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 causes a deprecation warning
28 If you provide an optimized sub ref for a type constraint, this now causes a
29 deprecation warning. Typically, this comes from passing an C<optimize_as>
30 parameter to C<subtype>, but it could also happen if you create a
31 L<Moose::Meta::TypeConstraint> object directly.
33 Use the inlining feature (C<inline_as>) added in 2.0100 instead.
41 =item Hand-optimized type constraint code is deprecated in favor of inlining
43 Moose allows you to provide a hand-optimized version of a type constraint's
44 subroutine reference. This version allows type constraints to generate inline
45 code, and you should use this inlining instead of providing a hand-optimized
48 This affects the C<optimize_as> sub exported by
49 L<Moose::Util::TypeConstraints>. Use C<inline_as> instead.
51 This will start warning in the 2.0300 release.
57 =item More useful type constraint error messages
59 If you have L<Devel::PartialDump> version 0.14 or higher installed, Moose's
60 type constraint error messages will use it to display the invalid value, rather
61 than just displaying it directly. This will generally be much more useful. For
62 instance, instead of this:
64 Attribute (foo) does not pass the type constraint because: Validation failed for 'ArrayRef[Int]' with value ARRAY(0x275eed8)
66 the error message will instead look like
68 Attribute (foo) does not pass the type constraint because: Validation failed for 'ArrayRef[Int]' with value [ "a" ]
70 Note that L<Devel::PartialDump> can't be made a direct dependency at the
71 moment, because it uses Moose itself, but we're considering options to make
80 =item Roles have their own default attribute metaclass
82 Previously, when a role was applied to a class, it would use the attribute
83 metaclass defined in the class when copying over the attributes in the role.
84 This was wrong, because for instance, using L<MooseX::FollowPBP> in the class
85 would end up renaming all of the accessors generated by the role, some of which
86 may be being called in the role, causing it to break. Roles now keep track of
87 their own attribute metaclass to use by default when being applied to a class
88 (defaulting to Moose::Meta::Attribute). This is modifiable using
89 L<Moose::Util::MetaRole> by passing the C<applied_attribute> key to the
90 C<role_metaroles> option, as in:
92 Moose::Util::MetaRole::apply_metaroles(
95 attribute => ['My::Meta::Role::Attribute'],
98 applied_attribute => ['My::Meta::Role::Attribute'],
102 =item Class::MOP has been folded into the Moose dist
104 Moose and Class::MOP are tightly related enough that they have always had to be
105 kept pretty closely in step in terms of versions. Making them into a single
106 dist should simplify the upgrade process for users, as it should no longer be
107 possible to upgrade one without the other and potentially cause issues. No
108 functionality has changed, and this should be entirely transparent.
110 =item Moose's conflict checking is more robust and useful
112 There are two parts to this. The most useful one right now is that Moose will
113 ship with a C<moose-outdated> script, which can be run at any point to list the
114 modules which are installed that conflict with the installed version of Moose.
115 After upgrading Moose, running C<moose-outdated | cpanm> should be sufficient
116 to ensure that all of the Moose extensions you use will continue to work.
118 The other part is that Moose's C<META.json> file will also specify the
119 conflicts under the C<x_conflicts> key. We are working with the Perl tool chain
120 developers to try to get conflicts support added to CPAN clients, and if/when
121 that happens, the metadata already exists, and so the conflict checking will
124 =item Most deprecated APIs/features are slated for removal in Moose 2.0200
126 Most of the deprecated APIs and features in Moose will start throwing an error
127 in Moose 2.0200. Some of the features will go away entirely, and some will
128 simply throw an error.
130 The things on the chopping block are:
134 =item * Old public methods in Class::MOP and Moose
136 This includes things like C<< Class::MOP::Class->get_attribute_map >>, C<<
137 Class::MOP::Class->construct_instance >>, and many others. These were
138 deprecated in L<Class::MOP> 0.80_01, released on April 5, 2009.
140 These methods will be removed entirely in Moose 2.0200.
142 =item * Old public functions in Class::MOP
144 This include C<Class::MOP::subname>, C<Class::MOP::in_global_destruction>, and
145 the C<Class::MOP::HAS_ISAREV> constant. The first two were deprecated in 0.84,
146 and the last in 0.80. Class::MOP 0.84 was released on May 12, 2009.
