at methods from parent classes now
63 find methods defined in UNIVERSAL. This includes methods like C<<
64 $class->get_all_methods >> and C<< $class->find_method_by_name >>.
66 This also means that you can now apply method modifiers to these methods.
68 =item Hand-optimized type constraint code causes a deprecation warning
70 If you provide an optimized sub ref for a type constraint, this now causes a
71 deprecation warning. Typically, this comes from passing an C<optimize_as>
72 parameter to C<subtype>, but it could also happen if you create a
73 L<Moose::Meta::TypeConstraint> object directly.
75 Use the inlining feature (C<inline_as>) added in 2.0100 instead.
77 =item C<Class::Load::load_class> and C<is_class_loaded> have been removed
79 The C<Class::MOP::load_class> and C<Class::MOP::is_class_loaded> subroutines
80 are no longer documented, and will cause a deprecation warning in the
81 future. Moose now uses L<Class::Load> to provide this functionality, and you
90 =item Array and Hash native traits provide a C<shallow_clone> method
92 The Array and Hash native traits now provide a "shallow_clone" method, which
93 will return a reference to a new container with the same contents as the
94 attribute's reference.
102 =item Hand-optimized type constraint code is deprecated in favor of inlining
104 Moose allows you to provide a hand-optimized version of a type constraint's
105 subroutine reference. This version allows type constraints to generate inline
106 code, and you should use this inlining instead of providing a hand-optimized
107 subroutine reference.
109 This affects the C<optimize_as> sub exported by
110 L<Moose::Util::TypeConstraints>. Use C<inline_as> instead.
112 This will start warning in the 2.0300 release.
120 =item More useful type constraint error messages
122 If you have L<Devel::PartialDump> version 0.14 or higher installed, Moose's
123 type constraint error messages will use it to display the invalid value, rather
124 than just displaying it directly. This will generally be much more useful. For
125 instance, instead of this:
127 Attribute (foo) does not pass the type constraint because: Validation failed for 'ArrayRef[Int]' with value ARRAY(0x275eed8)
129 the error message will instead look like
131 Attribute (foo) does not pass the type constraint because: Validation failed for 'ArrayRef[Int]' with value [ "a" ]
133 Note that L<Devel::PartialDump> can't be made a direct dependency at the
134 moment, because it uses Moose itself, but we're considering options to make
143 =item Roles have their own default attribute metaclass
145 Previously, when a role was applied to a class, it would use the attribute
146 metaclass defined in the class when copying over the attributes in the role.
147 This was wrong, because for instance, using L<MooseX::FollowPBP> in the class
148 would end up renaming all of the accessors generated by the role, some of which
149 may be being called in the role, causing it to break. Roles now keep track of
150 their own attribute metaclass to use by default when being applied to a class
151 (defaulting to Moose::Meta::Attribute). This is modifiable using
152 L<Moose::Util::MetaRole> by passing the C<applied_attribute> key to the
153 C<role_metaroles> option, as in:
155 Moose::Util::MetaRole::apply_metaroles(
158 attribute => ['My::Meta::Role::Attribute'],
161 applied_attribute => ['My::Meta::Role::Attribute'],
165 =item Class::MOP has been folded into the Moose dist
167 Moose and Class::MOP are tightly related enough that they have always had to be
168 kept pretty closely in step in terms of versions. Making them into a single
169 dist should simplify the upgrade process for users, as it should no longer be
170 possible to upgrade one without the other and potentially cause issues. No
171 functionality has changed, and this should be entirely transparent.
173 =item Moose's conflict checking is more robust and useful
175 There are two parts to this. The most useful one right now is that Moose will
176 ship with a C<moose-outdated> script, which can be run at any point to list the
177 modules which are installed that conflict with the installed version of Moose.
178 After upgrading Moose, running C<moose-outdated | cpanm> should be sufficient
179 to ensure that all of the Moose extensions you use will continue to work.
181 The other part is that Moose's C<META.json> file will also specify the
182 conflicts under the C<x_conflicts> key. We are working with the Perl tool chain
183 developers to try to get conflicts support added to CPAN clients, and if/when
184 that happens, the metadata already exists, and so the conflict checking will
187 =item Most deprecated APIs/features are slated for removal in Moose 2.0200
189 Most of the deprecated APIs and features in Moose will start throwing an error
190 in Moose 2.0200. Some of the features will go away entirely, and some will
191 simply throw an error.
