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 has been changed to find the nearest common ancestor for all of
30 its components. For example, a union of "Int|ArrayRef[Int]" now has a parent
33 =item Union types consider all members in the C<is_subtype_of> and C<is_a_type_of> methods
35 Previously, a union type would report itself as being of a subtype of a type
36 if I<any> of its member types were subtypes of that type. This has changed
37 so that I<all> of its member types must be a subtype of the specified type.
39 =item Hand-optimized type constraint code causes a deprecation warning
41 If you provide an optimized sub ref for a type constraint, this now causes a
42 deprecation warning. Typically, this comes from passing an C<optimize_as>
43 parameter to C<subtype>, but it could also happen if you create a
44 L<Moose::Meta::TypeConstraint> object directly.
46 Use the inlining feature (C<inline_as>) added in 2.0100 instead.
54 =item Array and Hash native traits provide a C<shallow_clone> method
56 The Array and Hash native traits now provide a "shallow_clone" method, which
57 will return a reference to a new container with the same contents as the
58 attribute's reference.
66 =item Hand-optimized type constraint code is deprecated in favor of inlining
68 Moose allows you to provide a hand-optimized version of a type constraint's
69 subroutine reference. This version allows type constraints to generate inline
70 code, and you should use this inlining instead of providing a hand-optimized
73 This affects the C<optimize_as> sub exported by
74 L<Moose::Util::TypeConstraints>. Use C<inline_as> instead.
76 This will start warning in the 2.0300 release.
84 =item More useful type constraint error messages
86 If you have L<Devel::PartialDump> version 0.14 or higher installed, Moose's
87 type constraint error messages will use it to display the invalid value, rather
88 than just displaying it directly. This will generally be much more useful. For
89 instance, instead of this:
91 Attribute (foo) does not pass the type constraint because: Validation failed for 'ArrayRef[Int]' with value ARRAY(0x275eed8)
93 the error message will instead look like
95 Attribute (foo) does not pass the type constraint because: Validation failed for 'ArrayRef[Int]' with value [ "a" ]
97 Note that L<Devel::PartialDump> can't be made a direct dependency at the
98 moment, because it uses Moose itself, but we're considering options to make
107 =item Roles have their own default attribute metaclass
109 Previously, when a role was applied to a class, it would use the attribute
110 metaclass defined in the class when copying over the attributes in the role.
111 This was wrong, because for instance, using L<MooseX::FollowPBP> in the class
112 would end up renaming all of the accessors generated by the role, some of which
113 may be being called in the role, causing it to break. Roles now keep track of
114 their own attribute metaclass to use by default when being applied to a class
115 (defaulting to Moose::Meta::Attribute). This is modifiable using
116 L<Moose::Util::MetaRole> by passing the C<applied_attribute> key to the
117 C<role_metaroles> option, as in:
119 Moose::Util::MetaRole::apply_metaroles(
122 attribute => ['My::Meta::Role::Attribute'],
125 applied_attribute => ['My::Meta::Role::Attribute'],
129 =item Class::MOP has been folded into the Moose dist
131 Moose and Class::MOP are tightly related enough that they have always had to be
132 kept pretty closely in step in terms of versions. Making them into a single
133 dist should simplify the upgrade process for users, as it should no longer be
134 possible to upgrade one without the other and potentially cause issues. No
135 functionality has changed, and this should be entirely transparent.
137 =item Moose's conflict checking is more robust and useful
139 There are two parts to this. The most useful one right now is that Moose will
140 ship with a C<moose-outdated> script, which can be run at any point to list the
141 modules which are installed that conflict with the installed version of Moose.
142 After upgrading Moose, running C<moose-outdated | cpanm> should be sufficient
143 to ensure that all of the Moose extensions you use will continue to work.
145 The other part is that Moose's C<META.json> file will also specify the
146 conflicts under the C<x_conflicts> key. We are working with the Perl tool chain
147 developers to try to get conflicts support added to CPAN clients, and if/when
148 that happens, the metadata already exists, and so the conflict checking will
151 =item Most deprecated APIs/features are slated for removal in Moose 2.0200
153 Most of the deprecated APIs and features in Moose will start throwing an error
154 in Moose 2.0200. Some of the features will go away entirely, and some will
155 simply throw an error.