148 These functions will be removed entirely in Moose 2.0200.
150 =item * The C<alias> and C<excludes> option for role composition
152 These were renamed to C<-alias> and C<-excludes> in Moose 0.89, released on
155 Passing these will throw an error in Moose 2.0200.
157 =item * The old L<Moose::Util::MetaRole> API
159 This include the C<apply_metaclass_roles()> function, as well as passing the
160 C<for_class> or any key ending in C<_roles> to C<apply_metaroles()>. This was
161 deprecated in Moose 0.93_01, released on January 4, 2010.
163 These will all throw an error in Moose 2.0200.
165 =item * Passing plain lists to C<type()> or C<subtype()>
167 The old API for these functions allowed you to pass a plain list of parameter,
168 rather than a list of hash references (which is what C<as()>, C<where>,
169 etc. return). This was deprecated in Moose 0.71_01, released on February 22,
172 This will throw an error in Moose 2.0200.
174 =item * The Role subtype
176 This subtype was deprecated in Moose 0.84, released on June 26, 2009.
178 This will be removed entirely in Moose 2.0200.
188 =item * New release policy
190 As of the 2.0 release, Moose now has an official release and support policy,
191 documented in L<Moose::Manual::Support>. All API changes will now go through a
192 deprecation cycle of at least one year, after which the deprecated API can be
193 removed. Deprecations and removals will only happen in major releases.
195 In between major releases, we will still make minor releases to add new
196 features, fix bugs, update documentation, etc.
204 =item Configurable stacktraces
206 Classes which use the L<Moose::Error::Default> error class can now have
207 stacktraces disabled by setting the C<MOOSE_ERROR_STYLE> env var to C<croak>.
208 This is experimental, fairly incomplete, and won't work in all cases (because
209 Moose's error system in general is all of these things), but this should allow
210 for reducing at least some of the verbosity in most cases.
218 =item Native Delegations
220 In previous versions of Moose, the Native delegations were created as
221 closures. The generated code was often quite slow compared to doing the same
222 thing by hand. For example, the Array's push delegation ended up doing
225 push @{ $self->$reader() }, @_;
227 If the attribute was created without a reader, the C<$reader> sub reference
228 followed a very slow code path. Even with a reader, this is still slower than
231 Native delegations are now generated as inline code, just like other
232 accessors, so we can access the slot directly.
234 In addition, native traits now do proper constraint checking in all cases. In
235 particular, constraint checking has been improved for array and hash
236 references. Previously, only the I<contained> type (the C<Str> in
237 C<HashRef[Str]>) would be checked when a new value was added to the
238 collection. However, if there was a constraint that applied to the whole
239 value, this was never checked.
241 In addition, coercions are now called on the whole value.
243 The delegation methods now do more argument checking. All of the methods check
244 that a valid number of arguments were passed to the method. In addition, the
245 delegation methods check that the arguments are sane (array indexes, hash
246 keys, numbers, etc.) when applicable. We have tried to emulate the behavior of
247 Perl builtins as much as possible.
249 Finally, triggers are called whenever the value of the attribute is changed by
252 These changes are only likely to break code in a few cases.
254 The inlining code may or may not preserve the original reference when changes
255 are made. In some cases, methods which change the value may replace it
256 entirely. This will break tied values.
258 If you have a typed arrayref or hashref attribute where the type enforces a
259 constraint on the whole collection, this constraint will now be checked. It's
260 possible that code which previously ran without errors will now cause the
261 constraint to fail. However, presumably this is a good thing ;)
263 If you are passing invalid arguments to a delegation which were previously
264 being ignored, these calls will now fail.
266 If your code relied on the trigger only being called for a regular writer,
267 that may cause problems.
269 As always, you are encouraged to test before deploying the latest version of
272 =item Defaults is and default for String, Counter, and Bool
274 A few native traits (String, Counter, Bool) provide default values of "is" and
275 "default" when you created an attribute. Allowing them to provide these values
276 is now deprecated. Supply the value yourself when creating the attribute.
