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 The parent of a union type is its components' nearest common ancestor
28 Previously, union types considered all of their component types their parent
29 types. This was incorrect because parent types are defined as types that must
30 be satisfied in order for the child type to be satisfied, but in a union,
31 validating as any parent type will validate against the entire union. This has
32 been changed to find the nearest common ancestor for all of its components. For
33 example, a union of "Int|ArrayRef[Int]" now has a parent of "Defined".
35 =item Union types consider all members in the C<is_subtype_of> and C<is_a_type_of> methods
37 Previously, a union type would report itself as being of a subtype of a type if
38 I<any> of its member types were subtypes of that type. This was incorrect
39 because any value that passes a subtype constraint must also pass a parent
40 constraint. This has changed so that I<all> of its member types must be a
41 subtype of the specified type.
43 =item Enum types now work with just one value
45 Previously, an C<enum> type needed to have two or more values. Nobody knew
48 =item Methods defined in UNIVERSAL now appear in the MOP
50 Any method introspection methods that look at methods from parent classes now
51 find methods defined in UNIVERSAL. This includes methods like C<<
52 $class->get_all_methods >> and C<< $class->find_method_by_name >>.
54 This also means that you can now apply method modifiers to these methods.
56 =item Hand-optimized type constraint code causes a deprecation warning
58 If you provide an optimized sub ref for a type constraint, this now causes a
59 deprecation warning. Typically, this comes from passing an C<optimize_as>
60 parameter to C<subtype>, but it could also happen if you create a
61 L<Moose::Meta::TypeConstraint> object directly.
63 Use the inlining feature (C<inline_as>) added in 2.0100 instead.
65 =item C<Class::Load::load_class> and C<is_class_loaded> have been removed
67 The C<Class::MOP::load_class> and C<Class::MOP::is_class_loaded> subroutines
68 are no longer documented, and will cause a deprecation warning in the
69 future. Moose now uses L<Class::Load> to provide this functionality, and you
78 =item Array and Hash native traits provide a C<shallow_clone> method
80 The Array and Hash native traits now provide a "shallow_clone" method, which
81 will return a reference to a new container with the same contents as the
82 attribute's reference.
90 =item Hand-optimized type constraint code is deprecated in favor of inlining
92 Moose allows you to provide a hand-optimized version of a type constraint's
93 subroutine reference. This version allows type constraints to generate inline
94 code, and you should use this inlining instead of providing a hand-optimized
97 This affects the C<optimize_as> sub exported by
98 L<Moose::Util::TypeConstraints>. Use C<inline_as> instead.
100 This will start warning in the 2.0300 release.
108 =item More useful type constraint error messages
110 If you have L<Devel::PartialDump> version 0.14 or higher installed, Moose's
111 type constraint error messages will use it to display the invalid value, rather
112 than just displaying it directly. This will generally be much more useful. For
113 instance, instead of this:
115 Attribute (foo) does not pass the type constraint because: Validation failed for 'ArrayRef[Int]' with value ARRAY(0x275eed8)
117 the error message will instead look like
119 Attribute (foo) does not pass the type constraint because: Validation failed for 'ArrayRef[Int]' with value [ "a" ]
121 Note that L<Devel::PartialDump> can't be made a direct dependency at the
122 moment, because it uses Moose itself, but we're considering options to make
131 =item Roles have their own default attribute metaclass
133 Previously, when a role was applied to a class, it would use the attribute
134 metaclass defined in the class when copying over the attributes in the role.
