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 Union types consider all members in the C<is_subtype_of> and C<is_a_type_of> methods
28 Previously, a union type would report itself as being of a subtype of a type
29 if I<any> of its member types were subtypes of that type. This has changed
30 so that I<all> of its member types must be a subtype of the specified type.
32 =item Hand-optimized type constraint code causes a deprecation warning
34 If you provide an optimized sub ref for a type constraint, this now causes a
35 deprecation warning. Typically, this comes from passing an C<optimize_as>
36 parameter to C<subtype>, but it could also happen if you create a
37 L<Moose::Meta::TypeConstraint> object directly.
39 Use the inlining feature (C<inline_as>) added in 2.0100 instead.
47 =item Array and Hash native traits provide a C<shallow_clone> method
49 The Array and Hash native traits now provide a "shallow_clone" method, which
50 will return a reference to a new container with the same contents as the
51 attribute's reference.
59 =item Hand-optimized type constraint code is deprecated in favor of inlining
61 Moose allows you to provide a hand-optimized version of a type constraint's
62 subroutine reference. This version allows type constraints to generate inline
63 code, and you should use this inlining instead of providing a hand-optimized
66 This affects the C<optimize_as> sub exported by
67 L<Moose::Util::TypeConstraints>. Use C<inline_as> instead.
69 This will start warning in the 2.0300 release.
77 =item More useful type constraint error messages
79 If you have L<Devel::PartialDump> version 0.14 or higher installed, Moose's
80 type constraint error messages will use it to display the invalid value, rather
81 than just displaying it directly. This will generally be much more useful. For
82 instance, instead of this:
84 Attribute (foo) does not pass the type constraint because: Validation failed for 'ArrayRef[Int]' with value ARRAY(0x275eed8)
86 the error message will instead look like
88 Attribute (foo) does not pass the type constraint because: Validation failed for 'ArrayRef[Int]' with value [ "a" ]
90 Note that L<Devel::PartialDump> can't be made a direct dependency at the
91 moment, because it uses Moose itself, but we're considering options to make
100 =item Roles have their own default attribute metaclass
102 Previously, when a role was applied to a class, it would use the attribute
103 metaclass defined in the class when copying over the attributes in the role.
104 This was wrong, because for instance, using L<MooseX::FollowPBP> in the class
105 would end up renaming all of the accessors generated by the role, some of which
106 may be being called in the role, causing it to break. Roles now keep track of
107 their own attribute metaclass to use by default when being applied to a class
108 (defaulting to Moose::Meta::Attribute). This is modifiable using
109 L<Moose::Util::MetaRole> by passing the C<applied_attribute> key to the
110 C<role_metaroles> option, as in:
112 Moose::Util::MetaRole::apply_metaroles(
115 attribute => ['My::Meta::Role::Attribute'],
118 applied_attribute => ['My::Meta::Role::Attribute'],
122 =item Class::MOP has been folded into the Moose dist
124 Moose and Class::MOP are tightly related enough that they have always had to be
125 kept pretty closely in step in terms of versions. Making them into a single
126 dist should simplify the upgrade process for users, as it should no longer be
127 possible to upgrade one without the other and potentially cause issues. No
128 functionality has changed, and this should be entirely transparent.
130 =item Moose's conflict checking is more robust and useful
132 There are two parts to this. The most useful one right now is that Moose will
133 ship with a C<moose-outdated> script, which can be run at any point to list the
134 modules which are installed that conflict with the installed version of Moose.
135 After upgrading Moose, running C<moose-outdated | cpanm> should be sufficient
136 to ensure that all of the Moose extensions you use will continue to work.
138 The other part is that Moose's C<META.json> file will also specify the
139 conflicts under the C<x_conflicts> key. We are working with the Perl tool chain
140 developers to try to get conflicts support added to CPAN clients, and if/when
141 that happens, the metadata already exists, and so the conflict checking will
144 =item Most deprecated APIs/features are slated for removal in Moose 2.0200
146 Most of the deprecated APIs and features in Moose will start throwing an error
147 in Moose 2.0200. Some of the features will go away entirely, and some will
148 simply throw an error.
150 The things on the chopping block are:
154 =item * Old public methods in Class::MOP and Moose
156 This includes things like C<< Class::MOP::Class->get_attribute_map >>, C<<
157 Class::MOP::Class->construct_instance >>, and many others. These were
158 deprecated in L<Class::MOP> 0.80_01, released on April 5, 2009.
