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 backwards. This does duplicate data from the F<Changes> file,
13 but aims to provide more details and when possible workarounds.
15 Besides helping keep up with changes, you can also use this document
16 for finding the lowest version of Moose that supported a given
17 feature. If you encounter a problem and have a solution but don't see
18 it documented here, or think we missed an important feature, please
25 =item More useful type constraint error messages
27 If you have L<Devel::PartialDump> version 0.14 or higher installed, Moose's
28 type constraint error messages will use it to display the invalid value, rather
29 than just displaying it directly. This will generally be much more useful. For
30 instance, instead of this:
32 Attribute (foo) does not pass the type constraint because: Validation failed for 'ArrayRef[Int]' with value ARRAY(0x275eed8)
34 the error message will instead look like
36 Attribute (foo) does not pass the type constraint because: Validation failed for 'ArrayRef[Int]' with value [ "a" ]
38 Note that L<Devel::PartialDump> can't be made a direct dependency at the
39 moment, because it uses Moose itself, but we're considering options to make
48 =item Roles have their own default attribute metaclass
50 Previously, when a role was applied to a class, it would use the attribute
51 metaclass defined in the class when copying over the attributes in the role.
52 This was wrong, because for instance, using L<MooseX::FollowPBP> in the class
53 would end up renaming all of the accessors generated by the role, some of which
54 may be being called in the role, causing it to break. Roles now keep track of
55 their own attribute metaclass to use by default when being applied to a class
56 (defaulting to Moose::Meta::Attribute). This is modifiable using
57 L<Moose::Util::MetaRole> by passing the C<applied_attribute> key to the
58 C<role_metaroles> option, as in:
60 Moose::Util::MetaRole::apply_metaroles(
63 attribute => ['My::Meta::Role::Attribute'],
66 applied_attribute => ['My::Meta::Role::Attribute'],
70 =item Class::MOP has been folded into the Moose dist
72 Moose and Class::MOP are tightly related enough that they have always had to be
73 kept pretty closely in step in terms of versions. Making them into a single
74 dist should simplify the upgrade process for users, as it should no longer be
75 possible to upgrade one without the other and potentially cause issues. No
76 functionality has changed, and this should be entirely transparent.
78 =item Moose's conflict checking is more robust and useful
80 There are two parts to this. The most useful one right now is that Moose will
81 ship with a C<moose-outdated> script, which can be run at any point to list the
82 modules which are installed that conflict with the installed version of Moose.
83 After upgrading Moose, running C<moose-outdated | cpanm> should be sufficient
84 to ensure that all of the Moose extensions you use will continue to work.
86 The other part is that Moose's C<META.json> file will also specify the
87 conflicts under the C<x_conflicts> key. We are working with the Perl tool chain
88 developers to try to get conflicts support added to CPAN clients, and if/when
89 that happens, the metadata already exists, and so the conflict checking will
92 =item Most deprecated APIs/features are slated for removal in Moose 2.0200
94 Most of the deprecated APIs and features in Moose will start throwing an error
95 in Moose 2.0200. Some of the features will go away entirely, and some will
96 simply throw an error.
98 The things on the chopping block are:
102 =item * Old public methods in Class::MOP and Moose
104 This includes things like C<< Class::MOP::Class->get_attribute_map >>, C<<
105 Class::MOP::Class->construct_instance >>, and many others. These were
106 deprecated in L<Class::MOP> 0.80_01, release on April 5, 2009.
108 These methods will be removed entirely in Moose 2.0200.
110 =item * Old public functions in Class::MOP
112 This include C<Class::MOP::subname>, C<Class::MOP::in_global_destruction>, and
113 the C<Class::MOP::HAS_ISAREV> constant. The first two were deprecated in 0.84,
114 and the last in 0.80. Class::MOP 0.84 was released on May 12, 2009.
116 These functions will be removed entirely in Moose 2.0200.
118 =item * The C<alias> and C<excludes> option for role composition
120 These were renamed to C<-alias> and C<-excludes> in Moose 0.89, released on
123 Passing these will throw an error in Moose 2.0200.
125 =item * The old L<Moose::Util::MetaRole> API
127 This include the C<apply_metaclass_roles()> function, as well as passing the
128 C<for_class> or any key ending in C<_roles> to C<apply_metaroles()>. This was
129 deprecated in Moose 0.93_01, released on January 4, 2010.