193 The things on the chopping block are:
197 =item * Old public methods in Class::MOP and Moose
199 This includes things like C<< Class::MOP::Class->get_attribute_map >>, C<<
200 Class::MOP::Class->construct_instance >>, and many others. These were
201 deprecated in L<Class::MOP> 0.80_01, released on April 5, 2009.
203 These methods will be removed entirely in Moose 2.0200.
205 =item * Old public functions in Class::MOP
207 This include C<Class::MOP::subname>, C<Class::MOP::in_global_destruction>, and
208 the C<Class::MOP::HAS_ISAREV> constant. The first two were deprecated in 0.84,
209 and the last in 0.80. Class::MOP 0.84 was released on May 12, 2009.
211 These functions will be removed entirely in Moose 2.0200.
213 =item * The C<alias> and C<excludes> option for role composition
215 These were renamed to C<-alias> and C<-excludes> in Moose 0.89, released on
218 Passing these will throw an error in Moose 2.0200.
220 =item * The old L<Moose::Util::MetaRole> API
222 This include the C<apply_metaclass_roles()> function, as well as passing the
223 C<for_class> or any key ending in C<_roles> to C<apply_metaroles()>. This was
224 deprecated in Moose 0.93_01, released on January 4, 2010.
226 These will all throw an error in Moose 2.0200.
228 =item * Passing plain lists to C<type()> or C<subtype()>
230 The old API for these functions allowed you to pass a plain list of parameter,
231 rather than a list of hash references (which is what C<as()>, C<where>,
232 etc. return). This was deprecated in Moose 0.71_01, released on February 22,
235 This will throw an error in Moose 2.0200.
237 =item * The Role subtype
239 This subtype was deprecated in Moose 0.84, released on June 26, 2009.
241 This will be removed entirely in Moose 2.0200.
251 =item * New release policy
253 As of the 2.0 release, Moose now has an official release and support policy,
254 documented in L<Moose::Manual::Support>. All API changes will now go through a
255 deprecation cycle of at least one year, after which the deprecated API can be
256 removed. Deprecations and removals will only happen in major releases.
258 In between major releases, we will still make minor releases to add new
259 features, fix bugs, update documentation, etc.
267 =item Configurable stacktraces
269 Classes which use the L<Moose::Error::Default> error class can now have
270 stacktraces disabled by setting the C<MOOSE_ERROR_STYLE> env var to C<croak>.
271 This is experimental, fairly incomplete, and won't work in all cases (because
272 Moose's error system in general is all of these things), but this should allow
273 for reducing at least some of the verbosity in most cases.
281 =item Native Delegations
283 In previous versions of Moose, the Native delegations were created as
284 closures. The generated code was often quite slow compared to doing the same
285 thing by hand. For example, the Array's push delegation ended up doing
288 push @{ $self->$reader() }, @_;
290 If the attribute was created without a reader, the C<$reader> sub reference
291 followed a very slow code path. Even with a reader, this is still slower than
294 Native delegations are now generated as inline code, just like other
295 accessors, so we can access the slot directly.
297 In addition, native traits now do proper constraint checking in all cases. In
298 particular, constraint checking has been improved for array and hash
299 references. Previously, only the I<contained> type (the C<Str> in
300 C<HashRef[Str]>) would be checked when a new value was added to the
301 collection. However, if there was a constraint that applied to the whole
302 value, this was never checked.
304 In addition, coercions are now called on the whole value.
306 The delegation methods now do more argument checking. All of the methods check
307 that a valid number of arguments were passed to the method. In addition, the
308 delegation methods check that the arguments are sane (array indexes, hash
309 keys, numbers, etc.) when applicable. We have tried to emulate the behavior of
310 Perl builtins as much as possible.
312 Finally, triggers are called whenever the value of the attribute is changed by
315 These changes are only likely to break code in a few cases.
317 The inlining code may or may not preserve the original reference when changes
318 are made. In some cases, methods which change the value may replace it
319 entirely. This will break tied values.
321 If you have a typed arrayref or hashref attribute where the type enforces a
322 constraint on the whole collection, this constraint will now be checked. It's
323 possible that code which previously ran without errors will now cause the
324 constraint to fail. However, presumably this is a good thing ;)
326 If you are passing invalid arguments to a delegation which were previously
327 being ignored, these calls will now fail.