157 The things on the chopping block are:
161 =item * Old public methods in Class::MOP and Moose
163 This includes things like C<< Class::MOP::Class->get_attribute_map >>, C<<
164 Class::MOP::Class->construct_instance >>, and many others. These were
165 deprecated in L<Class::MOP> 0.80_01, released on April 5, 2009.
167 These methods will be removed entirely in Moose 2.0200.
169 =item * Old public functions in Class::MOP
171 This include C<Class::MOP::subname>, C<Class::MOP::in_global_destruction>, and
172 the C<Class::MOP::HAS_ISAREV> constant. The first two were deprecated in 0.84,
173 and the last in 0.80. Class::MOP 0.84 was released on May 12, 2009.
175 These functions will be removed entirely in Moose 2.0200.
177 =item * The C<alias> and C<excludes> option for role composition
179 These were renamed to C<-alias> and C<-excludes> in Moose 0.89, released on
182 Passing these will throw an error in Moose 2.0200.
184 =item * The old L<Moose::Util::MetaRole> API
186 This include the C<apply_metaclass_roles()> function, as well as passing the
187 C<for_class> or any key ending in C<_roles> to C<apply_metaroles()>. This was
188 deprecated in Moose 0.93_01, released on January 4, 2010.
190 These will all throw an error in Moose 2.0200.
192 =item * Passing plain lists to C<type()> or C<subtype()>
194 The old API for these functions allowed you to pass a plain list of parameter,
195 rather than a list of hash references (which is what C<as()>, C<where>,
196 etc. return). This was deprecated in Moose 0.71_01, released on February 22,
199 This will throw an error in Moose 2.0200.
201 =item * The Role subtype
203 This subtype was deprecated in Moose 0.84, released on June 26, 2009.
205 This will be removed entirely in Moose 2.0200.
215 =item * New release policy
217 As of the 2.0 release, Moose now has an official release and support policy,
218 documented in L<Moose::Manual::Support>. All API changes will now go through a
219 deprecation cycle of at least one year, after which the deprecated API can be
220 removed. Deprecations and removals will only happen in major releases.
222 In between major releases, we will still make minor releases to add new
223 features, fix bugs, update documentation, etc.
231 =item Configurable stacktraces
233 Classes which use the L<Moose::Error::Default> error class can now have
234 stacktraces disabled by setting the C<MOOSE_ERROR_STYLE> env var to C<croak>.
235 This is experimental, fairly incomplete, and won't work in all cases (because
236 Moose's error system in general is all of these things), but this should allow
237 for reducing at least some of the verbosity in most cases.
245 =item Native Delegations
247 In previous versions of Moose, the Native delegations were created as
248 closures. The generated code was often quite slow compared to doing the same
249 thing by hand. For example, the Array's push delegation ended up doing
252 push @{ $self->$reader() }, @_;
254 If the attribute was created without a reader, the C<$reader> sub reference
255 followed a very slow code path. Even with a reader, this is still slower than
258 Native delegations are now generated as inline code, just like other
259 accessors, so we can access the slot directly.
261 In addition, native traits now do proper constraint checking in all cases. In
262 particular, constraint checking has been improved for array and hash
263 references. Previously, only the I<contained> type (the C<Str> in
264 C<HashRef[Str]>) would be checked when a new value was added to the
265 collection. However, if there was a constraint that applied to the whole
266 value, this was never checked.
268 In addition, coercions are now called on the whole value.
270 The delegation methods now do more argument checking. All of the methods check
271 that a valid number of arguments were passed to the method. In addition, the
272 delegation methods check that the arguments are sane (array indexes, hash
273 keys, numbers, etc.) when applicable. We have tried to emulate the behavior of
274 Perl builtins as much as possible.
276 Finally, triggers are called whenever the value of the attribute is changed by
279 These changes are only likely to break code in a few cases.
281 The inlining code may or may not preserve the original reference when changes
282 are made. In some cases, methods which change the value may replace it
283 entirely. This will break tied values.
285 If you have a typed arrayref or hashref attribute where the type enforces a
286 constraint on the whole collection, this constraint will now be checked. It's
287 possible that code which previously ran without errors will now cause the
288 constraint to fail. However, presumably this is a good thing ;)
290 If you are passing invalid arguments to a delegation which were previously
291 being ignored, these calls will now fail.
293 If your code relied on the trigger only being called for a regular writer,
294 that may cause problems.