131 These will all throw an error in Moose 2.0200.
133 =item * Passing plain lists to C<type()> or C<subtype()>
135 The old API for these functions allowed you to pass a plain list of parameter,
136 rather than a list of hash references (which is what C<as()>, C<where>,
137 etc. return). This was deprecated in Moose 0.71_01, released on February 22,
140 This will throw an error in Moose 2.0200.
142 =item * The Role subtype
144 This subtype was deprecated in Moose 0.84, released on June 26, 2009.
146 This will be removed entirely in Moose 2.0200.
156 =item * New release policy
158 As of the 2.0 release, Moose now has an official release and support policy,
159 documented in L<Moose::Manual::Support>. All API changes will now go through a
160 deprecation cycle of at least one year, after which the deprecated API can be
161 removed. Deprecations and removals will only happen in major releases.
163 In between major release, we will still make minor releases to add new
164 features, fix bugs, update documentation, etc.
172 =item Configurable stacktraces
174 Classes which use the L<Moose::Error::Default> error class can now have
175 stacktraces disabled by setting the C<MOOSE_ERROR_STYLE> env var to C<croak>.
176 This is experimental, fairly incomplete, and won't work in all cases (because
177 Moose's error system in general is all of these things), but this should allow
178 for reducing at least some of the verbosity in most cases.
186 =item Native Delegations
188 In previous versions of Moose, the Native delegations were created as
189 closures. The generated code was often quite slow compared to doing the same
190 thing by hand. For example, the Array's push delegation ended up doing
193 push @{ $self->$reader() }, @_;
195 If the attribute was created without a reader, the C<$reader> sub reference
196 followed a very slow code path. Even with a reader, this is still slower than
199 Native delegations are now generated as inline code, just like other
200 accessors, so we can access the slot directly.
202 In addition, native traits now do proper constraint checking in all cases. In
203 particular, constraint checking has been improved for array and hash
204 references. Previously, only the I<contained> type (the C<Str> in
205 C<HashRef[Str]>) would be checked when a new value was added to the
206 collection. However, if there was a constraint that applied to the whole
207 value, this was never checked.
209 In addition, coercions are now called on the whole value.
211 The delegation methods now do more argument checking. All of the methods check
212 that a valid number of arguments were passed to the method. In addition, the
213 delegation methods check that the arguments are sane (array indexes, hash
214 keys, numbers, etc.) when applicable. We have tried to emulate the behavior of
215 Perl builtins as much as possible.
217 Finally, triggers are called whenever the value of the attribute is changed by
220 These changes are only likely to break code in a few cases.
222 The inlining code may or may not preserve the original reference when changes
223 are made. In some cases, methods which change the value may replace it
224 entirely. This will break tied values.
226 If you have a typed arrayref or hashref attribute where the type enforces a
227 constraint on the whole collection, this constraint will now be checked. It's
228 possible that code which previously ran without errors will now cause the
229 constraint to fail. However, presumably this is a good thing ;)
231 If you are passing invalid arguments to a delegation which were previously
232 being ignored, these calls will now fail.
234 If your code relied on the trigger only being called for a regular writer,
235 that may cause problems.
237 As always, you are encouraged to test before deploying the latest version of
240 =item Defaults is and default for String, Counter, and Bool
242 A few native traits (String, Counter, Bool) provide default values of "is" and
243 "default" when you created an attribute. Allowing them to provide these values
244 is now deprecated. Supply the value yourself when creating the attribute.
246 =item The C<meta> method
248 Moose and Class::MOP have been cleaned up internally enough to make the
249 C<meta> method that you get by default optional. C<use Moose> and
250 C<use Moose::Role> now can take an additional C<-meta_name> option, which
251 tells Moose what name to use when installing the C<meta> method. Passing
252 C<undef> to this option suppresses generation of the C<meta> method
253 entirely. This should be useful for users of modules which also use a C<meta>
254 method or function, such as L<Curses> or L<Rose::DB::Object>.