278 =item The C<meta> method
280 Moose and Class::MOP have been cleaned up internally enough to make the
281 C<meta> method that you get by default optional. C<use Moose> and
282 C<use Moose::Role> now can take an additional C<-meta_name> option, which
283 tells Moose what name to use when installing the C<meta> method. Passing
284 C<undef> to this option suppresses generation of the C<meta> method
285 entirely. This should be useful for users of modules which also use a C<meta>
286 method or function, such as L<Curses> or L<Rose::DB::Object>.
294 =item All deprecated features now warn
296 Previously, deprecation mostly consisted of simply saying "X is deprecated" in
297 the Changes file. We were not very consistent about actually warning. Now, all
298 deprecated features still present in Moose actually give a warning. The
299 warning is issued once per calling package. See L<Moose::Deprecated> for more
302 =item You cannot pass C<< coerce => 1 >> unless the attribute's type constraint has a coercion
304 Previously, this was accepted, and it sort of worked, except that if you
305 attempted to set the attribute after the object was created, you would get a
308 Now you will get a warning when you attempt to define the attribute.
310 =item C<no Moose>, C<no Moose::Role>, and C<no Moose::Exporter> no longer unimport strict and warnings
312 This change was made in 1.05, and has now been reverted. We don't know if the
313 user has explicitly loaded strict or warnings on their own, and unimporting
314 them is just broken in that case.
316 =item Reversed logic when defining which options can be changed
318 L<Moose::Meta::Attribute> now allows all options to be changed in an
319 overridden attribute. The previous behaviour required each option to be
320 whitelisted using the C<legal_options_for_inheritance> method. This method has
321 been removed, and there is a new method, C<illegal_options_for_inheritance>,
322 which can now be used to prevent certain options from being changeable.
324 In addition, we only throw an error if the illegal option is actually
325 changed. If the superclass didn't specify this option at all when defining the
326 attribute, the subclass version can still add it as an option.
328 Example of overriding this in an attribute trait:
330 package Bar::Meta::Attribute;
333 has 'my_illegal_option' => (
338 around illegal_options_for_inheritance => sub {
339 return ( shift->(@_), qw/my_illegal_option/ );
348 =item L<Moose::Object/BUILD> methods are now called when calling C<new_object>
350 Previously, C<BUILD> methods would only be called from C<Moose::Object::new>,
351 but now they are also called when constructing an object via
352 C<Moose::Meta::Class::new_object>. C<BUILD> methods are an inherent part of the
353 object construction process, and this should make C<< $meta->new_object >>
354 actually usable without forcing people to use C<< $meta->name->new >>.
356 =item C<no Moose>, C<no Moose::Role>, and C<no Moose::Exporter> now unimport strict and warnings
358 In the interest of having C<no Moose> clean up everything that C<use Moose>
359 does in the calling scope, C<no Moose> (as well as all other
360 L<Moose::Exporter>-using modules) now unimports strict and warnings.
362 =item Metaclass compatibility checking and fixing should be much more robust
364 The L<metaclass compatibility|Moose/METACLASS COMPATIBILITY AND MOOSE> checking
365 and fixing algorithms have been completely rewritten, in both Class::MOP and
366 Moose. This should resolve many confusing errors when dealing with non-Moose
367 inheritance and with custom metaclasses for things like attributes,
368 constructors, etc. For correct code, the only thing that should require a
369 change is that custom error metaclasses must now inherit from
370 L<Moose::Error::Default>.
378 =item Moose::Meta::TypeConstraint::Class is_subtype_of behavior
380 Earlier versions of L<is_subtype_of|Moose::Meta::TypeConstraint::Class/is_subtype_of>
381 would incorrectly return true when called with itself, its own TC name or
382 its class name as an argument. (i.e. $foo_tc->is_subtype_of('Foo') == 1) This
383 behavior was a caused by C<isa> being checked before the class name. The old
384 behavior can be accessed with L<is_type_of|Moose::Meta::TypeConstraint::Class/is_type_of>
392 =item Moose::Meta::Attribute::Native::Trait::Code no longer creates reader methods by default
394 Earlier versions of L<Moose::Meta::Attribute::Native::Trait::Code> created
395 read-only accessors for the attributes it's been applied to, even if you didn't
396 ask for it with C<< is => 'ro' >>. This incorrect behaviour has now been fixed.