329 If your code relied on the trigger only being called for a regular writer,
330 that may cause problems.
332 As always, you are encouraged to test before deploying the latest version of
335 =item Defaults is and default for String, Counter, and Bool
337 A few native traits (String, Counter, Bool) provide default values of "is" and
338 "default" when you created an attribute. Allowing them to provide these values
339 is now deprecated. Supply the value yourself when creating the attribute.
341 =item The C<meta> method
343 Moose and Class::MOP have been cleaned up internally enough to make the
344 C<meta> method that you get by default optional. C<use Moose> and
345 C<use Moose::Role> now can take an additional C<-meta_name> option, which
346 tells Moose what name to use when installing the C<meta> method. Passing
347 C<undef> to this option suppresses generation of the C<meta> method
348 entirely. This should be useful for users of modules which also use a C<meta>
349 method or function, such as L<Curses> or L<Rose::DB::Object>.
357 =item All deprecated features now warn
359 Previously, deprecation mostly consisted of simply saying "X is deprecated" in
360 the Changes file. We were not very consistent about actually warning. Now, all
361 deprecated features still present in Moose actually give a warning. The
362 warning is issued once per calling package. See L<Moose::Deprecated> for more
365 =item You cannot pass C<< coerce => 1 >> unless the attribute's type constraint has a coercion
367 Previously, this was accepted, and it sort of worked, except that if you
368 attempted to set the attribute after the object was created, you would get a
371 Now you will get a warning when you attempt to define the attribute.
373 =item C<no Moose>, C<no Moose::Role>, and C<no Moose::Exporter> no longer unimport strict and warnings
375 This change was made in 1.05, and has now been reverted. We don't know if the
376 user has explicitly loaded strict or warnings on their own, and unimporting
377 them is just broken in that case.
379 =item Reversed logic when defining which options can be changed
381 L<Moose::Meta::Attribute> now allows all options to be changed in an
382 overridden attribute. The previous behaviour required each option to be
383 whitelisted using the C<legal_options_for_inheritance> method. This method has
384 been removed, and there is a new method, C<illegal_options_for_inheritance>,
385 which can now be used to prevent certain options from being changeable.
387 In addition, we only throw an error if the illegal option is actually
388 changed. If the superclass didn't specify this option at all when defining the
389 attribute, the subclass version can still add it as an option.
391 Example of overriding this in an attribute trait:
393 package Bar::Meta::Attribute;
396 has 'my_illegal_option' => (
401 around illegal_options_for_inheritance => sub {
402 return ( shift->(@_), qw/my_illegal_option/ );
411 =item L<Moose::Object/BUILD> methods are now called when calling C<new_object>
413 Previously, C<BUILD> methods would only be called from C<Moose::Object::new>,
414 but now they are also called when constructing an object via
415 C<Moose::Meta::Class::new_object>. C<BUILD> methods are an inherent part of the
416 object construction process, and this should make C<< $meta->new_object >>
417 actually usable without forcing people to use C<< $meta->name->new >>.
419 =item C<no Moose>, C<no Moose::Role>, and C<no Moose::Exporter> now unimport strict and warnings
421 In the interest of having C<no Moose> clean up everything that C<use Moose>
422 does in the calling scope, C<no Moose> (as well as all other
423 L<Moose::Exporter>-using modules) now unimports strict and warnings.
425 =item Metaclass compatibility checking and fixing should be much more robust
427 The L<metaclass compatibility|Moose/METACLASS COMPATIBILITY AND MOOSE> checking
428 and fixing algorithms have been completely rewritten, in both Class::MOP and
429 Moose. This should resolve many confusing errors when dealing with non-Moose
430 inheritance and with custom metaclasses for things like attributes,
431 constructors, etc. For correct code, the only thing that should require a
432 change is that custom error metaclasses must now inherit from
433 L<Moose::Error::Default>.
441 =item Moose::Meta::TypeConstraint::Class is_subtype_of behavior
443 Earlier versions of L<is_subtype_of|Moose::Meta::TypeConstraint::Class/is_subtype_of>
444 would incorrectly return true when called with itself, its own TC name or
445 its class name as an argument. (i.e. $foo_tc->is_subtype_of('Foo') == 1) This
446 behavior was a caused by C<isa> being checked before the class name. The old
447 behavior can be accessed with L<is_type_of|Moose::Meta::TypeConstraint::Class/is_type_of>
455 =item Moose::Meta::Attribute::Native::Trait::Code no longer creates reader methods by default
457 Earlier versions of L<Moose::Meta::Attribute::Native::Trait::Code> created
458 read-only accessors for the attributes it's been applied to, even if you didn't
459 ask for it with C<< is => 'ro' >>. This incorrect behaviour has now been fixed.