262 =item All deprecated features now warn
264 Previously, deprecation mostly consisted of simply saying "X is deprecated" in
265 the Changes file. We were not very consistent about actually warning. Now, all
266 deprecated features still present in Moose actually give a warning. The
267 warning is issued once per calling package. See L<Moose::Deprecated> for more
270 =item You cannot pass C<< coerce => 1 >> unless the attribute's type constraint has a coercion
272 Previously, this was accepted, and it sort of worked, except that if you
273 attempted to set the attribute after the object was created, you would get a
276 Now you will get a warning when you attempt to define the attribute.
278 =item C<no Moose>, C<no Moose::Role>, and C<no Moose::Exporter> no longer unimport strict and warnings
280 This change was made in 1.05, and has now been reverted. We don't know if the
281 user has explicitly loaded strict or warnings on their own, and unimporting
282 them is just broken in that case.
284 =item Reversed logic when defining which options can be changed
286 L<Moose::Meta::Attribute> now allows all options to be changed in an
287 overridden attribute. The previous behaviour required each option to be
288 whitelisted using the C<legal_options_for_inheritance> method. This method has
289 been removed, and there is a new method, C<illegal_options_for_inheritance>,
290 which can now be used to prevent certain options from being changeable.
292 In addition, we only throw an error if the illegal option is actually
293 changed. If the superclass didn't specify this option at all when defining the
294 attribute, the subclass version can still add it as an option.
296 Example of overriding this in an attribute trait:
298 package Bar::Meta::Attribute;
301 has 'my_illegal_option' => (
306 around illegal_options_for_inheritance => sub {
307 return ( shift->(@_), qw/my_illegal_option/ );
316 =item L<Moose::Object/BUILD> methods are now called when calling C<new_object>
318 Previously, C<BUILD> methods would only be called from C<Moose::Object::new>,
319 but now they are also called when constructing an object via
320 C<Moose::Meta::Class::new_object>. C<BUILD> methods are an inherent part of the
321 object construction process, and this should make C<< $meta->new_object >>
322 actually usable without forcing people to use C<< $meta->name->new >>.
324 =item C<no Moose>, C<no Moose::Role>, and C<no Moose::Exporter> now unimport strict and warnings
326 In the interest of having C<no Moose> clean up everything that C<use Moose>
327 does in the calling scope, C<no Moose> (as well as all other
328 L<Moose::Exporter>-using modules) now unimports strict and warnings.
330 =item Metaclass compatibility checking and fixing should be much more robust
332 The L<metaclass compatibility|Moose/METACLASS COMPATIBILITY AND MOOSE> checking
333 and fixing algorithms have been completely rewritten, in both Class::MOP and
334 Moose. This should resolve many confusing errors when dealing with non-Moose
335 inheritance and with custom metaclasses for things like attributes,
336 constructors, etc. For correct code, the only thing that should require a
337 change is that custom error metaclasses must now inherit from
338 L<Moose::Error::Default>.
346 =item Moose::Meta::TypeConstraint::Class is_subtype_of behavior
348 Earlier versions of L<is_subtype_of|Moose::Meta::TypeConstraint::Class/is_subtype_of>
349 would incorrectly return true when called with itself, its own TC name or
350 its class name as an argument. (i.e. $foo_tc->is_subtype_of('Foo') == 1) This
351 behavior was a caused by C<isa> being checked before the class name. The old
352 behavior can be accessed with L<is_type_of|Moose::Meta::TypeConstraint::Class/is_type_of>
360 =item Moose::Meta::Attribute::Native::Trait::Code no longer creates reader methods by default
362 Earlier versions of L<Moose::Meta::Attribute::Native::Trait::Code> created
363 read-only accessors for the attributes it's been applied to, even if you didn't
364 ask for it with C<< is => 'ro' >>. This incorrect behaviour has now been fixed.
372 =item Moose::Util add_method_modifier behavior
374 add_method_modifier (and subsequently the sugar functions Moose::before,
375 Moose::after, and Moose::around) can now accept arrayrefs, with the same
376 behavior as lists. Types other than arrayref and regexp result in an error.