160 These methods will be removed entirely in Moose 2.0200.
162 =item * Old public functions in Class::MOP
164 This include C<Class::MOP::subname>, C<Class::MOP::in_global_destruction>, and
165 the C<Class::MOP::HAS_ISAREV> constant. The first two were deprecated in 0.84,
166 and the last in 0.80. Class::MOP 0.84 was released on May 12, 2009.
168 These functions will be removed entirely in Moose 2.0200.
170 =item * The C<alias> and C<excludes> option for role composition
172 These were renamed to C<-alias> and C<-excludes> in Moose 0.89, released on
175 Passing these will throw an error in Moose 2.0200.
177 =item * The old L<Moose::Util::MetaRole> API
179 This include the C<apply_metaclass_roles()> function, as well as passing the
180 C<for_class> or any key ending in C<_roles> to C<apply_metaroles()>. This was
181 deprecated in Moose 0.93_01, released on January 4, 2010.
183 These will all throw an error in Moose 2.0200.
185 =item * Passing plain lists to C<type()> or C<subtype()>
187 The old API for these functions allowed you to pass a plain list of parameter,
188 rather than a list of hash references (which is what C<as()>, C<where>,
189 etc. return). This was deprecated in Moose 0.71_01, released on February 22,
192 This will throw an error in Moose 2.0200.
194 =item * The Role subtype
196 This subtype was deprecated in Moose 0.84, released on June 26, 2009.
198 This will be removed entirely in Moose 2.0200.
208 =item * New release policy
210 As of the 2.0 release, Moose now has an official release and support policy,
211 documented in L<Moose::Manual::Support>. All API changes will now go through a
212 deprecation cycle of at least one year, after which the deprecated API can be
213 removed. Deprecations and removals will only happen in major releases.
215 In between major releases, we will still make minor releases to add new
216 features, fix bugs, update documentation, etc.
224 =item Configurable stacktraces
226 Classes which use the L<Moose::Error::Default> error class can now have
227 stacktraces disabled by setting the C<MOOSE_ERROR_STYLE> env var to C<croak>.
228 This is experimental, fairly incomplete, and won't work in all cases (because
229 Moose's error system in general is all of these things), but this should allow
230 for reducing at least some of the verbosity in most cases.
238 =item Native Delegations
240 In previous versions of Moose, the Native delegations were created as
241 closures. The generated code was often quite slow compared to doing the same
242 thing by hand. For example, the Array's push delegation ended up doing
245 push @{ $self->$reader() }, @_;
247 If the attribute was created without a reader, the C<$reader> sub reference
248 followed a very slow code path. Even with a reader, this is still slower than
251 Native delegations are now generated as inline code, just like other
252 accessors, so we can access the slot directly.
254 In addition, native traits now do proper constraint checking in all cases. In
255 particular, constraint checking has been improved for array and hash
256 references. Previously, only the I<contained> type (the C<Str> in
257 C<HashRef[Str]>) would be checked when a new value was added to the
258 collection. However, if there was a constraint that applied to the whole
259 value, this was never checked.
261 In addition, coercions are now called on the whole value.
263 The delegation methods now do more argument checking. All of the methods check
264 that a valid number of arguments were passed to the method. In addition, the
265 delegation methods check that the arguments are sane (array indexes, hash
266 keys, numbers, etc.) when applicable. We have tried to emulate the behavior of
267 Perl builtins as much as possible.
269 Finally, triggers are called whenever the value of the attribute is changed by
272 These changes are only likely to break code in a few cases.
274 The inlining code may or may not preserve the original reference when changes
275 are made. In some cases, methods which change the value may replace it
276 entirely. This will break tied values.
278 If you have a typed arrayref or hashref attribute where the type enforces a
279 constraint on the whole collection, this constraint will now be checked. It's
280 possible that code which previously ran without errors will now cause the
281 constraint to fail. However, presumably this is a good thing ;)
283 If you are passing invalid arguments to a delegation which were previously
284 being ignored, these calls will now fail.
286 If your code relied on the trigger only being called for a regular writer,
287 that may cause problems.