135 This was wrong, because for instance, using L<MooseX::FollowPBP> in the class
136 would end up renaming all of the accessors generated by the role, some of which
137 may be being called in the role, causing it to break. Roles now keep track of
138 their own attribute metaclass to use by default when being applied to a class
139 (defaulting to Moose::Meta::Attribute). This is modifiable using
140 L<Moose::Util::MetaRole> by passing the C<applied_attribute> key to the
141 C<role_metaroles> option, as in:
143 Moose::Util::MetaRole::apply_metaroles(
146 attribute => ['My::Meta::Role::Attribute'],
149 applied_attribute => ['My::Meta::Role::Attribute'],
153 =item Class::MOP has been folded into the Moose dist
155 Moose and Class::MOP are tightly related enough that they have always had to be
156 kept pretty closely in step in terms of versions. Making them into a single
157 dist should simplify the upgrade process for users, as it should no longer be
158 possible to upgrade one without the other and potentially cause issues. No
159 functionality has changed, and this should be entirely transparent.
161 =item Moose's conflict checking is more robust and useful
163 There are two parts to this. The most useful one right now is that Moose will
164 ship with a C<moose-outdated> script, which can be run at any point to list the
165 modules which are installed that conflict with the installed version of Moose.
166 After upgrading Moose, running C<moose-outdated | cpanm> should be sufficient
167 to ensure that all of the Moose extensions you use will continue to work.
169 The other part is that Moose's C<META.json> file will also specify the
170 conflicts under the C<x_conflicts> key. We are working with the Perl tool chain
171 developers to try to get conflicts support added to CPAN clients, and if/when
172 that happens, the metadata already exists, and so the conflict checking will
175 =item Most deprecated APIs/features are slated for removal in Moose 2.0200
177 Most of the deprecated APIs and features in Moose will start throwing an error
178 in Moose 2.0200. Some of the features will go away entirely, and some will
179 simply throw an error.
181 The things on the chopping block are:
185 =item * Old public methods in Class::MOP and Moose
187 This includes things like C<< Class::MOP::Class->get_attribute_map >>, C<<
188 Class::MOP::Class->construct_instance >>, and many others. These were
189 deprecated in L<Class::MOP> 0.80_01, released on April 5, 2009.
191 These methods will be removed entirely in Moose 2.0200.
193 =item * Old public functions in Class::MOP
195 This include C<Class::MOP::subname>, C<Class::MOP::in_global_destruction>, and
196 the C<Class::MOP::HAS_ISAREV> constant. The first two were deprecated in 0.84,
197 and the last in 0.80. Class::MOP 0.84 was released on May 12, 2009.
199 These functions will be removed entirely in Moose 2.0200.
201 =item * The C<alias> and C<excludes> option for role composition
203 These were renamed to C<-alias> and C<-excludes> in Moose 0.89, released on
206 Passing these will throw an error in Moose 2.0200.
208 =item * The old L<Moose::Util::MetaRole> API
210 This include the C<apply_metaclass_roles()> function, as well as passing the
211 C<for_class> or any key ending in C<_roles> to C<apply_metaroles()>. This was
212 deprecated in Moose 0.93_01, released on January 4, 2010.
214 These will all throw an error in Moose 2.0200.
216 =item * Passing plain lists to C<type()> or C<subtype()>
218 The old API for these functions allowed you to pass a plain list of parameter,
219 rather than a list of hash references (which is what C<as()>, C<where>,
220 etc. return). This was deprecated in Moose 0.71_01, released on February 22,
223 This will throw an error in Moose 2.0200.
225 =item * The Role subtype
227 This subtype was deprecated in Moose 0.84, released on June 26, 2009.
229 This will be removed entirely in Moose 2.0200.
239 =item * New release policy
241 As of the 2.0 release, Moose now has an official release and support policy,
242 documented in L<Moose::Manual::Support>. All API changes will now go through a
243 deprecation cycle of at least one year, after which the deprecated API can be
244 removed. Deprecations and removals will only happen in major releases.
246 In between major releases, we will still make minor releases to add new
247 features, fix bugs, update documentation, etc.
255 =item Configurable stacktraces
257 Classes which use the L<Moose::Error::Default> error class can now have
258 stacktraces disabled by setting the C<MOOSE_ERROR_STYLE> env var to C<croak>.
259 This is experimental, fairly incomplete, and won't work in all cases (because
260 Moose's error system in general is all of these things), but this should allow
261 for reducing at least some of the verbosity in most cases.