404 =item Moose::Util add_method_modifier behavior
406 add_method_modifier (and subsequently the sugar functions Moose::before,
407 Moose::after, and Moose::around) can now accept arrayrefs, with the same
408 behavior as lists. Types other than arrayref and regexp result in an error.
412 =head1 0.93_01 and 0.94
416 =item Moose::Util::MetaRole API has changed
418 The C<apply_metaclass_roles> function is now called C<apply_metaroles>. The
419 way arguments are supplied has been changed to force you to distinguish
420 between metaroles applied to L<Moose::Meta::Class> (and helpers) versus
421 L<Moose::Meta::Role>.
423 The old API still works, but will warn in a future release, and eventually be
426 =item Moose::Meta::Role has real attributes
428 The attributes returned by L<Moose::Meta::Role> are now instances of the
429 L<Moose::Meta::Role::Attribute> class, instead of bare hash references.
431 =item "no Moose" now removes C<blessed> and C<confess>
433 Moose is now smart enough to know exactly what it exported, even when it
434 re-exports functions from other packages. When you unimport Moose, it will
435 remove these functions from your namespace unless you I<also> imported them
436 directly from their respective packages.
438 If you have a C<no Moose> in your code I<before> you call C<blessed> or
439 C<confess>, your code will break. You can either move the C<no Moose> call
440 later in your code, or explicitly import the relevant functions from the
441 packages that provide them.
443 =item L<Moose::Exporter> is smarter about unimporting re-exports
445 The change above comes from a general improvement to L<Moose::Exporter>. It
446 will now unimport any function it exports, even if that function is a
447 re-export from another package.
449 =item Attributes in roles can no longer override class attributes with "+foo"
451 Previously, this worked more or less accidentally, because role attributes
452 weren't objects. This was never documented, but a few MooseX modules took
455 =item The composition_class_roles attribute in L<Moose::Meta::Role> is now a method
457 This was done to make it possible for roles to alter the the list of
458 composition class roles by applying a method modifiers. Previously, this was
459 an attribute and MooseX modules override it. Since that no longer works, this
462 This I<should> be an attribute, so this may switch back to being an attribute
463 in the future if we can figure out how to make this work.
471 =item Calling $object->new() is no longer deprecated
473 We decided to undeprecate this. Now it just works.
475 =item Both C<get_method_map> and C<get_attribute_map> is deprecated
477 These metaclass methods were never meant to be public, and they are both now
478 deprecated. The work around if you still need the functionality they provided
479 is to iterate over the list of names manually.
481 my %fields = map { $_ => $meta->get_attribute($_) } $meta->get_attribute_list;
483 This was actually a change in L<Class::MOP>, but this version of Moose
484 requires a version of L<Class::MOP> that includes said change.
492 =item Added Native delegation for Code refs
494 See L<Moose::Meta::Attribute::Native::Trait::Code> for details.
496 =item Calling $object->new() is deprecated
498 Moose has long supported this, but it's never really been documented, and we
499 don't think this is a good practice. If you want to construct an object from
500 an existing object, you should provide some sort of alternate constructor like
501 C<< $object->clone >>.
503 Calling C<< $object->new >> now issues a warning, and will be an error in a
506 =item Moose no longer warns if you call C<make_immutable> for a class with mutable ancestors
508 While in theory this is a good thing to warn about, we found so many
509 exceptions to this that doing this properly became quite problematic.
517 =item New Native delegation methods from L<List::Util> and L<List::MoreUtils>
519 In particular, we now have C<reduce>, C<shuffle>, C<uniq>, and C<natatime>.
521 =item The Moose::Exporter with_caller feature is now deprecated
523 Use C<with_meta> instead. The C<with_caller> option will start warning in a
526 =item Moose now warns if you call C<make_immutable> for a class with mutable ancestors
528 This is dangerous because modifying a class after a subclass has been
529 immutabilized will lead to incorrect results in the subclass, due to inlining,
530 caching, etc. This occasionally happens accidentally, when a class loads one
531 of its subclasses in the middle of its class definition, so pointing out that
532 this may cause issues should be helpful. Metaclasses (classes that inherit
533 from L<Class::MOP::Object>) are currently exempt from this check, since at the
534 moment we aren't very consistent about which metaclasses we immutabilize.