296 As always, you are encouraged to test before deploying the latest version of
299 =item Defaults is and default for String, Counter, and Bool
301 A few native traits (String, Counter, Bool) provide default values of "is" and
302 "default" when you created an attribute. Allowing them to provide these values
303 is now deprecated. Supply the value yourself when creating the attribute.
305 =item The C<meta> method
307 Moose and Class::MOP have been cleaned up internally enough to make the
308 C<meta> method that you get by default optional. C<use Moose> and
309 C<use Moose::Role> now can take an additional C<-meta_name> option, which
310 tells Moose what name to use when installing the C<meta> method. Passing
311 C<undef> to this option suppresses generation of the C<meta> method
312 entirely. This should be useful for users of modules which also use a C<meta>
313 method or function, such as L<Curses> or L<Rose::DB::Object>.
321 =item All deprecated features now warn
323 Previously, deprecation mostly consisted of simply saying "X is deprecated" in
324 the Changes file. We were not very consistent about actually warning. Now, all
325 deprecated features still present in Moose actually give a warning. The
326 warning is issued once per calling package. See L<Moose::Deprecated> for more
329 =item You cannot pass C<< coerce => 1 >> unless the attribute's type constraint has a coercion
331 Previously, this was accepted, and it sort of worked, except that if you
332 attempted to set the attribute after the object was created, you would get a
335 Now you will get a warning when you attempt to define the attribute.
337 =item C<no Moose>, C<no Moose::Role>, and C<no Moose::Exporter> no longer unimport strict and warnings
339 This change was made in 1.05, and has now been reverted. We don't know if the
340 user has explicitly loaded strict or warnings on their own, and unimporting
341 them is just broken in that case.
343 =item Reversed logic when defining which options can be changed
345 L<Moose::Meta::Attribute> now allows all options to be changed in an
346 overridden attribute. The previous behaviour required each option to be
347 whitelisted using the C<legal_options_for_inheritance> method. This method has
348 been removed, and there is a new method, C<illegal_options_for_inheritance>,
349 which can now be used to prevent certain options from being changeable.
351 In addition, we only throw an error if the illegal option is actually
352 changed. If the superclass didn't specify this option at all when defining the
353 attribute, the subclass version can still add it as an option.
355 Example of overriding this in an attribute trait:
357 package Bar::Meta::Attribute;
360 has 'my_illegal_option' => (
365 around illegal_options_for_inheritance => sub {
366 return ( shift->(@_), qw/my_illegal_option/ );
375 =item L<Moose::Object/BUILD> methods are now called when calling C<new_object>
377 Previously, C<BUILD> methods would only be called from C<Moose::Object::new>,
378 but now they are also called when constructing an object via
379 C<Moose::Meta::Class::new_object>. C<BUILD> methods are an inherent part of the
380 object construction process, and this should make C<< $meta->new_object >>
381 actually usable without forcing people to use C<< $meta->name->new >>.
383 =item C<no Moose>, C<no Moose::Role>, and C<no Moose::Exporter> now unimport strict and warnings
385 In the interest of having C<no Moose> clean up everything that C<use Moose>
386 does in the calling scope, C<no Moose> (as well as all other
387 L<Moose::Exporter>-using modules) now unimports strict and warnings.
389 =item Metaclass compatibility checking and fixing should be much more robust
391 The L<metaclass compatibility|Moose/METACLASS COMPATIBILITY AND MOOSE> checking
392 and fixing algorithms have been completely rewritten, in both Class::MOP and
393 Moose. This should resolve many confusing errors when dealing with non-Moose
394 inheritance and with custom metaclasses for things like attributes,
395 constructors, etc. For correct code, the only thing that should require a
396 change is that custom error metaclasses must now inherit from
397 L<Moose::Error::Default>.
405 =item Moose::Meta::TypeConstraint::Class is_subtype_of behavior
407 Earlier versions of L<is_subtype_of|Moose::Meta::TypeConstraint::Class/is_subtype_of>
408 would incorrectly return true when called with itself, its own TC name or
409 its class name as an argument. (i.e. $foo_tc->is_subtype_of('Foo') == 1) This
410 behavior was a caused by C<isa> being checked before the class name. The old
411 behavior can be accessed with L<is_type_of|Moose::Meta::TypeConstraint::Class/is_type_of>
419 =item Moose::Meta::Attribute::Native::Trait::Code no longer creates reader methods by default
421 Earlier versions of L<Moose::Meta::Attribute::Native::Trait::Code> created
422 read-only accessors for the attributes it's been applied to, even if you didn't
423 ask for it with C<< is => 'ro' >>. This incorrect behaviour has now been fixed.