289 As always, you are encouraged to test before deploying the latest version of
292 =item Defaults is and default for String, Counter, and Bool
294 A few native traits (String, Counter, Bool) provide default values of "is" and
295 "default" when you created an attribute. Allowing them to provide these values
296 is now deprecated. Supply the value yourself when creating the attribute.
298 =item The C<meta> method
300 Moose and Class::MOP have been cleaned up internally enough to make the
301 C<meta> method that you get by default optional. C<use Moose> and
302 C<use Moose::Role> now can take an additional C<-meta_name> option, which
303 tells Moose what name to use when installing the C<meta> method. Passing
304 C<undef> to this option suppresses generation of the C<meta> method
305 entirely. This should be useful for users of modules which also use a C<meta>
306 method or function, such as L<Curses> or L<Rose::DB::Object>.
314 =item All deprecated features now warn
316 Previously, deprecation mostly consisted of simply saying "X is deprecated" in
317 the Changes file. We were not very consistent about actually warning. Now, all
318 deprecated features still present in Moose actually give a warning. The
319 warning is issued once per calling package. See L<Moose::Deprecated> for more
322 =item You cannot pass C<< coerce => 1 >> unless the attribute's type constraint has a coercion
324 Previously, this was accepted, and it sort of worked, except that if you
325 attempted to set the attribute after the object was created, you would get a
328 Now you will get a warning when you attempt to define the attribute.
330 =item C<no Moose>, C<no Moose::Role>, and C<no Moose::Exporter> no longer unimport strict and warnings
332 This change was made in 1.05, and has now been reverted. We don't know if the
333 user has explicitly loaded strict or warnings on their own, and unimporting
334 them is just broken in that case.
336 =item Reversed logic when defining which options can be changed
338 L<Moose::Meta::Attribute> now allows all options to be changed in an
339 overridden attribute. The previous behaviour required each option to be
340 whitelisted using the C<legal_options_for_inheritance> method. This method has
341 been removed, and there is a new method, C<illegal_options_for_inheritance>,
342 which can now be used to prevent certain options from being changeable.
344 In addition, we only throw an error if the illegal option is actually
345 changed. If the superclass didn't specify this option at all when defining the
346 attribute, the subclass version can still add it as an option.
348 Example of overriding this in an attribute trait:
350 package Bar::Meta::Attribute;
353 has 'my_illegal_option' => (
358 around illegal_options_for_inheritance => sub {
359 return ( shift->(@_), qw/my_illegal_option/ );
368 =item L<Moose::Object/BUILD> methods are now called when calling C<new_object>
370 Previously, C<BUILD> methods would only be called from C<Moose::Object::new>,
371 but now they are also called when constructing an object via
372 C<Moose::Meta::Class::new_object>. C<BUILD> methods are an inherent part of the
373 object construction process, and this should make C<< $meta->new_object >>
374 actually usable without forcing people to use C<< $meta->name->new >>.
376 =item C<no Moose>, C<no Moose::Role>, and C<no Moose::Exporter> now unimport strict and warnings
378 In the interest of having C<no Moose> clean up everything that C<use Moose>
379 does in the calling scope, C<no Moose> (as well as all other
380 L<Moose::Exporter>-using modules) now unimports strict and warnings.
382 =item Metaclass compatibility checking and fixing should be much more robust
384 The L<metaclass compatibility|Moose/METACLASS COMPATIBILITY AND MOOSE> checking
385 and fixing algorithms have been completely rewritten, in both Class::MOP and
386 Moose. This should resolve many confusing errors when dealing with non-Moose
387 inheritance and with custom metaclasses for things like attributes,
388 constructors, etc. For correct code, the only thing that should require a
389 change is that custom error metaclasses must now inherit from
390 L<Moose::Error::Default>.
398 =item Moose::Meta::TypeConstraint::Class is_subtype_of behavior
400 Earlier versions of L<is_subtype_of|Moose::Meta::TypeConstraint::Class/is_subtype_of>
401 would incorrectly return true when called with itself, its own TC name or
402 its class name as an argument. (i.e. $foo_tc->is_subtype_of('Foo') == 1) This
403 behavior was a caused by C<isa> being checked before the class name. The old
404 behavior can be accessed with L<is_type_of|Moose::Meta::TypeConstraint::Class/is_type_of>
412 =item Moose::Meta::Attribute::Native::Trait::Code no longer creates reader methods by default
414 Earlier versions of L<Moose::Meta::Attribute::Native::Trait::Code> created
415 read-only accessors for the attributes it's been applied to, even if you didn't
416 ask for it with C<< is => 'ro' >>. This incorrect behaviour has now been fixed.