536 =item C<enum> and C<duck_type> now take arrayrefs for all forms
538 Previously, calling these functions with a list would take the first element of
539 the list as the type constraint name, and use the remainder as the enum values
540 or method names. This makes the interface inconsistent with the anon-type forms
541 of these functions (which must take an arrayref), and a free-form list where
542 the first value is sometimes special is hard to validate (and harder to give
543 reasonable error messages for). These functions have been changed to take
544 arrayrefs in all their forms - so, C<< enum 'My::Type' => [qw(foo bar)] >> is
545 now the preferred way to create an enum type constraint. The old syntax still
546 works for now, but it will hopefully be deprecated and removed in a future
553 L<Moose::Meta::Attribute::Native> has been moved into the Moose core from
554 L<MooseX::AttributeHelpers>. Major changes include:
558 =item C<traits>, not C<metaclass>
560 Method providers are only available via traits.
562 =item C<handles>, not C<provides> or C<curries>
564 The C<provides> syntax was like core Moose C<< handles => HASHREF >>
565 syntax, but with the keys and values reversed. This was confusing,
566 and AttributeHelpers now uses C<< handles => HASHREF >> in a way that
567 should be intuitive to anyone already familiar with how it is used for
570 The C<curries> functionality provided by AttributeHelpers has been
571 generalized to apply to all cases of C<< handles => HASHREF >>, though
572 not every piece of functionality has been ported (currying with a
573 CODEREF is not supported).
575 =item C<empty> is now C<is_empty>, and means empty, not non-empty
577 Previously, the C<empty> method provided by Arrays and Hashes returned true if
578 the attribute was B<not> empty (no elements). Now it returns true if the
579 attribute B<is> empty. It was also renamed to C<is_empty>, to reflect this.
581 =item C<find> was renamed to C<first>, and C<first> and C<last> were removed
583 L<List::Util> refers to the functionality that we used to provide under C<find>
584 as L<first|List::Util/first>, so that will likely be more familiar (and will
585 fit in better if we decide to add more List::Util functions). C<first> and
586 C<last> were removed, since their functionality is easily duplicated with
589 =item Helpers that take a coderef of one argument now use C<$_>
591 Subroutines passed as the first argument to C<first>, C<map>, and C<grep> now
592 receive their argument in C<$_> rather than as a parameter to the subroutine.
593 Helpers that take a coderef of two or more arguments remain using the argument
594 list (there are technical limitations to using C<$a> and C<$b> like C<sort>
597 See L<Moose::Meta::Attribute::Native> for the new documentation.
601 The C<alias> and C<excludes> role parameters have been renamed to C<-alias>
602 and C<-excludes>. The old names still work, but new code should use the new
603 names, and eventually the old ones will be deprecated and removed.
607 C<< use Moose -metaclass => 'Foo' >> now does alias resolution, just like
608 C<-traits> (and the C<metaclass> and C<traits> options to C<has>).
610 Added two functions C<meta_class_alias> and C<meta_attribute_alias> to
611 L<Moose::Util>, to simplify aliasing metaclasses and metatraits. This is
612 a wrapper around the old
614 package Moose::Meta::Class::Custom::Trait::FooTrait;
615 sub register_implementation { 'My::Meta::Trait' }
621 When an attribute generates I<no> accessors, we now warn. This is to help
622 users who forget the C<is> option. If you really do not want any accessors,
623 you can use C<< is => 'bare' >>. You can maintain back compat with older
624 versions of Moose by using something like:
626 ($Moose::VERSION >= 0.84 ? is => 'bare' : ())
628 When an accessor overwrites an existing method, we now warn. To work around
629 this warning (if you really must have this behavior), you can explicitly
630 remove the method before creating it as an accessor:
634 __PACKAGE__->meta->remove_method('foo');
640 When an unknown option is passed to C<has>, we now warn. You can silence
641 the warning by fixing your code. :)
643 The C<Role> type has been deprecated. On its own, it was useless,
644 since it just checked C<< $object->can('does') >>. If you were using
645 it as a parent type, just call C<role_type('Role::Name')> to create an
646 appropriate type instead.
650 C<use Moose::Exporter;> now imports C<strict> and C<warnings> into packages
655 C<DEMOLISHALL> and C<DEMOLISH> now receive an argument indicating whether or
656 not we are in global destruction.
