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 Hand-optimized type constraint code is deprecated in favor of inlining
28 Moose allows you to provide a hand-optimized version of a type constraint's
29 subroutine reference. This version allows type constraints to generate inline
30 code, and you should use this inlining instead of providing a hand-optimized
33 This affects the C<optimize_as> sub exported by
34 L<Moose::Util::TypeConstraints>. Use C<inline_as> instead.
36 This will start warning in the 2.0300 release.
42 =item More useful type constraint error messages
44 If you have L<Devel::PartialDump> version 0.14 or higher installed, Moose's
45 type constraint error messages will use it to display the invalid value, rather
46 than just displaying it directly. This will generally be much more useful. For
47 instance, instead of this:
49 Attribute (foo) does not pass the type constraint because: Validation failed for 'ArrayRef[Int]' with value ARRAY(0x275eed8)
51 the error message will instead look like
53 Attribute (foo) does not pass the type constraint because: Validation failed for 'ArrayRef[Int]' with value [ "a" ]
55 Note that L<Devel::PartialDump> can't be made a direct dependency at the
56 moment, because it uses Moose itself, but we're considering options to make
65 =item Roles have their own default attribute metaclass
67 Previously, when a role was applied to a class, it would use the attribute
68 metaclass defined in the class when copying over the attributes in the role.
69 This was wrong, because for instance, using L<MooseX::FollowPBP> in the class
70 would end up renaming all of the accessors generated by the role, some of which
71 may be being called in the role, causing it to break. Roles now keep track of
72 their own attribute metaclass to use by default when being applied to a class
73 (defaulting to Moose::Meta::Attribute). This is modifiable using
74 L<Moose::Util::MetaRole> by passing the C<applied_attribute> key to the
75 C<role_metaroles> option, as in:
77 Moose::Util::MetaRole::apply_metaroles(
80 attribute => ['My::Meta::Role::Attribute'],
83 applied_attribute => ['My::Meta::Role::Attribute'],
87 =item Class::MOP has been folded into the Moose dist
89 Moose and Class::MOP are tightly related enough that they have always had to be
90 kept pretty closely in step in terms of versions. Making them into a single
91 dist should simplify the upgrade process for users, as it should no longer be
92 possible to upgrade one without the other and potentially cause issues. No
93 functionality has changed, and this should be entirely transparent.
95 =item Moose's conflict checking is more robust and useful
97 There are two parts to this. The most useful one right now is that Moose will
98 ship with a C<moose-outdated> script, which can be run at any point to list the
99 modules which are installed that conflict with the installed version of Moose.
100 After upgrading Moose, running C<moose-outdated | cpanm> should be sufficient
101 to ensure that all of the Moose extensions you use will continue to work.
103 The other part is that Moose's C<META.json> file will also specify the
104 conflicts under the C<x_conflicts> key. We are working with the Perl tool chain
105 developers to try to get conflicts support added to CPAN clients, and if/when
106 that happens, the metadata already exists, and so the conflict checking will
109 =item Most deprecated APIs/features are slated for removal in Moose 2.0200
111 Most of the deprecated APIs and features in Moose will start throwing an error
112 in Moose 2.0200. Some of the features will go away entirely, and some will
113 simply throw an error.
115 The things on the chopping block are:
119 =item * Old public methods in Class::MOP and Moose
121 This includes things like C<< Class::MOP::Class->get_attribute_map >>, C<<
122 Class::MOP::Class->construct_instance >>, and many others. These were
123 deprecated in L<Class::MOP> 0.80_01, released on April 5, 2009.
125 These methods will be removed entirely in Moose 2.0200.
127 =item * Old public functions in Class::MOP
129 This include C<Class::MOP::subname>, C<Class::MOP::in_global_destruction>, and
130 the C<Class::MOP::HAS_ISAREV> constant. The first two were deprecated in 0.84,
131 and the last in 0.80. Class::MOP 0.84 was released on May 12, 2009.