424 =item Moose::Util add_method_modifier behavior
426 add_method_modifier (and subsequently the sugar functions Moose::before,
427 Moose::after, and Moose::around) can now accept arrayrefs, with the same
428 behavior as lists. Types other than arrayref and regexp result in an error.
432 =head1 0.93_01 and 0.94
436 =item Moose::Util::MetaRole API has changed
438 The C<apply_metaclass_roles> function is now called C<apply_metaroles>. The
439 way arguments are supplied has been changed to force you to distinguish
440 between metaroles applied to L<Moose::Meta::Class> (and helpers) versus
441 L<Moose::Meta::Role>.
443 The old API still works, but will warn in a future release, and eventually be
446 =item Moose::Meta::Role has real attributes
448 The attributes returned by L<Moose::Meta::Role> are now instances of the
449 L<Moose::Meta::Role::Attribute> class, instead of bare hash references.
451 =item "no Moose" now removes C<blessed> and C<confess>
453 Moose is now smart enough to know exactly what it exported, even when it
454 re-exports functions from other packages. When you unimport Moose, it will
455 remove these functions from your namespace unless you I<also> imported them
456 directly from their respective packages.
458 If you have a C<no Moose> in your code I<before> you call C<blessed> or
459 C<confess>, your code will break. You can either move the C<no Moose> call
460 later in your code, or explicitly import the relevant functions from the
461 packages that provide them.
463 =item L<Moose::Exporter> is smarter about unimporting re-exports
465 The change above comes from a general improvement to L<Moose::Exporter>. It
466 will now unimport any function it exports, even if that function is a
467 re-export from another package.
469 =item Attributes in roles can no longer override class attributes with "+foo"
471 Previously, this worked more or less accidentally, because role attributes
472 weren't objects. This was never documented, but a few MooseX modules took
475 =item The composition_class_roles attribute in L<Moose::Meta::Role> is now a method
477 This was done to make it possible for roles to alter the the list of
478 composition class roles by applying a method modifiers. Previously, this was
479 an attribute and MooseX modules override it. Since that no longer works, this
482 This I<should> be an attribute, so this may switch back to being an attribute
483 in the future if we can figure out how to make this work.
491 =item Calling $object->new() is no longer deprecated
493 We decided to undeprecate this. Now it just works.
495 =item Both C<get_method_map> and C<get_attribute_map> is deprecated
497 These metaclass methods were never meant to be public, and they are both now
498 deprecated. The work around if you still need the functionality they provided
499 is to iterate over the list of names manually.
501 my %fields = map { $_ => $meta->get_attribute($_) } $meta->get_attribute_list;
503 This was actually a change in L<Class::MOP>, but this version of Moose
504 requires a version of L<Class::MOP> that includes said change.
512 =item Added Native delegation for Code refs
514 See L<Moose::Meta::Attribute::Native::Trait::Code> for details.
516 =item Calling $object->new() is deprecated
518 Moose has long supported this, but it's never really been documented, and we
519 don't think this is a good practice. If you want to construct an object from
520 an existing object, you should provide some sort of alternate constructor like
521 C<< $object->clone >>.
523 Calling C<< $object->new >> now issues a warning, and will be an error in a
526 =item Moose no longer warns if you call C<make_immutable> for a class with mutable ancestors
528 While in theory this is a good thing to warn about, we found so many
529 exceptions to this that doing this properly became quite problematic.
537 =item New Native delegation methods from L<List::Util> and L<List::MoreUtils>
539 In particular, we now have C<reduce>, C<shuffle>, C<uniq>, and C<natatime>.
541 =item The Moose::Exporter with_caller feature is now deprecated
543 Use C<with_meta> instead. The C<with_caller> option will start warning in a
546 =item Moose now warns if you call C<make_immutable> for a class with mutable ancestors
548 This is dangerous because modifying a class after a subclass has been
549 immutabilized will lead to incorrect results in the subclass, due to inlining,
550 caching, etc. This occasionally happens accidentally, when a class loads one
551 of its subclasses in the middle of its class definition, so pointing out that
552 this may cause issues should be helpful. Metaclasses (classes that inherit
553 from L<Class::MOP::Object>) are currently exempt from this check, since at the
554 moment we aren't very consistent about which metaclasses we immutabilize.