467 =item Moose::Util add_method_modifier behavior
469 add_method_modifier (and subsequently the sugar functions Moose::before,
470 Moose::after, and Moose::around) can now accept arrayrefs, with the same
471 behavior as lists. Types other than arrayref and regexp result in an error.
475 =head1 0.93_01 and 0.94
479 =item Moose::Util::MetaRole API has changed
481 The C<apply_metaclass_roles> function is now called C<apply_metaroles>. The
482 way arguments are supplied has been changed to force you to distinguish
483 between metaroles applied to L<Moose::Meta::Class> (and helpers) versus
484 L<Moose::Meta::Role>.
486 The old API still works, but will warn in a future release, and eventually be
489 =item Moose::Meta::Role has real attributes
491 The attributes returned by L<Moose::Meta::Role> are now instances of the
492 L<Moose::Meta::Role::Attribute> class, instead of bare hash references.
494 =item "no Moose" now removes C<blessed> and C<confess>
496 Moose is now smart enough to know exactly what it exported, even when it
497 re-exports functions from other packages. When you unimport Moose, it will
498 remove these functions from your namespace unless you I<also> imported them
499 directly from their respective packages.
501 If you have a C<no Moose> in your code I<before> you call C<blessed> or
502 C<confess>, your code will break. You can either move the C<no Moose> call
503 later in your code, or explicitly import the relevant functions from the
504 packages that provide them.
506 =item L<Moose::Exporter> is smarter about unimporting re-exports
508 The change above comes from a general improvement to L<Moose::Exporter>. It
509 will now unimport any function it exports, even if that function is a
510 re-export from another package.
512 =item Attributes in roles can no longer override class attributes with "+foo"
514 Previously, this worked more or less accidentally, because role attributes
515 weren't objects. This was never documented, but a few MooseX modules took
518 =item The composition_class_roles attribute in L<Moose::Meta::Role> is now a method
520 This was done to make it possible for roles to alter the the list of
521 composition class roles by applying a method modifiers. Previously, this was
522 an attribute and MooseX modules override it. Since that no longer works, this
525 This I<should> be an attribute, so this may switch back to being an attribute
526 in the future if we can figure out how to make this work.
534 =item Calling $object->new() is no longer deprecated
536 We decided to undeprecate this. Now it just works.
538 =item Both C<get_method_map> and C<get_attribute_map> is deprecated
540 These metaclass methods were never meant to be public, and they are both now
541 deprecated. The work around if you still need the functionality they provided
542 is to iterate over the list of names manually.
544 my %fields = map { $_ => $meta->get_attribute($_) } $meta->get_attribute_list;
546 This was actually a change in L<Class::MOP>, but this version of Moose
547 requires a version of L<Class::MOP> that includes said change.
555 =item Added Native delegation for Code refs
557 See L<Moose::Meta::Attribute::Native::Trait::Code> for details.
559 =item Calling $object->new() is deprecated
561 Moose has long supported this, but it's never really been documented, and we
562 don't think this is a good practice. If you want to construct an object from
563 an existing object, you should provide some sort of alternate constructor like
564 C<< $object->clone >>.
566 Calling C<< $object->new >> now issues a warning, and will be an error in a
569 =item Moose no longer warns if you call C<make_immutable> for a class with mutable ancestors
571 While in theory this is a good thing to warn about, we found so many
572 exceptions to this that doing this properly became quite problematic.
580 =item New Native delegation methods from L<List::Util> and L<List::MoreUtils>
582 In particular, we now have C<reduce>, C<shuffle>, C<uniq>, and C<natatime>.
584 =item The Moose::Exporter with_caller feature is now deprecated
586 Use C<with_meta> instead. The C<with_caller> option will start warning in a
589 =item Moose now warns if you call C<make_immutable> for a class with mutable ancestors
591 This is dangerous because modifying a class after a subclass has been
592 immutabilized will lead to incorrect results in the subclass, due to inlining,
593 caching, etc. This occasionally happens accidentally, when a class loads one
594 of its subclasses in the middle of its class definition, so pointing out that
595 this may cause issues should be helpful. Metaclasses (classes that inherit
596 from L<Class::MOP::Object>) are currently exempt from this check, since at the
597 moment we aren't very consistent about which metaclasses we immutabilize.