133 These functions will be removed entirely in Moose 2.0200.
135 =item * The C<alias> and C<excludes> option for role composition
137 These were renamed to C<-alias> and C<-excludes> in Moose 0.89, released on
140 Passing these will throw an error in Moose 2.0200.
142 =item * The old L<Moose::Util::MetaRole> API
144 This include the C<apply_metaclass_roles()> function, as well as passing the
145 C<for_class> or any key ending in C<_roles> to C<apply_metaroles()>. This was
146 deprecated in Moose 0.93_01, released on January 4, 2010.
148 These will all throw an error in Moose 2.0200.
150 =item * Passing plain lists to C<type()> or C<subtype()>
152 The old API for these functions allowed you to pass a plain list of parameter,
153 rather than a list of hash references (which is what C<as()>, C<where>,
154 etc. return). This was deprecated in Moose 0.71_01, released on February 22,
157 This will throw an error in Moose 2.0200.
159 =item * The Role subtype
161 This subtype was deprecated in Moose 0.84, released on June 26, 2009.
163 This will be removed entirely in Moose 2.0200.
173 =item * New release policy
175 As of the 2.0 release, Moose now has an official release and support policy,
176 documented in L<Moose::Manual::Support>. All API changes will now go through a
177 deprecation cycle of at least one year, after which the deprecated API can be
178 removed. Deprecations and removals will only happen in major releases.
180 In between major releases, we will still make minor releases to add new
181 features, fix bugs, update documentation, etc.
189 =item Configurable stacktraces
191 Classes which use the L<Moose::Error::Default> error class can now have
192 stacktraces disabled by setting the C<MOOSE_ERROR_STYLE> env var to C<croak>.
193 This is experimental, fairly incomplete, and won't work in all cases (because
194 Moose's error system in general is all of these things), but this should allow
195 for reducing at least some of the verbosity in most cases.
203 =item Native Delegations
205 In previous versions of Moose, the Native delegations were created as
206 closures. The generated code was often quite slow compared to doing the same
207 thing by hand. For example, the Array's push delegation ended up doing
210 push @{ $self->$reader() }, @_;
212 If the attribute was created without a reader, the C<$reader> sub reference
213 followed a very slow code path. Even with a reader, this is still slower than
216 Native delegations are now generated as inline code, just like other
217 accessors, so we can access the slot directly.
219 In addition, native traits now do proper constraint checking in all cases. In
220 particular, constraint checking has been improved for array and hash
221 references. Previously, only the I<contained> type (the C<Str> in
222 C<HashRef[Str]>) would be checked when a new value was added to the
223 collection. However, if there was a constraint that applied to the whole
224 value, this was never checked.
226 In addition, coercions are now called on the whole value.
228 The delegation methods now do more argument checking. All of the methods check
229 that a valid number of arguments were passed to the method. In addition, the
230 delegation methods check that the arguments are sane (array indexes, hash
231 keys, numbers, etc.) when applicable. We have tried to emulate the behavior of
232 Perl builtins as much as possible.
234 Finally, triggers are called whenever the value of the attribute is changed by
237 These changes are only likely to break code in a few cases.
239 The inlining code may or may not preserve the original reference when changes
240 are made. In some cases, methods which change the value may replace it
241 entirely. This will break tied values.
243 If you have a typed arrayref or hashref attribute where the type enforces a
244 constraint on the whole collection, this constraint will now be checked. It's
245 possible that code which previously ran without errors will now cause the
246 constraint to fail. However, presumably this is a good thing ;)
248 If you are passing invalid arguments to a delegation which were previously
249 being ignored, these calls will now fail.
251 If your code relied on the trigger only being called for a regular writer,
252 that may cause problems.
254 As always, you are encouraged to test before deploying the latest version of
257 =item Defaults is and default for String, Counter, and Bool
259 A few native traits (String, Counter, Bool) provide default values of "is" and
260 "default" when you created an attribute. Allowing them to provide these values
261 is now deprecated. Supply the value yourself when creating the attribute.
263 =item The C<meta> method
265 Moose and Class::MOP have been cleaned up internally enough to make the
266 C<meta> method that you get by default optional. C<use Moose> and
267 C<use Moose::Role> now can take an additional C<-meta_name> option, which
268 tells Moose what name to use when installing the C<meta> method. Passing
269 C<undef> to this option suppresses generation of the C<meta> method
270 entirely. This should be useful for users of modules which also use a C<meta>
271 method or function, such as L<Curses> or L<Rose::DB::Object>.