380 =head1 0.93_01 and 0.94
384 =item Moose::Util::MetaRole API has changed
386 The C<apply_metaclass_roles> function is now called C<apply_metaroles>. The
387 way arguments are supplied has been changed to force you to distinguish
388 between metaroles applied to L<Moose::Meta::Class> (and helpers) versus
389 L<Moose::Meta::Role>.
391 The old API still works, but will warn in a future release, and eventually be
394 =item Moose::Meta::Role has real attributes
396 The attributes returned by L<Moose::Meta::Role> are now instances of the
397 L<Moose::Meta::Role::Attribute> class, instead of bare hash references.
399 =item "no Moose" now removes C<blessed> and C<confess>
401 Moose is now smart enough to know exactly what it exported, even when it
402 re-exports functions from other packages. When you unimport Moose, it will
403 remove these functions from your namespace unless you I<also> imported them
404 directly from their respective packages.
406 If you have a C<no Moose> in your code I<before> you call C<blessed> or
407 C<confess>, your code will break. You can either move the C<no Moose> call
408 later in your code, or explicitly import the relevant functions from the
409 packages that provide them.
411 =item L<Moose::Exporter> is smarter about unimporting re-exports
413 The change above comes from a general improvement to L<Moose::Exporter>. It
414 will now unimport any function it exports, even if that function is a
415 re-export from another package.
417 =item Attributes in roles can no longer override class attributes with "+foo"
419 Previously, this worked more or less accidentally, because role attributes
420 weren't objects. This was never documented, but a few MooseX modules took
423 =item The composition_class_roles attribute in L<Moose::Meta::Role> is now a method
425 This was done to make it possible for roles to alter the the list of
426 composition class roles by applying a method modifiers. Previously, this was
427 an attribute and MooseX modules override it. Since that no longer works, this
430 This I<should> be an attribute, so this may switch back to being an attribute
431 in the future if we can figure out how to make this work.
439 =item Calling $object->new() is no longer deprecated
441 We decided to undeprecate this. Now it just works.
443 =item Both C<get_method_map> and C<get_attribute_map> is deprecated
445 These metaclass methods were never meant to be public, and they are both now
446 deprecated. The work around if you still need the functionality they provided
447 is to iterate over the list of names manually.
449 my %fields = map { $_ => $meta->get_attribute($_) } $meta->get_attribute_list;
451 This was actually a change in L<Class::MOP>, but this version of Moose
452 requires a version of L<Class::MOP> that includes said change.
460 =item Added Native delegation for Code refs
462 See L<Moose::Meta::Attribute::Native::Trait::Code> for details.
464 =item Calling $object->new() is deprecated
466 Moose has long supported this, but it's never really been documented, and we
467 don't think this is a good practice. If you want to construct an object from
468 an existing object, you should provide some sort of alternate constructor like
469 C<< $object->clone >>.
471 Calling C<< $object->new >> now issues a warning, and will be an error in a
474 =item Moose no longer warns if you call C<make_immutable> for a class with mutable ancestors
476 While in theory this is a good thing to warn about, we found so many
477 exceptions to this that doing this properly became quite problematic.
485 =item New Native delegation methods from L<List::Util> and L<List::MoreUtils>
487 In particular, we now have C<reduce>, C<shuffle>, C<uniq>, and C<natatime>.
489 =item The Moose::Exporter with_caller feature is now deprecated
491 Use C<with_meta> instead. The C<with_caller> option will start warning in a
494 =item Moose now warns if you call C<make_immutable> for a class with mutable ancestors
496 This is dangerous because modifying a class after a subclass has been
497 immutabilized will lead to incorrect results in the subclass, due to inlining,
498 caching, etc. This occasionally happens accidentally, when a class loads one
499 of its subclasses in the middle of its class definition, so pointing out that
500 this may cause issues should be helpful. Metaclasses (classes that inherit
501 from L<Class::MOP::Object>) are currently exempt from this check, since at the
502 moment we aren't very consistent about which metaclasses we immutabilize.