431 =item Moose::Util add_method_modifier behavior
433 add_method_modifier (and subsequently the sugar functions Moose::before,
434 Moose::after, and Moose::around) can now accept arrayrefs, with the same
435 behavior as lists. Types other than arrayref and regexp result in an error.
439 =head1 0.93_01 and 0.94
443 =item Moose::Util::MetaRole API has changed
445 The C<apply_metaclass_roles> function is now called C<apply_metaroles>. The
446 way arguments are supplied has been changed to force you to distinguish
447 between metaroles applied to L<Moose::Meta::Class> (and helpers) versus
448 L<Moose::Meta::Role>.
450 The old API still works, but will warn in a future release, and eventually be
453 =item Moose::Meta::Role has real attributes
455 The attributes returned by L<Moose::Meta::Role> are now instances of the
456 L<Moose::Meta::Role::Attribute> class, instead of bare hash references.
458 =item "no Moose" now removes C<blessed> and C<confess>
460 Moose is now smart enough to know exactly what it exported, even when it
461 re-exports functions from other packages. When you unimport Moose, it will
462 remove these functions from your namespace unless you I<also> imported them
463 directly from their respective packages.
465 If you have a C<no Moose> in your code I<before> you call C<blessed> or
466 C<confess>, your code will break. You can either move the C<no Moose> call
467 later in your code, or explicitly import the relevant functions from the
468 packages that provide them.
470 =item L<Moose::Exporter> is smarter about unimporting re-exports
472 The change above comes from a general improvement to L<Moose::Exporter>. It
473 will now unimport any function it exports, even if that function is a
474 re-export from another package.
476 =item Attributes in roles can no longer override class attributes with "+foo"
478 Previously, this worked more or less accidentally, because role attributes
479 weren't objects. This was never documented, but a few MooseX modules took
482 =item The composition_class_roles attribute in L<Moose::Meta::Role> is now a method
484 This was done to make it possible for roles to alter the the list of
485 composition class roles by applying a method modifiers. Previously, this was
486 an attribute and MooseX modules override it. Since that no longer works, this
489 This I<should> be an attribute, so this may switch back to being an attribute
490 in the future if we can figure out how to make this work.
498 =item Calling $object->new() is no longer deprecated
500 We decided to undeprecate this. Now it just works.
502 =item Both C<get_method_map> and C<get_attribute_map> is deprecated
504 These metaclass methods were never meant to be public, and they are both now
505 deprecated. The work around if you still need the functionality they provided
506 is to iterate over the list of names manually.
508 my %fields = map { $_ => $meta->get_attribute($_) } $meta->get_attribute_list;
510 This was actually a change in L<Class::MOP>, but this version of Moose
511 requires a version of L<Class::MOP> that includes said change.
519 =item Added Native delegation for Code refs
521 See L<Moose::Meta::Attribute::Native::Trait::Code> for details.
523 =item Calling $object->new() is deprecated
525 Moose has long supported this, but it's never really been documented, and we
526 don't think this is a good practice. If you want to construct an object from
527 an existing object, you should provide some sort of alternate constructor like
528 C<< $object->clone >>.
530 Calling C<< $object->new >> now issues a warning, and will be an error in a
533 =item Moose no longer warns if you call C<make_immutable> for a class with mutable ancestors
535 While in theory this is a good thing to warn about, we found so many
536 exceptions to this that doing this properly became quite problematic.
544 =item New Native delegation methods from L<List::Util> and L<List::MoreUtils>
546 In particular, we now have C<reduce>, C<shuffle>, C<uniq>, and C<natatime>.
548 =item The Moose::Exporter with_caller feature is now deprecated
550 Use C<with_meta> instead. The C<with_caller> option will start warning in a
553 =item Moose now warns if you call C<make_immutable> for a class with mutable ancestors
555 This is dangerous because modifying a class after a subclass has been
556 immutabilized will lead to incorrect results in the subclass, due to inlining,
557 caching, etc. This occasionally happens accidentally, when a class loads one
558 of its subclasses in the middle of its class definition, so pointing out that
559 this may cause issues should be helpful. Metaclasses (classes that inherit
560 from L<Class::MOP::Object>) are currently exempt from this check, since at the
561 moment we aren't very consistent about which metaclasses we immutabilize.