279 =item All deprecated features now warn
281 Previously, deprecation mostly consisted of simply saying "X is deprecated" in
282 the Changes file. We were not very consistent about actually warning. Now, all
283 deprecated features still present in Moose actually give a warning. The
284 warning is issued once per calling package. See L<Moose::Deprecated> for more
287 =item You cannot pass C<< coerce => 1 >> unless the attribute's type constraint has a coercion
289 Previously, this was accepted, and it sort of worked, except that if you
290 attempted to set the attribute after the object was created, you would get a
293 Now you will get a warning when you attempt to define the attribute.
295 =item C<no Moose>, C<no Moose::Role>, and C<no Moose::Exporter> no longer unimport strict and warnings
297 This change was made in 1.05, and has now been reverted. We don't know if the
298 user has explicitly loaded strict or warnings on their own, and unimporting
299 them is just broken in that case.
301 =item Reversed logic when defining which options can be changed
303 L<Moose::Meta::Attribute> now allows all options to be changed in an
304 overridden attribute. The previous behaviour required each option to be
305 whitelisted using the C<legal_options_for_inheritance> method. This method has
306 been removed, and there is a new method, C<illegal_options_for_inheritance>,
307 which can now be used to prevent certain options from being changeable.
309 In addition, we only throw an error if the illegal option is actually
310 changed. If the superclass didn't specify this option at all when defining the
311 attribute, the subclass version can still add it as an option.
313 Example of overriding this in an attribute trait:
315 package Bar::Meta::Attribute;
318 has 'my_illegal_option' => (
323 around illegal_options_for_inheritance => sub {
324 return ( shift->(@_), qw/my_illegal_option/ );
333 =item L<Moose::Object/BUILD> methods are now called when calling C<new_object>
335 Previously, C<BUILD> methods would only be called from C<Moose::Object::new>,
336 but now they are also called when constructing an object via
337 C<Moose::Meta::Class::new_object>. C<BUILD> methods are an inherent part of the
338 object construction process, and this should make C<< $meta->new_object >>
339 actually usable without forcing people to use C<< $meta->name->new >>.
341 =item C<no Moose>, C<no Moose::Role>, and C<no Moose::Exporter> now unimport strict and warnings
343 In the interest of having C<no Moose> clean up everything that C<use Moose>
344 does in the calling scope, C<no Moose> (as well as all other
345 L<Moose::Exporter>-using modules) now unimports strict and warnings.
347 =item Metaclass compatibility checking and fixing should be much more robust
349 The L<metaclass compatibility|Moose/METACLASS COMPATIBILITY AND MOOSE> checking
350 and fixing algorithms have been completely rewritten, in both Class::MOP and
351 Moose. This should resolve many confusing errors when dealing with non-Moose
352 inheritance and with custom metaclasses for things like attributes,
353 constructors, etc. For correct code, the only thing that should require a
354 change is that custom error metaclasses must now inherit from
355 L<Moose::Error::Default>.
363 =item Moose::Meta::TypeConstraint::Class is_subtype_of behavior
365 Earlier versions of L<is_subtype_of|Moose::Meta::TypeConstraint::Class/is_subtype_of>
366 would incorrectly return true when called with itself, its own TC name or
367 its class name as an argument. (i.e. $foo_tc->is_subtype_of('Foo') == 1) This
368 behavior was a caused by C<isa> being checked before the class name. The old
369 behavior can be accessed with L<is_type_of|Moose::Meta::TypeConstraint::Class/is_type_of>
377 =item Moose::Meta::Attribute::Native::Trait::Code no longer creates reader methods by default
379 Earlier versions of L<Moose::Meta::Attribute::Native::Trait::Code> created
380 read-only accessors for the attributes it's been applied to, even if you didn't
381 ask for it with C<< is => 'ro' >>. This incorrect behaviour has now been fixed.
389 =item Moose::Util add_method_modifier behavior
391 add_method_modifier (and subsequently the sugar functions Moose::before,
392 Moose::after, and Moose::around) can now accept arrayrefs, with the same
393 behavior as lists. Types other than arrayref and regexp result in an error.