556 =item C<enum> and C<duck_type> now take arrayrefs for all forms
558 Previously, calling these functions with a list would take the first element of
559 the list as the type constraint name, and use the remainder as the enum values
560 or method names. This makes the interface inconsistent with the anon-type forms
561 of these functions (which must take an arrayref), and a free-form list where
562 the first value is sometimes special is hard to validate (and harder to give
563 reasonable error messages for). These functions have been changed to take
564 arrayrefs in all their forms - so, C<< enum 'My::Type' => [qw(foo bar)] >> is
565 now the preferred way to create an enum type constraint. The old syntax still
566 works for now, but it will hopefully be deprecated and removed in a future
573 L<Moose::Meta::Attribute::Native> has been moved into the Moose core from
574 L<MooseX::AttributeHelpers>. Major changes include:
578 =item C<traits>, not C<metaclass>
580 Method providers are only available via traits.
582 =item C<handles>, not C<provides> or C<curries>
584 The C<provides> syntax was like core Moose C<< handles => HASHREF >>
585 syntax, but with the keys and values reversed. This was confusing,
586 and AttributeHelpers now uses C<< handles => HASHREF >> in a way that
587 should be intuitive to anyone already familiar with how it is used for
590 The C<curries> functionality provided by AttributeHelpers has been
591 generalized to apply to all cases of C<< handles => HASHREF >>, though
592 not every piece of functionality has been ported (currying with a
593 CODEREF is not supported).
595 =item C<empty> is now C<is_empty>, and means empty, not non-empty
597 Previously, the C<empty> method provided by Arrays and Hashes returned true if
598 the attribute was B<not> empty (no elements). Now it returns true if the
599 attribute B<is> empty. It was also renamed to C<is_empty>, to reflect this.
601 =item C<find> was renamed to C<first>, and C<first> and C<last> were removed
603 L<List::Util> refers to the functionality that we used to provide under C<find>
604 as L<first|List::Util/first>, so that will likely be more familiar (and will
605 fit in better if we decide to add more List::Util functions). C<first> and
606 C<last> were removed, since their functionality is easily duplicated with
609 =item Helpers that take a coderef of one argument now use C<$_>
611 Subroutines passed as the first argument to C<first>, C<map>, and C<grep> now
612 receive their argument in C<$_> rather than as a parameter to the subroutine.
613 Helpers that take a coderef of two or more arguments remain using the argument
614 list (there are technical limitations to using C<$a> and C<$b> like C<sort>
617 See L<Moose::Meta::Attribute::Native> for the new documentation.
621 The C<alias> and C<excludes> role parameters have been renamed to C<-alias>
622 and C<-excludes>. The old names still work, but new code should use the new
623 names, and eventually the old ones will be deprecated and removed.
627 C<< use Moose -metaclass => 'Foo' >> now does alias resolution, just like
628 C<-traits> (and the C<metaclass> and C<traits> options to C<has>).
630 Added two functions C<meta_class_alias> and C<meta_attribute_alias> to
631 L<Moose::Util>, to simplify aliasing metaclasses and metatraits. This is
632 a wrapper around the old
634 package Moose::Meta::Class::Custom::Trait::FooTrait;
635 sub register_implementation { 'My::Meta::Trait' }
641 When an attribute generates I<no> accessors, we now warn. This is to help
642 users who forget the C<is> option. If you really do not want any accessors,
643 you can use C<< is => 'bare' >>. You can maintain back compat with older
644 versions of Moose by using something like:
646 ($Moose::VERSION >= 0.84 ? is => 'bare' : ())
648 When an accessor overwrites an existing method, we now warn. To work around
649 this warning (if you really must have this behavior), you can explicitly
650 remove the method before creating it as an accessor:
654 __PACKAGE__->meta->remove_method('foo');
660 When an unknown option is passed to C<has>, we now warn. You can silence
661 the warning by fixing your code. :)
663 The C<Role> type has been deprecated. On its own, it was useless,
664 since it just checked C<< $object->can('does') >>. If you were using
665 it as a parent type, just call C<role_type('Role::Name')> to create an
666 appropriate type instead.
670 C<use Moose::Exporter;> now imports C<strict> and C<warnings> into packages
675 C<DEMOLISHALL> and C<DEMOLISH> now receive an argument indicating whether or
676 not we are in global destruction.