599 =item C<enum> and C<duck_type> now take arrayrefs for all forms
601 Previously, calling these functions with a list would take the first element of
602 the list as the type constraint name, and use the remainder as the enum values
603 or method names. This makes the interface inconsistent with the anon-type forms
604 of these functions (which must take an arrayref), and a free-form list where
605 the first value is sometimes special is hard to validate (and harder to give
606 reasonable error messages for). These functions have been changed to take
607 arrayrefs in all their forms - so, C<< enum 'My::Type' => [qw(foo bar)] >> is
608 now the preferred way to create an enum type constraint. The old syntax still
609 works for now, but it will hopefully be deprecated and removed in a future
616 L<Moose::Meta::Attribute::Native> has been moved into the Moose core from
617 L<MooseX::AttributeHelpers>. Major changes include:
621 =item C<traits>, not C<metaclass>
623 Method providers are only available via traits.
625 =item C<handles>, not C<provides> or C<curries>
627 The C<provides> syntax was like core Moose C<< handles => HASHREF >>
628 syntax, but with the keys and values reversed. This was confusing,
629 and AttributeHelpers now uses C<< handles => HASHREF >> in a way that
630 should be intuitive to anyone already familiar with how it is used for
633 The C<curries> functionality provided by AttributeHelpers has been
634 generalized to apply to all cases of C<< handles => HASHREF >>, though
635 not every piece of functionality has been ported (currying with a
636 CODEREF is not supported).
638 =item C<empty> is now C<is_empty>, and means empty, not non-empty
640 Previously, the C<empty> method provided by Arrays and Hashes returned true if
641 the attribute was B<not> empty (no elements). Now it returns true if the
642 attribute B<is> empty. It was also renamed to C<is_empty>, to reflect this.
644 =item C<find> was renamed to C<first>, and C<first> and C<last> were removed
646 L<List::Util> refers to the functionality that we used to provide under C<find>
647 as L<first|List::Util/first>, so that will likely be more familiar (and will
648 fit in better if we decide to add more List::Util functions). C<first> and
649 C<last> were removed, since their functionality is easily duplicated with
652 =item Helpers that take a coderef of one argument now use C<$_>
654 Subroutines passed as the first argument to C<first>, C<map>, and C<grep> now
655 receive their argument in C<$_> rather than as a parameter to the subroutine.
656 Helpers that take a coderef of two or more arguments remain using the argument
657 list (there are technical limitations to using C<$a> and C<$b> like C<sort>
660 See L<Moose::Meta::Attribute::Native> for the new documentation.
664 The C<alias> and C<excludes> role parameters have been renamed to C<-alias>
665 and C<-excludes>. The old names still work, but new code should use the new
666 names, and eventually the old ones will be deprecated and removed.
670 C<< use Moose -metaclass => 'Foo' >> now does alias resolution, just like
671 C<-traits> (and the C<metaclass> and C<traits> options to C<has>).
673 Added two functions C<meta_class_alias> and C<meta_attribute_alias> to
674 L<Moose::Util>, to simplify aliasing metaclasses and metatraits. This is
675 a wrapper around the old
677 package Moose::Meta::Class::Custom::Trait::FooTrait;
678 sub register_implementation { 'My::Meta::Trait' }
684 When an attribute generates I<no> accessors, we now warn. This is to help
685 users who forget the C<is> option. If you really do not want any accessors,
686 you can use C<< is => 'bare' >>. You can maintain back compat with older
687 versions of Moose by using something like:
689 ($Moose::VERSION >= 0.84 ? is => 'bare' : ())
691 When an accessor overwrites an existing method, we now warn. To work around
692 this warning (if you really must have this behavior), you can explicitly
693 remove the method before creating it as an accessor:
697 __PACKAGE__->meta->remove_method('foo');
703 When an unknown option is passed to C<has>, we now warn. You can silence
704 the warning by fixing your code. :)
706 The C<Role> type has been deprecated. On its own, it was useless,
707 since it just checked C<< $object->can('does') >>. If you were using
708 it as a parent type, just call C<role_type('Role::Name')> to create an
709 appropriate type instead.