397 =head1 0.93_01 and 0.94
401 =item Moose::Util::MetaRole API has changed
403 The C<apply_metaclass_roles> function is now called C<apply_metaroles>. The
404 way arguments are supplied has been changed to force you to distinguish
405 between metaroles applied to L<Moose::Meta::Class> (and helpers) versus
406 L<Moose::Meta::Role>.
408 The old API still works, but will warn in a future release, and eventually be
411 =item Moose::Meta::Role has real attributes
413 The attributes returned by L<Moose::Meta::Role> are now instances of the
414 L<Moose::Meta::Role::Attribute> class, instead of bare hash references.
416 =item "no Moose" now removes C<blessed> and C<confess>
418 Moose is now smart enough to know exactly what it exported, even when it
419 re-exports functions from other packages. When you unimport Moose, it will
420 remove these functions from your namespace unless you I<also> imported them
421 directly from their respective packages.
423 If you have a C<no Moose> in your code I<before> you call C<blessed> or
424 C<confess>, your code will break. You can either move the C<no Moose> call
425 later in your code, or explicitly import the relevant functions from the
426 packages that provide them.
428 =item L<Moose::Exporter> is smarter about unimporting re-exports
430 The change above comes from a general improvement to L<Moose::Exporter>. It
431 will now unimport any function it exports, even if that function is a
432 re-export from another package.
434 =item Attributes in roles can no longer override class attributes with "+foo"
436 Previously, this worked more or less accidentally, because role attributes
437 weren't objects. This was never documented, but a few MooseX modules took
440 =item The composition_class_roles attribute in L<Moose::Meta::Role> is now a method
442 This was done to make it possible for roles to alter the the list of
443 composition class roles by applying a method modifiers. Previously, this was
444 an attribute and MooseX modules override it. Since that no longer works, this
447 This I<should> be an attribute, so this may switch back to being an attribute
448 in the future if we can figure out how to make this work.
456 =item Calling $object->new() is no longer deprecated
458 We decided to undeprecate this. Now it just works.
460 =item Both C<get_method_map> and C<get_attribute_map> is deprecated
462 These metaclass methods were never meant to be public, and they are both now
463 deprecated. The work around if you still need the functionality they provided
464 is to iterate over the list of names manually.
466 my %fields = map { $_ => $meta->get_attribute($_) } $meta->get_attribute_list;
468 This was actually a change in L<Class::MOP>, but this version of Moose
469 requires a version of L<Class::MOP> that includes said change.
477 =item Added Native delegation for Code refs
479 See L<Moose::Meta::Attribute::Native::Trait::Code> for details.
481 =item Calling $object->new() is deprecated
483 Moose has long supported this, but it's never really been documented, and we
484 don't think this is a good practice. If you want to construct an object from
485 an existing object, you should provide some sort of alternate constructor like
486 C<< $object->clone >>.
488 Calling C<< $object->new >> now issues a warning, and will be an error in a
491 =item Moose no longer warns if you call C<make_immutable> for a class with mutable ancestors
493 While in theory this is a good thing to warn about, we found so many
494 exceptions to this that doing this properly became quite problematic.
502 =item New Native delegation methods from L<List::Util> and L<List::MoreUtils>
504 In particular, we now have C<reduce>, C<shuffle>, C<uniq>, and C<natatime>.
506 =item The Moose::Exporter with_caller feature is now deprecated
508 Use C<with_meta> instead. The C<with_caller> option will start warning in a
511 =item Moose now warns if you call C<make_immutable> for a class with mutable ancestors
513 This is dangerous because modifying a class after a subclass has been
514 immutabilized will lead to incorrect results in the subclass, due to inlining,
515 caching, etc. This occasionally happens accidentally, when a class loads one
516 of its subclasses in the middle of its class definition, so pointing out that
517 this may cause issues should be helpful. Metaclasses (classes that inherit
518 from L<Class::MOP::Object>) are currently exempt from this check, since at the
519 moment we aren't very consistent about which metaclasses we immutabilize.