269 =item Native Delegations
271 In previous versions of Moose, the Native delegations were created as
272 closures. The generated code was often quite slow compared to doing the same
273 thing by hand. For example, the Array's push delegation ended up doing
276 push @{ $self->$reader() }, @_;
278 If the attribute was created without a reader, the C<$reader> sub reference
279 followed a very slow code path. Even with a reader, this is still slower than
282 Native delegations are now generated as inline code, just like other
283 accessors, so we can access the slot directly.
285 In addition, native traits now do proper constraint checking in all cases. In
286 particular, constraint checking has been improved for array and hash
287 references. Previously, only the I<contained> type (the C<Str> in
288 C<HashRef[Str]>) would be checked when a new value was added to the
289 collection. However, if there was a constraint that applied to the whole
290 value, this was never checked.
292 In addition, coercions are now called on the whole value.
294 The delegation methods now do more argument checking. All of the methods check
295 that a valid number of arguments were passed to the method. In addition, the
296 delegation methods check that the arguments are sane (array indexes, hash
297 keys, numbers, etc.) when applicable. We have tried to emulate the behavior of
298 Perl builtins as much as possible.
300 Finally, triggers are called whenever the value of the attribute is changed by
303 These changes are only likely to break code in a few cases.
305 The inlining code may or may not preserve the original reference when changes
306 are made. In some cases, methods which change the value may replace it
307 entirely. This will break tied values.
309 If you have a typed arrayref or hashref attribute where the type enforces a
310 constraint on the whole collection, this constraint will now be checked. It's
311 possible that code which previously ran without errors will now cause the
312 constraint to fail. However, presumably this is a good thing ;)
314 If you are passing invalid arguments to a delegation which were previously
315 being ignored, these calls will now fail.
317 If your code relied on the trigger only being called for a regular writer,
318 that may cause problems.
320 As always, you are encouraged to test before deploying the latest version of
323 =item Defaults is and default for String, Counter, and Bool
325 A few native traits (String, Counter, Bool) provide default values of "is" and
326 "default" when you created an attribute. Allowing them to provide these values
327 is now deprecated. Supply the value yourself when creating the attribute.
329 =item The C<meta> method
331 Moose and Class::MOP have been cleaned up internally enough to make the
332 C<meta> method that you get by default optional. C<use Moose> and
333 C<use Moose::Role> now can take an additional C<-meta_name> option, which
334 tells Moose what name to use when installing the C<meta> method. Passing
335 C<undef> to this option suppresses generation of the C<meta> method
336 entirely. This should be useful for users of modules which also use a C<meta>
337 method or function, such as L<Curses> or L<Rose::DB::Object>.
345 =item All deprecated features now warn
347 Previously, deprecation mostly consisted of simply saying "X is deprecated" in
348 the Changes file. We were not very consistent about actually warning. Now, all
349 deprecated features still present in Moose actually give a warning. The
350 warning is issued once per calling package. See L<Moose::Deprecated> for more
353 =item You cannot pass C<< coerce => 1 >> unless the attribute's type constraint has a coercion
355 Previously, this was accepted, and it sort of worked, except that if you
356 attempted to set the attribute after the object was created, you would get a
359 Now you will get a warning when you attempt to define the attribute.
361 =item C<no Moose>, C<no Moose::Role>, and C<no Moose::Exporter> no longer unimport strict and warnings
363 This change was made in 1.05, and has now been reverted. We don't know if the
364 user has explicitly loaded strict or warnings on their own, and unimporting
365 them is just broken in that case.
367 =item Reversed logic when defining which options can be changed
369 L<Moose::Meta::Attribute> now allows all options to be changed in an
370 overridden attribute. The previous behaviour required each option to be
371 whitelisted using the C<legal_options_for_inheritance> method. This method has
372 been removed, and there is a new method, C<illegal_options_for_inheritance>,
373 which can now be used to prevent certain options from being changeable.