713 C<use Moose::Exporter;> now imports C<strict> and C<warnings> into packages
718 C<DEMOLISHALL> and C<DEMOLISH> now receive an argument indicating whether or
719 not we are in global destruction.
723 Type constraints no longer run coercions for a value that already matches the
724 constraint. This may affect some (arguably buggy) edge case coercions that
725 rely on side effects in the C<via> clause.
729 L<Moose::Exporter> now accepts the C<-metaclass> option for easily
730 overriding the metaclass (without L<metaclass>). This works for classes
735 Added a C<duck_type> sugar function to L<Moose::Util::TypeConstraints>
736 to make integration with non-Moose classes easier. It simply checks if
737 C<< $obj->can() >> a list of methods.
739 A number of methods (mostly inherited from L<Class::MOP>) have been
740 renamed with a leading underscore to indicate their internal-ness. The
741 old method names will still work for a while, but will warn that the
742 method has been renamed. In a few cases, the method will be removed
743 entirely in the future. This may affect MooseX authors who were using
748 Calling C<subtype> with a name as the only argument now throws an
749 exception. If you want an anonymous subtype do:
751 my $subtype = subtype as 'Foo';
753 This is related to the changes in version 0.71_01.
755 The C<is_needed> method in L<Moose::Meta::Method::Destructor> is now
756 only usable as a class method. Previously, it worked as a class or
757 object method, with a different internal implementation for each
760 The internals of making a class immutable changed a lot in Class::MOP
761 0.78_02, and Moose's internals have changed along with it. The
762 external C<< $metaclass->make_immutable >> method still works the same
767 A mutable class accepted C<< Foo->new(undef) >> without complaint,
768 while an immutable class would blow up with an unhelpful error. Now,
769 in both cases we throw a helpful error instead.
771 This "feature" was originally added to allow for cases such as this:
779 return My::Class->new($args);
781 But we decided this is a bad idea and a little too magical, because it
782 can easily mask real errors.
786 Calling C<type> or C<subtype> without the sugar helpers (C<as>,
787 C<where>, C<message>) is now deprecated.
789 As a side effect, this meant we ended up using Perl prototypes on
790 C<as>, and code like this will no longer work:
792 use Moose::Util::TypeConstraints;
793 use Declare::Constraints::Simple -All;
795 subtype 'ArrayOfInts'
797 => IsArrayRef(IsInt);
799 Instead it must be changed to this:
804 where => IsArrayRef(IsInt)
808 If you want to maintain backwards compat with older versions of Moose,
809 you must explicitly test Moose's C<VERSION>:
811 if ( Moose->VERSION < 0.71_01 ) {
812 subtype 'ArrayOfInts'
814 => IsArrayRef(IsInt);
820 where => IsArrayRef(IsInt)
827 We no longer pass the meta-attribute object as a final argument to
828 triggers. This actually changed for inlined code a while back, but the
829 non-inlined version and the docs were still out of date.
831 If by some chance you actually used this feature, the workaround is
832 simple. You fetch the attribute object from out of the C<$self>
833 that is passed as the first argument to trigger, like so:
839 my ( $self, $value ) = @_;
840 my $attr = $self->meta->find_attribute_by_name('foo');
848 If you created a subtype and passed a parent that Moose didn't know
849 about, it simply ignored the parent. Now it automatically creates the
850 parent as a class type. This may not be what you want, but is less
853 You could declare a name with subtype such as "Foo!Bar". Moose would
854 accept this allowed, but if you used it in a parameterized type such
855 as "ArrayRef[Foo!Bar]" it wouldn't work. We now do some vetting on
856 names created via the sugar functions, so that they can only contain
857 alphanumerics, ":", and ".".
861 Methods created via an attribute can now fulfill a C<requires>
862 declaration for a role. Honestly we don't know why Stevan didn't make
863 this work originally, he was just insane or something.
865 Stack traces from inlined code will now report the line and file as
866 being in your class, as opposed to in Moose guts.
870 When a class does not provide all of a role's required methods, the
871 error thrown now mentions all of the missing methods, as opposed to
872 just the first missing method.
874 Moose will no longer inline a constructor for your class unless it
875 inherits its constructor from Moose::Object, and will warn when it
876 doesn't inline. If you want to force inlining anyway, pass
877 C<< replace_constructor => 1 >> to C<make_immutable>.
879 If you want to get rid of the warning, pass C<< inline_constructor =>
884 Removed the (deprecated) C<make_immutable> keyword.
886 Removing an attribute from a class now also removes delegation
887 (C<handles>) methods installed for that attribute. This is correct
888 behavior, but if you were wrongly relying on it you might get bit.