563 =item C<enum> and C<duck_type> now take arrayrefs for all forms
565 Previously, calling these functions with a list would take the first element of
566 the list as the type constraint name, and use the remainder as the enum values
567 or method names. This makes the interface inconsistent with the anon-type forms
568 of these functions (which must take an arrayref), and a free-form list where
569 the first value is sometimes special is hard to validate (and harder to give
570 reasonable error messages for). These functions have been changed to take
571 arrayrefs in all their forms - so, C<< enum 'My::Type' => [qw(foo bar)] >> is
572 now the preferred way to create an enum type constraint. The old syntax still
573 works for now, but it will hopefully be deprecated and removed in a future
580 L<Moose::Meta::Attribute::Native> has been moved into the Moose core from
581 L<MooseX::AttributeHelpers>. Major changes include:
585 =item C<traits>, not C<metaclass>
587 Method providers are only available via traits.
589 =item C<handles>, not C<provides> or C<curries>
591 The C<provides> syntax was like core Moose C<< handles => HASHREF >>
592 syntax, but with the keys and values reversed. This was confusing,
593 and AttributeHelpers now uses C<< handles => HASHREF >> in a way that
594 should be intuitive to anyone already familiar with how it is used for
597 The C<curries> functionality provided by AttributeHelpers has been
598 generalized to apply to all cases of C<< handles => HASHREF >>, though
599 not every piece of functionality has been ported (currying with a
600 CODEREF is not supported).
602 =item C<empty> is now C<is_empty>, and means empty, not non-empty
604 Previously, the C<empty> method provided by Arrays and Hashes returned true if
605 the attribute was B<not> empty (no elements). Now it returns true if the
606 attribute B<is> empty. It was also renamed to C<is_empty>, to reflect this.
608 =item C<find> was renamed to C<first>, and C<first> and C<last> were removed
610 L<List::Util> refers to the functionality that we used to provide under C<find>
611 as L<first|List::Util/first>, so that will likely be more familiar (and will
612 fit in better if we decide to add more List::Util functions). C<first> and
613 C<last> were removed, since their functionality is easily duplicated with
616 =item Helpers that take a coderef of one argument now use C<$_>
618 Subroutines passed as the first argument to C<first>, C<map>, and C<grep> now
619 receive their argument in C<$_> rather than as a parameter to the subroutine.
620 Helpers that take a coderef of two or more arguments remain using the argument
621 list (there are technical limitations to using C<$a> and C<$b> like C<sort>
624 See L<Moose::Meta::Attribute::Native> for the new documentation.
628 The C<alias> and C<excludes> role parameters have been renamed to C<-alias>
629 and C<-excludes>. The old names still work, but new code should use the new
630 names, and eventually the old ones will be deprecated and removed.
634 C<< use Moose -metaclass => 'Foo' >> now does alias resolution, just like
635 C<-traits> (and the C<metaclass> and C<traits> options to C<has>).
637 Added two functions C<meta_class_alias> and C<meta_attribute_alias> to
638 L<Moose::Util>, to simplify aliasing metaclasses and metatraits. This is
639 a wrapper around the old
641 package Moose::Meta::Class::Custom::Trait::FooTrait;
642 sub register_implementation { 'My::Meta::Trait' }
648 When an attribute generates I<no> accessors, we now warn. This is to help
649 users who forget the C<is> option. If you really do not want any accessors,
650 you can use C<< is => 'bare' >>. You can maintain back compat with older
651 versions of Moose by using something like:
653 ($Moose::VERSION >= 0.84 ? is => 'bare' : ())
655 When an accessor overwrites an existing method, we now warn. To work around
656 this warning (if you really must have this behavior), you can explicitly
657 remove the method before creating it as an accessor:
661 __PACKAGE__->meta->remove_method('foo');
667 When an unknown option is passed to C<has>, we now warn. You can silence
668 the warning by fixing your code. :)
670 The C<Role> type has been deprecated. On its own, it was useless,
671 since it just checked C<< $object->can('does') >>. If you were using
672 it as a parent type, just call C<role_type('Role::Name')> to create an
673 appropriate type instead.