375 In addition, we only throw an error if the illegal option is actually
376 changed. If the superclass didn't specify this option at all when defining the
377 attribute, the subclass version can still add it as an option.
379 Example of overriding this in an attribute trait:
381 package Bar::Meta::Attribute;
384 has 'my_illegal_option' => (
389 around illegal_options_for_inheritance => sub {
390 return ( shift->(@_), qw/my_illegal_option/ );
399 =item L<Moose::Object/BUILD> methods are now called when calling C<new_object>
401 Previously, C<BUILD> methods would only be called from C<Moose::Object::new>,
402 but now they are also called when constructing an object via
403 C<Moose::Meta::Class::new_object>. C<BUILD> methods are an inherent part of the
404 object construction process, and this should make C<< $meta->new_object >>
405 actually usable without forcing people to use C<< $meta->name->new >>.
407 =item C<no Moose>, C<no Moose::Role>, and C<no Moose::Exporter> now unimport strict and warnings
409 In the interest of having C<no Moose> clean up everything that C<use Moose>
410 does in the calling scope, C<no Moose> (as well as all other
411 L<Moose::Exporter>-using modules) now unimports strict and warnings.
413 =item Metaclass compatibility checking and fixing should be much more robust
415 The L<metaclass compatibility|Moose/METACLASS COMPATIBILITY AND MOOSE> checking
416 and fixing algorithms have been completely rewritten, in both Class::MOP and
417 Moose. This should resolve many confusing errors when dealing with non-Moose
418 inheritance and with custom metaclasses for things like attributes,
419 constructors, etc. For correct code, the only thing that should require a
420 change is that custom error metaclasses must now inherit from
421 L<Moose::Error::Default>.
429 =item Moose::Meta::TypeConstraint::Class is_subtype_of behavior
431 Earlier versions of L<is_subtype_of|Moose::Meta::TypeConstraint::Class/is_subtype_of>
432 would incorrectly return true when called with itself, its own TC name or
433 its class name as an argument. (i.e. $foo_tc->is_subtype_of('Foo') == 1) This
434 behavior was a caused by C<isa> being checked before the class name. The old
435 behavior can be accessed with L<is_type_of|Moose::Meta::TypeConstraint::Class/is_type_of>
443 =item Moose::Meta::Attribute::Native::Trait::Code no longer creates reader methods by default
445 Earlier versions of L<Moose::Meta::Attribute::Native::Trait::Code> created
446 read-only accessors for the attributes it's been applied to, even if you didn't
447 ask for it with C<< is => 'ro' >>. This incorrect behaviour has now been fixed.
455 =item Moose::Util add_method_modifier behavior
457 add_method_modifier (and subsequently the sugar functions Moose::before,
458 Moose::after, and Moose::around) can now accept arrayrefs, with the same
459 behavior as lists. Types other than arrayref and regexp result in an error.
463 =head1 0.93_01 and 0.94
467 =item Moose::Util::MetaRole API has changed
469 The C<apply_metaclass_roles> function is now called C<apply_metaroles>. The
470 way arguments are supplied has been changed to force you to distinguish
471 between metaroles applied to L<Moose::Meta::Class> (and helpers) versus
472 L<Moose::Meta::Role>.
474 The old API still works, but will warn in a future release, and eventually be
477 =item Moose::Meta::Role has real attributes
479 The attributes returned by L<Moose::Meta::Role> are now instances of the
480 L<Moose::Meta::Role::Attribute> class, instead of bare hash references.
482 =item "no Moose" now removes C<blessed> and C<confess>
484 Moose is now smart enough to know exactly what it exported, even when it
485 re-exports functions from other packages. When you unimport Moose, it will
486 remove these functions from your namespace unless you I<also> imported them
487 directly from their respective packages.
489 If you have a C<no Moose> in your code I<before> you call C<blessed> or
490 C<confess>, your code will break. You can either move the C<no Moose> call
491 later in your code, or explicitly import the relevant functions from the
492 packages that provide them.