892 Roles now add methods by calling C<add_method>, not
893 C<alias_method>. They make sure to always provide a method object,
894 which will be cloned internally. This means that it is now possible to
895 track the source of a method provided by a role, and even follow its
896 history through intermediate roles. This means that methods added by
897 a role now show up when looking at a class's method list/map.
899 Parameter and Union args are now sorted, this makes Int|Str the same
900 constraint as Str|Int. Also, incoming type constraint strings are
901 normalized to remove all whitespace differences. This is mostly for
902 internals and should not affect outside code.
904 L<Moose::Exporter> will no longer remove a subroutine that the
905 exporting package re-exports. Moose re-exports the Carp::confess
906 function, among others. The reasoning is that we cannot know whether
907 you have also explicitly imported those functions for your own use, so
908 we err on the safe side and always keep them.
912 C<Moose::init_meta> should now be called as a method.
914 New modules for extension writers, L<Moose::Exporter> and
915 L<Moose::Util::MetaRole>.
919 Implemented metaclass traits (and wrote a recipe for it):
921 use Moose -traits => 'Foo'
923 This should make writing small Moose extensions a little
928 Fixed C<coerce> to accept anon types just like C<subtype> can.
931 coerce $some_anon_type => from 'Str' => via { ... };
935 Added C<BUILDARGS>, a new step in C<< Moose::Object->new() >>.
939 Fixed how the C<< is => (ro|rw) >> works with custom defined
940 C<reader>, C<writer> and C<accessor> options. See the below table for
943 is => ro, writer => _foo # turns into (reader => foo, writer => _foo)
944 is => rw, writer => _foo # turns into (reader => foo, writer => _foo)
945 is => rw, accessor => _foo # turns into (accessor => _foo)
946 is => ro, accessor => _foo # error, accesor is rw
950 The C<before/around/after> method modifiers now support regexp
951 matching of method names. NOTE: this only works for classes, it is
952 currently not supported in roles, but, ... patches welcome.
954 The C<has> keyword for roles now accepts the same array ref form that
955 L<Moose>.pm does for classes.
957 A trigger on a read-only attribute is no longer an error, as it's
958 useful to trigger off of the constructor.
960 Subtypes of parameterizable types now are parameterizable types
965 Fixed issue where C<DEMOLISHALL> was eating the value in C<$@>, and so
966 not working correctly. It still kind of eats them, but so does vanilla
971 Inherited attributes may now be extended without restriction on the
972 type ('isa', 'does').
974 The entire set of Moose::Meta::TypeConstraint::* classes were
975 refactored in this release. If you were relying on their internals you
976 should test your code carefully.
980 Documenting the use of '+name' with attributes that come from recently
981 composed roles. It makes sense, people are using it, and so why not
982 just officially support it.
984 The C<< Moose::Meta::Class->create >> method now supports roles.
986 It is now possible to make anonymous enum types by passing C<enum> an
987 array reference instead of the C<< enum $name => @values >>.
991 Added the C<make_immutable> keyword as a shortcut to calling
992 C<make_immutable> on the meta object. This eventually got removed!
994 Made C<< init_arg => undef >> work in Moose. This means "do not accept
995 a constructor parameter for this attribute".
997 Type errors now use the provided message. Prior to this release they
1002 Moose is now a postmodern object system :)
1004 The Role system was completely refactored. It is 100% backwards
1005 compat, but the internals were totally changed. If you relied on the
1006 internals then you are advised to test carefully.
1008 Added method exclusion and aliasing for Roles in this release.
1010 Added the L<Moose::Util::TypeConstraints::OptimizedConstraints>
1013 Passing a list of values to an accessor (which is only expecting one
1014 value) used to be silently ignored, now it throws an error.
1018 Added parameterized types and did a pretty heavy refactoring of the
1019 type constraint system.
1021 Better framework extensibility and better support for "making your own
1024 =head1 0.25 or before
1026 Honestly, you shouldn't be using versions of Moose that are this old,
1027 so many bug fixes and speed improvements have been made you would be
1028 crazy to not upgrade.
1030 Also, I am tired of going through the Changelog so I am stopping here,
1031 if anyone would like to continue this please feel free.