677 C<use Moose::Exporter;> now imports C<strict> and C<warnings> into packages
682 C<DEMOLISHALL> and C<DEMOLISH> now receive an argument indicating whether or
683 not we are in global destruction.
687 Type constraints no longer run coercions for a value that already matches the
688 constraint. This may affect some (arguably buggy) edge case coercions that
689 rely on side effects in the C<via> clause.
693 L<Moose::Exporter> now accepts the C<-metaclass> option for easily
694 overriding the metaclass (without L<metaclass>). This works for classes
699 Added a C<duck_type> sugar function to L<Moose::Util::TypeConstraints>
700 to make integration with non-Moose classes easier. It simply checks if
701 C<< $obj->can() >> a list of methods.
703 A number of methods (mostly inherited from L<Class::MOP>) have been
704 renamed with a leading underscore to indicate their internal-ness. The
705 old method names will still work for a while, but will warn that the
706 method has been renamed. In a few cases, the method will be removed
707 entirely in the future. This may affect MooseX authors who were using
712 Calling C<subtype> with a name as the only argument now throws an
713 exception. If you want an anonymous subtype do:
715 my $subtype = subtype as 'Foo';
717 This is related to the changes in version 0.71_01.
719 The C<is_needed> method in L<Moose::Meta::Method::Destructor> is now
720 only usable as a class method. Previously, it worked as a class or
721 object method, with a different internal implementation for each
724 The internals of making a class immutable changed a lot in Class::MOP
725 0.78_02, and Moose's internals have changed along with it. The
726 external C<< $metaclass->make_immutable >> method still works the same
731 A mutable class accepted C<< Foo->new(undef) >> without complaint,
732 while an immutable class would blow up with an unhelpful error. Now,
733 in both cases we throw a helpful error instead.
735 This "feature" was originally added to allow for cases such as this:
743 return My::Class->new($args);
745 But we decided this is a bad idea and a little too magical, because it
746 can easily mask real errors.
750 Calling C<type> or C<subtype> without the sugar helpers (C<as>,
751 C<where>, C<message>) is now deprecated.
753 As a side effect, this meant we ended up using Perl prototypes on
754 C<as>, and code like this will no longer work:
756 use Moose::Util::TypeConstraints;
757 use Declare::Constraints::Simple -All;
759 subtype 'ArrayOfInts'
761 => IsArrayRef(IsInt);
763 Instead it must be changed to this:
768 where => IsArrayRef(IsInt)
772 If you want to maintain backwards compat with older versions of Moose,
773 you must explicitly test Moose's C<VERSION>:
775 if ( Moose->VERSION < 0.71_01 ) {
776 subtype 'ArrayOfInts'
778 => IsArrayRef(IsInt);
784 where => IsArrayRef(IsInt)
791 We no longer pass the meta-attribute object as a final argument to
792 triggers. This actually changed for inlined code a while back, but the
793 non-inlined version and the docs were still out of date.
795 If by some chance you actually used this feature, the workaround is
796 simple. You fetch the attribute object from out of the C<$self>
797 that is passed as the first argument to trigger, like so:
803 my ( $self, $value ) = @_;
804 my $attr = $self->meta->find_attribute_by_name('foo');
812 If you created a subtype and passed a parent that Moose didn't know
813 about, it simply ignored the parent. Now it automatically creates the
814 parent as a class type. This may not be what you want, but is less
817 You could declare a name with subtype such as "Foo!Bar". Moose would
818 accept this allowed, but if you used it in a parameterized type such
819 as "ArrayRef[Foo!Bar]" it wouldn't work. We now do some vetting on
820 names created via the sugar functions, so that they can only contain
821 alphanumerics, ":", and ".".
825 Methods created via an attribute can now fulfill a C<requires>
826 declaration for a role. Honestly we don't know why Stevan didn't make
827 this work originally, he was just insane or something.
829 Stack traces from inlined code will now report the line and file as
830 being in your class, as opposed to in Moose guts.
834 When a class does not provide all of a role's required methods, the
835 error thrown now mentions all of the missing methods, as opposed to
836 just the first missing method.
838 Moose will no longer inline a constructor for your class unless it
839 inherits its constructor from Moose::Object, and will warn when it
840 doesn't inline. If you want to force inlining anyway, pass
841 C<< replace_constructor => 1 >> to C<make_immutable>.
843 If you want to get rid of the warning, pass C<< inline_constructor =>
848 Removed the (deprecated) C<make_immutable> keyword.
850 Removing an attribute from a class now also removes delegation
851 (C<handles>) methods installed for that attribute. This is correct
852 behavior, but if you were wrongly relying on it you might get bit.