494 =item L<Moose::Exporter> is smarter about unimporting re-exports
496 The change above comes from a general improvement to L<Moose::Exporter>. It
497 will now unimport any function it exports, even if that function is a
498 re-export from another package.
500 =item Attributes in roles can no longer override class attributes with "+foo"
502 Previously, this worked more or less accidentally, because role attributes
503 weren't objects. This was never documented, but a few MooseX modules took
506 =item The composition_class_roles attribute in L<Moose::Meta::Role> is now a method
508 This was done to make it possible for roles to alter the the list of
509 composition class roles by applying a method modifiers. Previously, this was
510 an attribute and MooseX modules override it. Since that no longer works, this
513 This I<should> be an attribute, so this may switch back to being an attribute
514 in the future if we can figure out how to make this work.
522 =item Calling $object->new() is no longer deprecated
524 We decided to undeprecate this. Now it just works.
526 =item Both C<get_method_map> and C<get_attribute_map> is deprecated
528 These metaclass methods were never meant to be public, and they are both now
529 deprecated. The work around if you still need the functionality they provided
530 is to iterate over the list of names manually.
532 my %fields = map { $_ => $meta->get_attribute($_) } $meta->get_attribute_list;
534 This was actually a change in L<Class::MOP>, but this version of Moose
535 requires a version of L<Class::MOP> that includes said change.
543 =item Added Native delegation for Code refs
545 See L<Moose::Meta::Attribute::Native::Trait::Code> for details.
547 =item Calling $object->new() is deprecated
549 Moose has long supported this, but it's never really been documented, and we
550 don't think this is a good practice. If you want to construct an object from
551 an existing object, you should provide some sort of alternate constructor like
552 C<< $object->clone >>.
554 Calling C<< $object->new >> now issues a warning, and will be an error in a
557 =item Moose no longer warns if you call C<make_immutable> for a class with mutable ancestors
559 While in theory this is a good thing to warn about, we found so many
560 exceptions to this that doing this properly became quite problematic.
568 =item New Native delegation methods from L<List::Util> and L<List::MoreUtils>
570 In particular, we now have C<reduce>, C<shuffle>, C<uniq>, and C<natatime>.
572 =item The Moose::Exporter with_caller feature is now deprecated
574 Use C<with_meta> instead. The C<with_caller> option will start warning in a
577 =item Moose now warns if you call C<make_immutable> for a class with mutable ancestors
579 This is dangerous because modifying a class after a subclass has been
580 immutabilized will lead to incorrect results in the subclass, due to inlining,
581 caching, etc. This occasionally happens accidentally, when a class loads one
582 of its subclasses in the middle of its class definition, so pointing out that
583 this may cause issues should be helpful. Metaclasses (classes that inherit
584 from L<Class::MOP::Object>) are currently exempt from this check, since at the
585 moment we aren't very consistent about which metaclasses we immutabilize.
587 =item C<enum> and C<duck_type> now take arrayrefs for all forms
589 Previously, calling these functions with a list would take the first element of
590 the list as the type constraint name, and use the remainder as the enum values
591 or method names. This makes the interface inconsistent with the anon-type forms
592 of these functions (which must take an arrayref), and a free-form list where
593 the first value is sometimes special is hard to validate (and harder to give
594 reasonable error messages for). These functions have been changed to take
595 arrayrefs in all their forms - so, C<< enum 'My::Type' => [qw(foo bar)] >> is
596 now the preferred way to create an enum type constraint. The old syntax still