504 =item C<enum> and C<duck_type> now take arrayrefs for all forms
506 Previously, calling these functions with a list would take the first element of
507 the list as the type constraint name, and use the remainder as the enum values
508 or method names. This makes the interface inconsistent with the anon-type forms
509 of these functions (which must take an arrayref), and a free-form list where
510 the first value is sometimes special is hard to validate (and harder to give
511 reasonable error messages for). These functions have been changed to take
512 arrayrefs in all their forms - so, C<< enum 'My::Type' => [qw(foo bar)] >> is
513 now the preferred way to create an enum type constraint. The old syntax still
514 works for now, but it will hopefully be deprecated and removed in a future
521 L<Moose::Meta::Attribute::Native> has been moved into the Moose core from
522 L<MooseX::AttributeHelpers>. Major changes include:
526 =item C<traits>, not C<metaclass>
528 Method providers are only available via traits.
530 =item C<handles>, not C<provides> or C<curries>
532 The C<provides> syntax was like core Moose C<< handles => HASHREF >>
533 syntax, but with the keys and values reversed. This was confusing,
534 and AttributeHelpers now uses C<< handles => HASHREF >> in a way that
535 should be intuitive to anyone already familiar with how it is used for
538 The C<curries> functionality provided by AttributeHelpers has been
539 generalized to apply to all cases of C<< handles => HASHREF >>, though
540 not every piece of functionality has been ported (currying with a
541 CODEREF is not supported).
543 =item C<empty> is now C<is_empty>, and means empty, not non-empty
545 Previously, the C<empty> method provided by Arrays and Hashes returned true if
546 the attribute was B<not> empty (no elements). Now it returns true if the
547 attribute B<is> empty. It was also renamed to C<is_empty>, to reflect this.
549 =item C<find> was renamed to C<first>, and C<first> and C<last> were removed
551 L<List::Util> refers to the functionality that we used to provide under C<find>
552 as L<first|List::Util/first>, so that will likely be more familiar (and will
553 fit in better if we decide to add more List::Util functions). C<first> and
554 C<last> were removed, since their functionality is easily duplicated with
557 =item Helpers that take a coderef of one argument now use C<$_>
559 Subroutines passed as the first argument to C<first>, C<map>, and C<grep> now
560 receive their argument in C<$_> rather than as a parameter to the subroutine.
561 Helpers that take a coderef of two or more arguments remain using the argument
562 list (there are technical limitations to using C<$a> and C<$b> like C<sort>
565 See L<Moose::Meta::Attribute::Native> for the new documentation.
569 The C<alias> and C<excludes> role parameters have been renamed to C<-alias>
570 and C<-excludes>. The old names still work, but new code should use the new
571 names, and eventually the old ones will be deprecated and removed.
575 C<< use Moose -metaclass => 'Foo' >> now does alias resolution, just like
576 C<-traits> (and the C<metaclass> and C<traits> options to C<has>).
578 Added two functions C<meta_class_alias> and C<meta_attribute_alias> to
579 L<Moose::Util>, to simplify aliasing metaclasses and metatraits. This is
580 a wrapper around the old
582 package Moose::Meta::Class::Custom::Trait::FooTrait;
583 sub register_implementation { 'My::Meta::Trait' }
589 When an attribute generates I<no> accessors, we now warn. This is to help
590 users who forget the C<is> option. If you really do not want any accessors,
591 you can use C<< is => 'bare' >>. You can maintain back compat with older
592 versions of Moose by using something like:
594 ($Moose::VERSION >= 0.84 ? is => 'bare' : ())
596 When an accessor overwrites an existing method, we now warn. To work around
597 this warning (if you really must have this behavior), you can explicitly
598 remove the method before creating it as an accessor:
602 __PACKAGE__->meta->remove_method('foo');
608 When an unknown option is passed to C<has>, we now warn. You can silence
609 the warning by fixing your code. :)
611 The C<Role> type has been deprecated. On its own, it was useless,
612 since it just checked C<< $object->can('does') >>. If you were using
613 it as a parent type, just call C<role_type('Role::Name')> to create an
614 appropriate type instead.
618 C<use Moose::Exporter;> now imports C<strict> and C<warnings> into packages
623 C<DEMOLISHALL> and C<DEMOLISH> now receive an argument indicating whether or
624 not we are in global destruction.
628 Type constraints no longer run coercions for a value that already matches the
629 constraint. This may affect some (arguably buggy) edge case coercions that
630 rely on side effects in the C<via> clause.