521 =item C<enum> and C<duck_type> now take arrayrefs for all forms
523 Previously, calling these functions with a list would take the first element of
524 the list as the type constraint name, and use the remainder as the enum values
525 or method names. This makes the interface inconsistent with the anon-type forms
526 of these functions (which must take an arrayref), and a free-form list where
527 the first value is sometimes special is hard to validate (and harder to give
528 reasonable error messages for). These functions have been changed to take
529 arrayrefs in all their forms - so, C<< enum 'My::Type' => [qw(foo bar)] >> is
530 now the preferred way to create an enum type constraint. The old syntax still
531 works for now, but it will hopefully be deprecated and removed in a future
538 L<Moose::Meta::Attribute::Native> has been moved into the Moose core from
539 L<MooseX::AttributeHelpers>. Major changes include:
543 =item C<traits>, not C<metaclass>
545 Method providers are only available via traits.
547 =item C<handles>, not C<provides> or C<curries>
549 The C<provides> syntax was like core Moose C<< handles => HASHREF >>
550 syntax, but with the keys and values reversed. This was confusing,
551 and AttributeHelpers now uses C<< handles => HASHREF >> in a way that
552 should be intuitive to anyone already familiar with how it is used for
555 The C<curries> functionality provided by AttributeHelpers has been
556 generalized to apply to all cases of C<< handles => HASHREF >>, though
557 not every piece of functionality has been ported (currying with a
558 CODEREF is not supported).
560 =item C<empty> is now C<is_empty>, and means empty, not non-empty
562 Previously, the C<empty> method provided by Arrays and Hashes returned true if
563 the attribute was B<not> empty (no elements). Now it returns true if the
564 attribute B<is> empty. It was also renamed to C<is_empty>, to reflect this.
566 =item C<find> was renamed to C<first>, and C<first> and C<last> were removed
568 L<List::Util> refers to the functionality that we used to provide under C<find>
569 as L<first|List::Util/first>, so that will likely be more familiar (and will
570 fit in better if we decide to add more List::Util functions). C<first> and
571 C<last> were removed, since their functionality is easily duplicated with
574 =item Helpers that take a coderef of one argument now use C<$_>
576 Subroutines passed as the first argument to C<first>, C<map>, and C<grep> now
577 receive their argument in C<$_> rather than as a parameter to the subroutine.
578 Helpers that take a coderef of two or more arguments remain using the argument
579 list (there are technical limitations to using C<$a> and C<$b> like C<sort>
582 See L<Moose::Meta::Attribute::Native> for the new documentation.
586 The C<alias> and C<excludes> role parameters have been renamed to C<-alias>
587 and C<-excludes>. The old names still work, but new code should use the new
588 names, and eventually the old ones will be deprecated and removed.
592 C<< use Moose -metaclass => 'Foo' >> now does alias resolution, just like
593 C<-traits> (and the C<metaclass> and C<traits> options to C<has>).
595 Added two functions C<meta_class_alias> and C<meta_attribute_alias> to
596 L<Moose::Util>, to simplify aliasing metaclasses and metatraits. This is
597 a wrapper around the old
599 package Moose::Meta::Class::Custom::Trait::FooTrait;
600 sub register_implementation { 'My::Meta::Trait' }
606 When an attribute generates I<no> accessors, we now warn. This is to help
607 users who forget the C<is> option. If you really do not want any accessors,
608 you can use C<< is => 'bare' >>. You can maintain back compat with older
609 versions of Moose by using something like:
611 ($Moose::VERSION >= 0.84 ? is => 'bare' : ())
613 When an accessor overwrites an existing method, we now warn. To work around
614 this warning (if you really must have this behavior), you can explicitly
615 remove the method before creating it as an accessor:
619 __PACKAGE__->meta->remove_method('foo');
625 When an unknown option is passed to C<has>, we now warn. You can silence
626 the warning by fixing your code. :)
628 The C<Role> type has been deprecated. On its own, it was useless,
629 since it just checked C<< $object->can('does') >>. If you were using
630 it as a parent type, just call C<role_type('Role::Name')> to create an
631 appropriate type instead.
635 C<use Moose::Exporter;> now imports C<strict> and C<warnings> into packages
640 C<DEMOLISHALL> and C<DEMOLISH> now receive an argument indicating whether or
641 not we are in global destruction.
645 Type constraints no longer run coercions for a value that already matches the
646 constraint. This may affect some (arguably buggy) edge case coercions that
647 rely on side effects in the C<via> clause.