597 works for now, but it will hopefully be deprecated and removed in a future
604 L<Moose::Meta::Attribute::Native> has been moved into the Moose core from
605 L<MooseX::AttributeHelpers>. Major changes include:
609 =item C<traits>, not C<metaclass>
611 Method providers are only available via traits.
613 =item C<handles>, not C<provides> or C<curries>
615 The C<provides> syntax was like core Moose C<< handles => HASHREF >>
616 syntax, but with the keys and values reversed. This was confusing,
617 and AttributeHelpers now uses C<< handles => HASHREF >> in a way that
618 should be intuitive to anyone already familiar with how it is used for
621 The C<curries> functionality provided by AttributeHelpers has been
622 generalized to apply to all cases of C<< handles => HASHREF >>, though
623 not every piece of functionality has been ported (currying with a
624 CODEREF is not supported).
626 =item C<empty> is now C<is_empty>, and means empty, not non-empty
628 Previously, the C<empty> method provided by Arrays and Hashes returned true if
629 the attribute was B<not> empty (no elements). Now it returns true if the
630 attribute B<is> empty. It was also renamed to C<is_empty>, to reflect this.
632 =item C<find> was renamed to C<first>, and C<first> and C<last> were removed
634 L<List::Util> refers to the functionality that we used to provide under C<find>
635 as L<first|List::Util/first>, so that will likely be more familiar (and will
636 fit in better if we decide to add more List::Util functions). C<first> and
637 C<last> were removed, since their functionality is easily duplicated with
640 =item Helpers that take a coderef of one argument now use C<$_>
642 Subroutines passed as the first argument to C<first>, C<map>, and C<grep> now
643 receive their argument in C<$_> rather than as a parameter to the subroutine.
644 Helpers that take a coderef of two or more arguments remain using the argument
645 list (there are technical limitations to using C<$a> and C<$b> like C<sort>
648 See L<Moose::Meta::Attribute::Native> for the new documentation.
652 The C<alias> and C<excludes> role parameters have been renamed to C<-alias>
653 and C<-excludes>. The old names still work, but new code should use the new
654 names, and eventually the old ones will be deprecated and removed.
658 C<< use Moose -metaclass => 'Foo' >> now does alias resolution, just like
659 C<-traits> (and the C<metaclass> and C<traits> options to C<has>).
661 Added two functions C<meta_class_alias> and C<meta_attribute_alias> to
662 L<Moose::Util>, to simplify aliasing metaclasses and metatraits. This is
663 a wrapper around the old
665 package Moose::Meta::Class::Custom::Trait::FooTrait;
666 sub register_implementation { 'My::Meta::Trait' }
672 When an attribute generates I<no> accessors, we now warn. This is to help
673 users who forget the C<is> option. If you really do not want any accessors,
674 you can use C<< is => 'bare' >>. You can maintain back compat with older
675 versions of Moose by using something like:
677 ($Moose::VERSION >= 0.84 ? is => 'bare' : ())
679 When an accessor overwrites an existing method, we now warn. To work around
680 this warning (if you really must have this behavior), you can explicitly
681 remove the method before creating it as an accessor:
685 __PACKAGE__->meta->remove_method('foo');
691 When an unknown option is passed to C<has>, we now warn. You can silence
692 the warning by fixing your code. :)
694 The C<Role> type has been deprecated. On its own, it was useless,
695 since it just checked C<< $object->can('does') >>. If you were using
696 it as a parent type, just call C<role_type('Role::Name')> to create an
697 appropriate type instead.
701 C<use Moose::Exporter;> now imports C<strict> and C<warnings> into packages
706 C<DEMOLISHALL> and C<DEMOLISH> now receive an argument indicating whether or
707 not we are in global destruction.
711 Type constraints no longer run coercions for a value that already matches the
712 constraint. This may affect some (arguably buggy) edge case coercions that
713 rely on side effects in the C<via> clause.