660 Type constraints no longer run coercions for a value that already matches the
661 constraint. This may affect some (arguably buggy) edge case coercions that
662 rely on side effects in the C<via> clause.
666 L<Moose::Exporter> now accepts the C<-metaclass> option for easily
667 overriding the metaclass (without L<metaclass>). This works for classes
672 Added a C<duck_type> sugar function to L<Moose::Util::TypeConstraints>
673 to make integration with non-Moose classes easier. It simply checks if
674 C<< $obj->can() >> a list of methods.
676 A number of methods (mostly inherited from L<Class::MOP>) have been
677 renamed with a leading underscore to indicate their internal-ness. The
678 old method names will still work for a while, but will warn that the
679 method has been renamed. In a few cases, the method will be removed
680 entirely in the future. This may affect MooseX authors who were using
685 Calling C<subtype> with a name as the only argument now throws an
686 exception. If you want an anonymous subtype do:
688 my $subtype = subtype as 'Foo';
690 This is related to the changes in version 0.71_01.
692 The C<is_needed> method in L<Moose::Meta::Method::Destructor> is now
693 only usable as a class method. Previously, it worked as a class or
694 object method, with a different internal implementation for each
697 The internals of making a class immutable changed a lot in Class::MOP
698 0.78_02, and Moose's internals have changed along with it. The
699 external C<< $metaclass->make_immutable >> method still works the same
704 A mutable class accepted C<< Foo->new(undef) >> without complaint,
705 while an immutable class would blow up with an unhelpful error. Now,
706 in both cases we throw a helpful error instead.
708 This "feature" was originally added to allow for cases such as this:
716 return My::Class->new($args);
718 But we decided this is a bad idea and a little too magical, because it
719 can easily mask real errors.
723 Calling C<type> or C<subtype> without the sugar helpers (C<as>,
724 C<where>, C<message>) is now deprecated.
726 As a side effect, this meant we ended up using Perl prototypes on
727 C<as>, and code like this will no longer work:
729 use Moose::Util::TypeConstraints;
730 use Declare::Constraints::Simple -All;
732 subtype 'ArrayOfInts'
734 => IsArrayRef(IsInt);
736 Instead it must be changed to this:
741 where => IsArrayRef(IsInt)
745 If you want to maintain backwards compat with older versions of Moose,
746 you must explicitly test Moose's C<VERSION>:
748 if ( Moose->VERSION < 0.71_01 ) {
749 subtype 'ArrayOfInts'
751 => IsArrayRef(IsInt);
757 where => IsArrayRef(IsInt)
764 We no longer pass the meta-attribute object as a final argument to
765 triggers. This actually changed for inlined code a while back, but the
766 non-inlined version and the docs were still out of date.
768 If by some chance you actually used this feature, the workaround is
769 simple. You fetch the attribute object from out of the C<$self>
770 that is passed as the first argument to trigger, like so:
776 my ( $self, $value ) = @_;
777 my $attr = $self->meta->find_attribute_by_name('foo');
785 If you created a subtype and passed a parent that Moose didn't know
786 about, it simply ignored the parent. Now it automatically creates the
787 parent as a class type. This may not be what you want, but is less
790 You could declare a name with subtype such as "Foo!Bar". Moose would
791 accept this allowed, but if you used it in a parameterized type such
792 as "ArrayRef[Foo!Bar]" it wouldn't work. We now do some vetting on
793 names created via the sugar functions, so that they can only contain
794 alphanumerics, ":", and ".".
798 Methods created via an attribute can now fulfill a C<requires>
799 declaration for a role. Honestly we don't know why Stevan didn't make
800 this work originally, he was just insane or something.
802 Stack traces from inlined code will now report the line and file as
803 being in your class, as opposed to in Moose guts.
807 When a class does not provide all of a role's required methods, the
808 error thrown now mentions all of the missing methods, as opposed to
809 just the first missing method.
811 Moose will no longer inline a constructor for your class unless it
812 inherits its constructor from Moose::Object, and will warn when it
813 doesn't inline. If you want to force inlining anyway, pass
814 C<< replace_constructor => 1 >> to C<make_immutable>.
816 If you want to get rid of the warning, pass C<< inline_constructor =>
821 Removed the (deprecated) C<make_immutable> keyword.
823 Removing an attribute from a class now also removes delegation
824 (C<handles>) methods installed for that attribute. This is correct
825 behavior, but if you were wrongly relying on it you might get bit.