651 L<Moose::Exporter> now accepts the C<-metaclass> option for easily
652 overriding the metaclass (without L<metaclass>). This works for classes
657 Added a C<duck_type> sugar function to L<Moose::Util::TypeConstraints>
658 to make integration with non-Moose classes easier. It simply checks if
659 C<< $obj->can() >> a list of methods.
661 A number of methods (mostly inherited from L<Class::MOP>) have been
662 renamed with a leading underscore to indicate their internal-ness. The
663 old method names will still work for a while, but will warn that the
664 method has been renamed. In a few cases, the method will be removed
665 entirely in the future. This may affect MooseX authors who were using
670 Calling C<subtype> with a name as the only argument now throws an
671 exception. If you want an anonymous subtype do:
673 my $subtype = subtype as 'Foo';
675 This is related to the changes in version 0.71_01.
677 The C<is_needed> method in L<Moose::Meta::Method::Destructor> is now
678 only usable as a class method. Previously, it worked as a class or
679 object method, with a different internal implementation for each
682 The internals of making a class immutable changed a lot in Class::MOP
683 0.78_02, and Moose's internals have changed along with it. The
684 external C<< $metaclass->make_immutable >> method still works the same
689 A mutable class accepted C<< Foo->new(undef) >> without complaint,
690 while an immutable class would blow up with an unhelpful error. Now,
691 in both cases we throw a helpful error instead.
693 This "feature" was originally added to allow for cases such as this:
701 return My::Class->new($args);
703 But we decided this is a bad idea and a little too magical, because it
704 can easily mask real errors.
708 Calling C<type> or C<subtype> without the sugar helpers (C<as>,
709 C<where>, C<message>) is now deprecated.
711 As a side effect, this meant we ended up using Perl prototypes on
712 C<as>, and code like this will no longer work:
714 use Moose::Util::TypeConstraints;
715 use Declare::Constraints::Simple -All;
717 subtype 'ArrayOfInts'
719 => IsArrayRef(IsInt);
721 Instead it must be changed to this:
726 where => IsArrayRef(IsInt)
730 If you want to maintain backwards compat with older versions of Moose,
731 you must explicitly test Moose's C<VERSION>:
733 if ( Moose->VERSION < 0.71_01 ) {
734 subtype 'ArrayOfInts'
736 => IsArrayRef(IsInt);
742 where => IsArrayRef(IsInt)
749 We no longer pass the meta-attribute object as a final argument to
750 triggers. This actually changed for inlined code a while back, but the
751 non-inlined version and the docs were still out of date.
753 If by some chance you actually used this feature, the workaround is
754 simple. You fetch the attribute object from out of the C<$self>
755 that is passed as the first argument to trigger, like so:
761 my ( $self, $value ) = @_;
762 my $attr = $self->meta->find_attribute_by_name('foo');
770 If you created a subtype and passed a parent that Moose didn't know
771 about, it simply ignored the parent. Now it automatically creates the
772 parent as a class type. This may not be what you want, but is less
775 You could declare a name with subtype such as "Foo!Bar". Moose would
776 accept this allowed, but if you used it in a parameterized type such
777 as "ArrayRef[Foo!Bar]" it wouldn't work. We now do some vetting on
778 names created via the sugar functions, so that they can only contain
779 alphanumerics, ":", and ".".
783 Methods created via an attribute can now fulfill a C<requires>
784 declaration for a role. Honestly we don't know why Stevan didn't make
785 this work originally, he was just insane or something.
787 Stack traces from inlined code will now report the line and file as
788 being in your class, as opposed to in Moose guts.
792 When a class does not provide all of a role's required methods, the
793 error thrown now mentions all of the missing methods, as opposed to
794 just the first missing method.
796 Moose will no longer inline a constructor for your class unless it
797 inherits its constructor from Moose::Object, and will warn when it
798 doesn't inline. If you want to force inlining anyway, pass
799 C<< replace_constructor => 1 >> to C<make_immutable>.
801 If you want to get rid of the warning, pass C<< inline_constructor =>
806 Removed the (deprecated) C<make_immutable> keyword.
808 Removing an attribute from a class now also removes delegation
809 (C<handles>) methods installed for that attribute. This is correct
810 behavior, but if you were wrongly relying on it you might get bit.