717 L<Moose::Exporter> now accepts the C<-metaclass> option for easily
718 overriding the metaclass (without L<metaclass>). This works for classes
723 Added a C<duck_type> sugar function to L<Moose::Util::TypeConstraints>
724 to make integration with non-Moose classes easier. It simply checks if
725 C<< $obj->can() >> a list of methods.
727 A number of methods (mostly inherited from L<Class::MOP>) have been
728 renamed with a leading underscore to indicate their internal-ness. The
729 old method names will still work for a while, but will warn that the
730 method has been renamed. In a few cases, the method will be removed
731 entirely in the future. This may affect MooseX authors who were using
736 Calling C<subtype> with a name as the only argument now throws an
737 exception. If you want an anonymous subtype do:
739 my $subtype = subtype as 'Foo';
741 This is related to the changes in version 0.71_01.
743 The C<is_needed> method in L<Moose::Meta::Method::Destructor> is now
744 only usable as a class method. Previously, it worked as a class or
745 object method, with a different internal implementation for each
748 The internals of making a class immutable changed a lot in Class::MOP
749 0.78_02, and Moose's internals have changed along with it. The
750 external C<< $metaclass->make_immutable >> method still works the same
755 A mutable class accepted C<< Foo->new(undef) >> without complaint,
756 while an immutable class would blow up with an unhelpful error. Now,
757 in both cases we throw a helpful error instead.
759 This "feature" was originally added to allow for cases such as this:
767 return My::Class->new($args);
769 But we decided this is a bad idea and a little too magical, because it
770 can easily mask real errors.
774 Calling C<type> or C<subtype> without the sugar helpers (C<as>,
775 C<where>, C<message>) is now deprecated.
777 As a side effect, this meant we ended up using Perl prototypes on
778 C<as>, and code like this will no longer work:
780 use Moose::Util::TypeConstraints;
781 use Declare::Constraints::Simple -All;
783 subtype 'ArrayOfInts'
785 => IsArrayRef(IsInt);
787 Instead it must be changed to this:
792 where => IsArrayRef(IsInt)
796 If you want to maintain backwards compat with older versions of Moose,
797 you must explicitly test Moose's C<VERSION>:
799 if ( Moose->VERSION < 0.71_01 ) {
800 subtype 'ArrayOfInts'
802 => IsArrayRef(IsInt);
808 where => IsArrayRef(IsInt)
815 We no longer pass the meta-attribute object as a final argument to
816 triggers. This actually changed for inlined code a while back, but the
817 non-inlined version and the docs were still out of date.
819 If by some chance you actually used this feature, the workaround is
820 simple. You fetch the attribute object from out of the C<$self>
821 that is passed as the first argument to trigger, like so:
827 my ( $self, $value ) = @_;
828 my $attr = $self->meta->find_attribute_by_name('foo');
836 If you created a subtype and passed a parent that Moose didn't know
837 about, it simply ignored the parent. Now it automatically creates the
838 parent as a class type. This may not be what you want, but is less
841 You could declare a name with subtype such as "Foo!Bar". Moose would
842 accept this allowed, but if you used it in a parameterized type such
843 as "ArrayRef[Foo!Bar]" it wouldn't work. We now do some vetting on
844 names created via the sugar functions, so that they can only contain
845 alphanumerics, ":", and ".".
849 Methods created via an attribute can now fulfill a C<requires>
850 declaration for a role. Honestly we don't know why Stevan didn't make
851 this work originally, he was just insane or something.
853 Stack traces from inlined code will now report the line and file as
854 being in your class, as opposed to in Moose guts.
858 When a class does not provide all of a role's required methods, the
859 error thrown now mentions all of the missing methods, as opposed to
860 just the first missing method.
862 Moose will no longer inline a constructor for your class unless it
863 inherits its constructor from Moose::Object, and will warn when it
864 doesn't inline. If you want to force inlining anyway, pass
865 C<< replace_constructor => 1 >> to C<make_immutable>.
867 If you want to get rid of the warning, pass C<< inline_constructor =>
872 Removed the (deprecated) C<make_immutable> keyword.
874 Removing an attribute from a class now also removes delegation
875 (C<handles>) methods installed for that attribute. This is correct
876 behavior, but if you were wrongly relying on it you might get bit.
880 Roles now add methods by calling C<add_method>, not
881 C<alias_method>. They make sure to always provide a method object,
882 which will be cloned internally. This means that it is now possible to
883 track the source of a method provided by a role, and even follow its
884 history through intermediate roles. This means that methods added by
885 a role now show up when looking at a class's method list/map.