829 Roles now add methods by calling C<add_method>, not
830 C<alias_method>. They make sure to always provide a method object,
831 which will be cloned internally. This means that it is now possible to
832 track the source of a method provided by a role, and even follow its
833 history through intermediate roles. This means that methods added by
834 a role now show up when looking at a class's method list/map.
836 Parameter and Union args are now sorted, this makes Int|Str the same
837 constraint as Str|Int. Also, incoming type constraint strings are
838 normalized to remove all whitespace differences. This is mostly for
839 internals and should not affect outside code.
841 L<Moose::Exporter> will no longer remove a subroutine that the
842 exporting package re-exports. Moose re-exports the Carp::confess
843 function, among others. The reasoning is that we cannot know whether
844 you have also explicitly imported those functions for your own use, so
845 we err on the safe side and always keep them.
849 C<Moose::init_meta> should now be called as a method.
851 New modules for extension writers, L<Moose::Exporter> and
852 L<Moose::Util::MetaRole>.
856 Implemented metaclass traits (and wrote a recipe for it):
858 use Moose -traits => 'Foo'
860 This should make writing small Moose extensions a little
865 Fixed C<coerce> to accept anon types just like C<subtype> can.
868 coerce $some_anon_type => from 'Str' => via { ... };
872 Added C<BUILDARGS>, a new step in C<< Moose::Object->new() >>.
876 Fixed how the C<< is => (ro|rw) >> works with custom defined
877 C<reader>, C<writer> and C<accessor> options. See the below table for
880 is => ro, writer => _foo # turns into (reader => foo, writer => _foo)
881 is => rw, writer => _foo # turns into (reader => foo, writer => _foo)
882 is => rw, accessor => _foo # turns into (accessor => _foo)
883 is => ro, accessor => _foo # error, accesor is rw
887 The C<before/around/after> method modifiers now support regexp
888 matching of method names. NOTE: this only works for classes, it is
889 currently not supported in roles, but, ... patches welcome.
891 The C<has> keyword for roles now accepts the same array ref form that
892 L<Moose>.pm does for classes.
894 A trigger on a read-only attribute is no longer an error, as it's
895 useful to trigger off of the constructor.
897 Subtypes of parameterizable types now are parameterizable types
902 Fixed issue where C<DEMOLISHALL> was eating the value in C<$@>, and so
903 not working correctly. It still kind of eats them, but so does vanilla
908 Inherited attributes may now be extended without restriction on the
909 type ('isa', 'does').
911 The entire set of Moose::Meta::TypeConstraint::* classes were
912 refactored in this release. If you were relying on their internals you
913 should test your code carefully.
917 Documenting the use of '+name' with attributes that come from recently
918 composed roles. It makes sense, people are using it, and so why not
919 just officially support it.
921 The C<< Moose::Meta::Class->create >> method now supports roles.
923 It is now possible to make anonymous enum types by passing C<enum> an
924 array reference instead of the C<< enum $name => @values >>.
928 Added the C<make_immutable> keyword as a shortcut to calling
929 C<make_immutable> on the meta object. This eventually got removed!
931 Made C<< init_arg => undef >> work in Moose. This means "do not accept
932 a constructor parameter for this attribute".
934 Type errors now use the provided message. Prior to this release they
939 Moose is now a postmodern object system :)
941 The Role system was completely refactored. It is 100% backwards
942 compat, but the internals were totally changed. If you relied on the
943 internals then you are advised to test carefully.
945 Added method exclusion and aliasing for Roles in this release.
947 Added the L<Moose::Util::TypeConstraints::OptimizedConstraints>
950 Passing a list of values to an accessor (which is only expecting one
951 value) used to be silently ignored, now it throws an error.
955 Added parameterized types and did a pretty heavy refactoring of the
956 type constraint system.
958 Better framework extensibility and better support for "making your own
961 =head1 0.25 or before
963 Honestly, you shouldn't be using versions of Moose that are this old,
964 so many bug fixes and speed improvements have been made you would be
965 crazy to not upgrade.
967 Also, I am tired of going through the Changelog so I am stopping here,
968 if anyone would like to continue this please feel free.