634 L<Moose::Exporter> now accepts the C<-metaclass> option for easily
635 overriding the metaclass (without L<metaclass>). This works for classes
640 Added a C<duck_type> sugar function to L<Moose::Util::TypeConstraints>
641 to make integration with non-Moose classes easier. It simply checks if
642 C<< $obj->can() >> a list of methods.
644 A number of methods (mostly inherited from L<Class::MOP>) have been
645 renamed with a leading underscore to indicate their internal-ness. The
646 old method names will still work for a while, but will warn that the
647 method has been renamed. In a few cases, the method will be removed
648 entirely in the future. This may affect MooseX authors who were using
653 Calling C<subtype> with a name as the only argument now throws an
654 exception. If you want an anonymous subtype do:
656 my $subtype = subtype as 'Foo';
658 This is related to the changes in version 0.71_01.
660 The C<is_needed> method in L<Moose::Meta::Method::Destructor> is now
661 only usable as a class method. Previously, it worked as a class or
662 object method, with a different internal implementation for each
665 The internals of making a class immutable changed a lot in Class::MOP
666 0.78_02, and Moose's internals have changed along with it. The
667 external C<< $metaclass->make_immutable >> method still works the same
672 A mutable class accepted C<< Foo->new(undef) >> without complaint,
673 while an immutable class would blow up with an unhelpful error. Now,
674 in both cases we throw a helpful error instead.
676 This "feature" was originally added to allow for cases such as this:
684 return My::Class->new($args);
686 But we decided this is a bad idea and a little too magical, because it
687 can easily mask real errors.
691 Calling C<type> or C<subtype> without the sugar helpers (C<as>,
692 C<where>, C<message>) is now deprecated.
694 As a side effect, this meant we ended up using Perl prototypes on
695 C<as>, and code like this will no longer work:
697 use Moose::Util::TypeConstraints;
698 use Declare::Constraints::Simple -All;
700 subtype 'ArrayOfInts'
702 => IsArrayRef(IsInt);
704 Instead it must be changed to this:
709 where => IsArrayRef(IsInt)
713 If you want to maintain backwards compat with older versions of Moose,
714 you must explicitly test Moose's C<VERSION>:
716 if ( Moose->VERSION < 0.71_01 ) {
717 subtype 'ArrayOfInts'
719 => IsArrayRef(IsInt);
725 where => IsArrayRef(IsInt)
732 We no longer pass the meta-attribute object as a final argument to
733 triggers. This actually changed for inlined code a while back, but the
734 non-inlined version and the docs were still out of date.
736 If by some chance you actually used this feature, the workaround is
737 simple. You fetch the attribute object from out of the C<$self>
738 that is passed as the first argument to trigger, like so:
744 my ( $self, $value ) = @_;
745 my $attr = $self->meta->find_attribute_by_name('foo');
753 If you created a subtype and passed a parent that Moose didn't know
754 about, it simply ignored the parent. Now it automatically creates the
755 parent as a class type. This may not be what you want, but is less
758 You could declare a name with subtype such as "Foo!Bar". Moose would
759 accept this allowed, but if you used it in a parameterized type such
760 as "ArrayRef[Foo!Bar]" it wouldn't work. We now do some vetting on
761 names created via the sugar functions, so that they can only contain
762 alphanumerics, ":", and ".".
766 Methods created via an attribute can now fulfill a C<requires>
767 declaration for a role. Honestly we don't know why Stevan didn't make
768 this work originally, he was just insane or something.
770 Stack traces from inlined code will now report the line and file as
771 being in your class, as opposed to in Moose guts.
775 When a class does not provide all of a role's required methods, the
776 error thrown now mentions all of the missing methods, as opposed to
777 just the first missing method.
779 Moose will no longer inline a constructor for your class unless it
780 inherits its constructor from Moose::Object, and will warn when it
781 doesn't inline. If you want to force inlining anyway, pass
782 C<< replace_constructor => 1 >> to C<make_immutable>.
784 If you want to get rid of the warning, pass C<< inline_constructor =>
789 Removed the (deprecated) C<make_immutable> keyword.
791 Removing an attribute from a class now also removes delegation
792 (C<handles>) methods installed for that attribute. This is correct
793 behavior, but if you were wrongly relying on it you might get bit.