887 Parameter and Union args are now sorted, this makes Int|Str the same
888 constraint as Str|Int. Also, incoming type constraint strings are
889 normalized to remove all whitespace differences. This is mostly for
890 internals and should not affect outside code.
892 L<Moose::Exporter> will no longer remove a subroutine that the
893 exporting package re-exports. Moose re-exports the Carp::confess
894 function, among others. The reasoning is that we cannot know whether
895 you have also explicitly imported those functions for your own use, so
896 we err on the safe side and always keep them.
900 C<Moose::init_meta> should now be called as a method.
902 New modules for extension writers, L<Moose::Exporter> and
903 L<Moose::Util::MetaRole>.
907 Implemented metaclass traits (and wrote a recipe for it):
909 use Moose -traits => 'Foo'
911 This should make writing small Moose extensions a little
916 Fixed C<coerce> to accept anon types just like C<subtype> can.
919 coerce $some_anon_type => from 'Str' => via { ... };
923 Added C<BUILDARGS>, a new step in C<< Moose::Object->new() >>.
927 Fixed how the C<< is => (ro|rw) >> works with custom defined
928 C<reader>, C<writer> and C<accessor> options. See the below table for
931 is => ro, writer => _foo # turns into (reader => foo, writer => _foo)
932 is => rw, writer => _foo # turns into (reader => foo, writer => _foo)
933 is => rw, accessor => _foo # turns into (accessor => _foo)
934 is => ro, accessor => _foo # error, accesor is rw
938 The C<before/around/after> method modifiers now support regexp
939 matching of method names. NOTE: this only works for classes, it is
940 currently not supported in roles, but, ... patches welcome.
942 The C<has> keyword for roles now accepts the same array ref form that
943 L<Moose>.pm does for classes.
945 A trigger on a read-only attribute is no longer an error, as it's
946 useful to trigger off of the constructor.
948 Subtypes of parameterizable types now are parameterizable types
953 Fixed issue where C<DEMOLISHALL> was eating the value in C<$@>, and so
954 not working correctly. It still kind of eats them, but so does vanilla
959 Inherited attributes may now be extended without restriction on the
960 type ('isa', 'does').
962 The entire set of Moose::Meta::TypeConstraint::* classes were
963 refactored in this release. If you were relying on their internals you
964 should test your code carefully.
968 Documenting the use of '+name' with attributes that come from recently
969 composed roles. It makes sense, people are using it, and so why not
970 just officially support it.
972 The C<< Moose::Meta::Class->create >> method now supports roles.
974 It is now possible to make anonymous enum types by passing C<enum> an
975 array reference instead of the C<< enum $name => @values >>.
979 Added the C<make_immutable> keyword as a shortcut to calling
980 C<make_immutable> on the meta object. This eventually got removed!
982 Made C<< init_arg => undef >> work in Moose. This means "do not accept
983 a constructor parameter for this attribute".
985 Type errors now use the provided message. Prior to this release they
990 Moose is now a postmodern object system :)
992 The Role system was completely refactored. It is 100% backwards
993 compat, but the internals were totally changed. If you relied on the
994 internals then you are advised to test carefully.
996 Added method exclusion and aliasing for Roles in this release.
998 Added the L<Moose::Util::TypeConstraints::OptimizedConstraints>
1001 Passing a list of values to an accessor (which is only expecting one
1002 value) used to be silently ignored, now it throws an error.
1006 Added parameterized types and did a pretty heavy refactoring of the
1007 type constraint system.
1009 Better framework extensibility and better support for "making your own
1012 =head1 0.25 or before
1014 Honestly, you shouldn't be using versions of Moose that are this old,
1015 so many bug fixes and speed improvements have been made you would be
1016 crazy to not upgrade.
1018 Also, I am tired of going through the Changelog so I am stopping here,
1019 if anyone would like to continue this please feel free.