814 Roles now add methods by calling C<add_method>, not
815 C<alias_method>. They make sure to always provide a method object,
816 which will be cloned internally. This means that it is now possible to
817 track the source of a method provided by a role, and even follow its
818 history through intermediate roles. This means that methods added by
819 a role now show up when looking at a class's method list/map.
821 Parameter and Union args are now sorted, this makes Int|Str the same
822 constraint as Str|Int. Also, incoming type constraint strings are
823 normalized to remove all whitespace differences. This is mostly for
824 internals and should not affect outside code.
826 L<Moose::Exporter> will no longer remove a subroutine that the
827 exporting package re-exports. Moose re-exports the Carp::confess
828 function, among others. The reasoning is that we cannot know whether
829 you have also explicitly imported those functions for your own use, so
830 we err on the safe side and always keep them.
834 C<Moose::init_meta> should now be called as a method.
836 New modules for extension writers, L<Moose::Exporter> and
837 L<Moose::Util::MetaRole>.
841 Implemented metaclass traits (and wrote a recipe for it):
843 use Moose -traits => 'Foo'
845 This should make writing small Moose extensions a little
850 Fixed C<coerce> to accept anon types just like C<subtype> can.
853 coerce $some_anon_type => from 'Str' => via { ... };
857 Added C<BUILDARGS>, a new step in C<< Moose::Object->new() >>.
861 Fixed how the C<< is => (ro|rw) >> works with custom defined
862 C<reader>, C<writer> and C<accessor> options. See the below table for
865 is => ro, writer => _foo # turns into (reader => foo, writer => _foo)
866 is => rw, writer => _foo # turns into (reader => foo, writer => _foo)
867 is => rw, accessor => _foo # turns into (accessor => _foo)
868 is => ro, accessor => _foo # error, accesor is rw
872 The C<before/around/after> method modifiers now support regexp
873 matching of method names. NOTE: this only works for classes, it is
874 currently not supported in roles, but, ... patches welcome.
876 The C<has> keyword for roles now accepts the same array ref form that
877 L<Moose>.pm does for classes.
879 A trigger on a read-only attribute is no longer an error, as it's
880 useful to trigger off of the constructor.
882 Subtypes of parameterizable types now are parameterizable types
887 Fixed issue where C<DEMOLISHALL> was eating the value in C<$@>, and so
888 not working correctly. It still kind of eats them, but so does vanilla
893 Inherited attributes may now be extended without restriction on the
894 type ('isa', 'does').
896 The entire set of Moose::Meta::TypeConstraint::* classes were
897 refactored in this release. If you were relying on their internals you
898 should test your code carefully.
902 Documenting the use of '+name' with attributes that come from recently
903 composed roles. It makes sense, people are using it, and so why not
904 just officially support it.
906 The C<< Moose::Meta::Class->create >> method now supports roles.
908 It is now possible to make anonymous enum types by passing C<enum> an
909 array reference instead of the C<< enum $name => @values >>.
913 Added the C<make_immutable> keyword as a shortcut to calling
914 C<make_immutable> on the meta object. This eventually got removed!
916 Made C<< init_arg => undef >> work in Moose. This means "do not accept
917 a constructor parameter for this attribute".
919 Type errors now use the provided message. Prior to this release they
924 Moose is now a postmodern object system :)
926 The Role system was completely refactored. It is 100% backwards
927 compat, but the internals were totally changed. If you relied on the
928 internals then you are advised to test carefully.
930 Added method exclusion and aliasing for Roles in this release.
932 Added the L<Moose::Util::TypeConstraints::OptimizedConstraints>
935 Passing a list of values to an accessor (which is only expecting one
936 value) used to be silently ignored, now it throws an error.
940 Added parameterized types and did a pretty heavy refactoring of the
941 type constraint system.
943 Better framework extensibility and better support for "making your own
946 =head1 0.25 or before
948 Honestly, you shouldn't be using versions of Moose that are this old,
949 so many bug fixes and speed improvements have been made you would be
950 crazy to not upgrade.
952 Also, I am tired of going through the Changelog so I am stopping here,
953 if anyone would like to continue this please feel free.