856 Roles now add methods by calling C<add_method>, not
857 C<alias_method>. They make sure to always provide a method object,
858 which will be cloned internally. This means that it is now possible to
859 track the source of a method provided by a role, and even follow its
860 history through intermediate roles. This means that methods added by
861 a role now show up when looking at a class's method list/map.
863 Parameter and Union args are now sorted, this makes Int|Str the same
864 constraint as Str|Int. Also, incoming type constraint strings are
865 normalized to remove all whitespace differences. This is mostly for
866 internals and should not affect outside code.
868 L<Moose::Exporter> will no longer remove a subroutine that the
869 exporting package re-exports. Moose re-exports the Carp::confess
870 function, among others. The reasoning is that we cannot know whether
871 you have also explicitly imported those functions for your own use, so
872 we err on the safe side and always keep them.
876 C<Moose::init_meta> should now be called as a method.
878 New modules for extension writers, L<Moose::Exporter> and
879 L<Moose::Util::MetaRole>.
883 Implemented metaclass traits (and wrote a recipe for it):
885 use Moose -traits => 'Foo'
887 This should make writing small Moose extensions a little
892 Fixed C<coerce> to accept anon types just like C<subtype> can.
895 coerce $some_anon_type => from 'Str' => via { ... };
899 Added C<BUILDARGS>, a new step in C<< Moose::Object->new() >>.
903 Fixed how the C<< is => (ro|rw) >> works with custom defined
904 C<reader>, C<writer> and C<accessor> options. See the below table for
907 is => ro, writer => _foo # turns into (reader => foo, writer => _foo)
908 is => rw, writer => _foo # turns into (reader => foo, writer => _foo)
909 is => rw, accessor => _foo # turns into (accessor => _foo)
910 is => ro, accessor => _foo # error, accesor is rw
914 The C<before/around/after> method modifiers now support regexp
915 matching of method names. NOTE: this only works for classes, it is
916 currently not supported in roles, but, ... patches welcome.
918 The C<has> keyword for roles now accepts the same array ref form that
919 L<Moose>.pm does for classes.
921 A trigger on a read-only attribute is no longer an error, as it's
922 useful to trigger off of the constructor.
924 Subtypes of parameterizable types now are parameterizable types
929 Fixed issue where C<DEMOLISHALL> was eating the value in C<$@>, and so
930 not working correctly. It still kind of eats them, but so does vanilla
935 Inherited attributes may now be extended without restriction on the
936 type ('isa', 'does').
938 The entire set of Moose::Meta::TypeConstraint::* classes were
939 refactored in this release. If you were relying on their internals you
940 should test your code carefully.
944 Documenting the use of '+name' with attributes that come from recently
945 composed roles. It makes sense, people are using it, and so why not
946 just officially support it.
948 The C<< Moose::Meta::Class->create >> method now supports roles.
950 It is now possible to make anonymous enum types by passing C<enum> an
951 array reference instead of the C<< enum $name => @values >>.
955 Added the C<make_immutable> keyword as a shortcut to calling
956 C<make_immutable> on the meta object. This eventually got removed!
958 Made C<< init_arg => undef >> work in Moose. This means "do not accept
959 a constructor parameter for this attribute".
961 Type errors now use the provided message. Prior to this release they
966 Moose is now a postmodern object system :)
968 The Role system was completely refactored. It is 100% backwards
969 compat, but the internals were totally changed. If you relied on the
970 internals then you are advised to test carefully.
972 Added method exclusion and aliasing for Roles in this release.
974 Added the L<Moose::Util::TypeConstraints::OptimizedConstraints>
977 Passing a list of values to an accessor (which is only expecting one
978 value) used to be silently ignored, now it throws an error.
982 Added parameterized types and did a pretty heavy refactoring of the
983 type constraint system.
985 Better framework extensibility and better support for "making your own
988 =head1 0.25 or before
990 Honestly, you shouldn't be using versions of Moose that are this old,
991 so many bug fixes and speed improvements have been made you would be
992 crazy to not upgrade.
994 Also, I am tired of going through the Changelog so I am stopping here,
995 if anyone would like to continue this please feel free.