680 Type constraints no longer run coercions for a value that already matches the
681 constraint. This may affect some (arguably buggy) edge case coercions that
682 rely on side effects in the C<via> clause.
686 L<Moose::Exporter> now accepts the C<-metaclass> option for easily
687 overriding the metaclass (without L<metaclass>). This works for classes
692 Added a C<duck_type> sugar function to L<Moose::Util::TypeConstraints>
693 to make integration with non-Moose classes easier. It simply checks if
694 C<< $obj->can() >> a list of methods.
696 A number of methods (mostly inherited from L<Class::MOP>) have been
697 renamed with a leading underscore to indicate their internal-ness. The
698 old method names will still work for a while, but will warn that the
699 method has been renamed. In a few cases, the method will be removed
700 entirely in the future. This may affect MooseX authors who were using
705 Calling C<subtype> with a name as the only argument now throws an
706 exception. If you want an anonymous subtype do:
708 my $subtype = subtype as 'Foo';
710 This is related to the changes in version 0.71_01.
712 The C<is_needed> method in L<Moose::Meta::Method::Destructor> is now
713 only usable as a class method. Previously, it worked as a class or
714 object method, with a different internal implementation for each
717 The internals of making a class immutable changed a lot in Class::MOP
718 0.78_02, and Moose's internals have changed along with it. The
719 external C<< $metaclass->make_immutable >> method still works the same
724 A mutable class accepted C<< Foo->new(undef) >> without complaint,
725 while an immutable class would blow up with an unhelpful error. Now,
726 in both cases we throw a helpful error instead.
728 This "feature" was originally added to allow for cases such as this:
736 return My::Class->new($args);
738 But we decided this is a bad idea and a little too magical, because it
739 can easily mask real errors.
743 Calling C<type> or C<subtype> without the sugar helpers (C<as>,
744 C<where>, C<message>) is now deprecated.
746 As a side effect, this meant we ended up using Perl prototypes on
747 C<as>, and code like this will no longer work:
749 use Moose::Util::TypeConstraints;
750 use Declare::Constraints::Simple -All;
752 subtype 'ArrayOfInts'
754 => IsArrayRef(IsInt);
756 Instead it must be changed to this:
761 where => IsArrayRef(IsInt)
765 If you want to maintain backwards compat with older versions of Moose,
766 you must explicitly test Moose's C<VERSION>:
768 if ( Moose->VERSION < 0.71_01 ) {
769 subtype 'ArrayOfInts'
771 => IsArrayRef(IsInt);
777 where => IsArrayRef(IsInt)
784 We no longer pass the meta-attribute object as a final argument to
785 triggers. This actually changed for inlined code a while back, but the
786 non-inlined version and the docs were still out of date.
788 If by some chance you actually used this feature, the workaround is
789 simple. You fetch the attribute object from out of the C<$self>
790 that is passed as the first argument to trigger, like so:
796 my ( $self, $value ) = @_;
797 my $attr = $self->meta->find_attribute_by_name('foo');
805 If you created a subtype and passed a parent that Moose didn't know
806 about, it simply ignored the parent. Now it automatically creates the
807 parent as a class type. This may not be what you want, but is less
810 You could declare a name with subtype such as "Foo!Bar". Moose would
811 accept this allowed, but if you used it in a parameterized type such
812 as "ArrayRef[Foo!Bar]" it wouldn't work. We now do some vetting on
813 names created via the sugar functions, so that they can only contain
814 alphanumerics, ":", and ".".
818 Methods created via an attribute can now fulfill a C<requires>
819 declaration for a role. Honestly we don't know why Stevan didn't make
820 this work originally, he was just insane or something.
822 Stack traces from inlined code will now report the line and file as
823 being in your class, as opposed to in Moose guts.
827 When a class does not provide all of a role's required methods, the
828 error thrown now mentions all of the missing methods, as opposed to
829 just the first missing method.
831 Moose will no longer inline a constructor for your class unless it
832 inherits its constructor from Moose::Object, and will warn when it
833 doesn't inline. If you want to force inlining anyway, pass
834 C<< replace_constructor => 1 >> to C<make_immutable>.
836 If you want to get rid of the warning, pass C<< inline_constructor =>
841 Removed the (deprecated) C<make_immutable> keyword.
843 Removing an attribute from a class now also removes delegation
844 (C<handles>) methods installed for that attribute. This is correct
845 behavior, but if you were wrongly relying on it you might get bit.
849 Roles now add methods by calling C<add_method>, not
850 C<alias_method>. They make sure to always provide a method object,
851 which will be cloned internally. This means that it is now possible to
852 track the source of a method provided by a role, and even follow its
853 history through intermediate roles. This means that methods added by
854 a role now show up when looking at a class's method list/map.
856 Parameter and Union args are now sorted, this makes Int|Str the same
857 constraint as Str|Int. Also, incoming type constraint strings are
858 normalized to remove all whitespace differences. This is mostly for
859 internals and should not affect outside code.
861 L<Moose::Exporter> will no longer remove a subroutine that the
862 exporting package re-exports. Moose re-exports the Carp::confess
863 function, among others. The reasoning is that we cannot know whether
864 you have also explicitly imported those functions for your own use, so
865 we err on the safe side and always keep them.
869 C<Moose::init_meta> should now be called as a method.
871 New modules for extension writers, L<Moose::Exporter> and
872 L<Moose::Util::MetaRole>.
876 Implemented metaclass traits (and wrote a recipe for it):
878 use Moose -traits => 'Foo'
880 This should make writing small Moose extensions a little
885 Fixed C<coerce> to accept anon types just like C<subtype> can.
888 coerce $some_anon_type => from 'Str' => via { ... };
892 Added C<BUILDARGS>, a new step in C<< Moose::Object->new() >>.
896 Fixed how the C<< is => (ro|rw) >> works with custom defined
897 C<reader>, C<writer> and C<accessor> options. See the below table for
900 is => ro, writer => _foo # turns into (reader => foo, writer => _foo)
901 is => rw, writer => _foo # turns into (reader => foo, writer => _foo)
902 is => rw, accessor => _foo # turns into (accessor => _foo)
903 is => ro, accessor => _foo # error, accesor is rw
907 The C<before/around/after> method modifiers now support regexp
908 matching of method names. NOTE: this only works for classes, it is
909 currently not supported in roles, but, ... patches welcome.
911 The C<has> keyword for roles now accepts the same array ref form that
912 L<Moose>.pm does for classes.
914 A trigger on a read-only attribute is no longer an error, as it's
915 useful to trigger off of the constructor.
917 Subtypes of parameterizable types now are parameterizable types
922 Fixed issue where C<DEMOLISHALL> was eating the value in C<$@>, and so
923 not working correctly. It still kind of eats them, but so does vanilla
928 Inherited attributes may now be extended without restriction on the
929 type ('isa', 'does').
931 The entire set of Moose::Meta::TypeConstraint::* classes were
932 refactored in this release. If you were relying on their internals you
933 should test your code carefully.
937 Documenting the use of '+name' with attributes that come from recently
938 composed roles. It makes sense, people are using it, and so why not
939 just officially support it.
941 The C<< Moose::Meta::Class->create >> method now supports roles.
943 It is now possible to make anonymous enum types by passing C<enum> an
944 array reference instead of the C<< enum $name => @values >>.
948 Added the C<make_immutable> keyword as a shortcut to calling
949 C<make_immutable> on the meta object. This eventually got removed!
951 Made C<< init_arg => undef >> work in Moose. This means "do not accept
952 a constructor parameter for this attribute".
954 Type errors now use the provided message. Prior to this release they
959 Moose is now a postmodern object system :)
961 The Role system was completely refactored. It is 100% backwards
962 compat, but the internals were totally changed. If you relied on the
963 internals then you are advised to test carefully.
965 Added method exclusion and aliasing for Roles in this release.
967 Added the L<Moose::Util::TypeConstraints::OptimizedConstraints>
970 Passing a list of values to an accessor (which is only expecting one
971 value) used to be silently ignored, now it throws an error.
975 Added parameterized types and did a pretty heavy refactoring of the
976 type constraint system.
978 Better framework extensibility and better support for "making your own
981 =head1 0.25 or before
983 Honestly, you shouldn't be using versions of Moose that are this old,
984 so many bug fixes and speed improvements have been made you would be
985 crazy to not upgrade.
987 Also, I am tired of going through the Changelog so I am stopping here,
988 if anyone would like to continue this please feel free.