797 Roles now add methods by calling C<add_method>, not
798 C<alias_method>. They make sure to always provide a method object,
799 which will be cloned internally. This means that it is now possible to
800 track the source of a method provided by a role, and even follow its
801 history through intermediate roles. This means that methods added by
802 a role now show up when looking at a class's method list/map.
804 Parameter and Union args are now sorted, this makes Int|Str the same
805 constraint as Str|Int. Also, incoming type constraint strings are
806 normalized to remove all whitespace differences. This is mostly for
807 internals and should not affect outside code.
809 L<Moose::Exporter> will no longer remove a subroutine that the
810 exporting package re-exports. Moose re-exports the Carp::confess
811 function, among others. The reasoning is that we cannot know whether
812 you have also explicitly imported those functions for your own use, so
813 we err on the safe side and always keep them.
817 C<Moose::init_meta> should now be called as a method.
819 New modules for extension writers, L<Moose::Exporter> and
820 L<Moose::Util::MetaRole>.
824 Implemented metaclass traits (and wrote a recipe for it):
826 use Moose -traits => 'Foo'
828 This should make writing small Moose extensions a little
833 Fixed C<coerce> to accept anon types just like C<subtype> can.
836 coerce $some_anon_type => from 'Str' => via { ... };
840 Added C<BUILDARGS>, a new step in C<< Moose::Object->new() >>.
844 Fixed how the C<< is => (ro|rw) >> works with custom defined
845 C<reader>, C<writer> and C<accessor> options. See the below table for
848 is => ro, writer => _foo # turns into (reader => foo, writer => _foo)
849 is => rw, writer => _foo # turns into (reader => foo, writer => _foo)
850 is => rw, accessor => _foo # turns into (accessor => _foo)
851 is => ro, accessor => _foo # error, accesor is rw
855 The C<before/around/after> method modifiers now support regexp
856 matching of method names. NOTE: this only works for classes, it is
857 currently not supported in roles, but, ... patches welcome.
859 The C<has> keyword for roles now accepts the same array ref form that
860 L<Moose>.pm does for classes.
862 A trigger on a read-only attribute is no longer an error, as it's
863 useful to trigger off of the constructor.
865 Subtypes of parameterizable types now are parameterizable types
870 Fixed issue where C<DEMOLISHALL> was eating the value in C<$@>, and so
871 not working correctly. It still kind of eats them, but so does vanilla
876 Inherited attributes may now be extended without restriction on the
877 type ('isa', 'does').
879 The entire set of Moose::Meta::TypeConstraint::* classes were
880 refactored in this release. If you were relying on their internals you
881 should test your code carefully.
885 Documenting the use of '+name' with attributes that come from recently
886 composed roles. It makes sense, people are using it, and so why not
887 just officially support it.
889 The C<< Moose::Meta::Class->create >> method now supports roles.
891 It is now possible to make anonymous enum types by passing C<enum> an
892 array reference instead of the C<< enum $name => @values >>.
896 Added the C<make_immutable> keyword as a shortcut to calling
897 C<make_immutable> on the meta object. This eventually got removed!
899 Made C<< init_arg => undef >> work in Moose. This means "do not accept
900 a constructor parameter for this attribute".
902 Type errors now use the provided message. Prior to this release they
907 Moose is now a postmodern object system :)
909 The Role system was completely refactored. It is 100% backwards
910 compat, but the internals were totally changed. If you relied on the
911 internals then you are advised to test carefully.
913 Added method exclusion and aliasing for Roles in this release.
915 Added the L<Moose::Util::TypeConstraints::OptimizedConstraints>
918 Passing a list of values to an accessor (which is only expecting one
919 value) used to be silently ignored, now it throws an error.
923 Added parameterized types and did a pretty heavy refactoring of the
924 type constraint system.
926 Better framework extensibility and better support for "making your own
929 =head1 0.25 or before
931 Honestly, you shouldn't be using versions of Moose that are this old,
932 so many bug fixes and speed improvements have been made you would be
933 crazy to not upgrade.
935 Also, I am tired of going through the Changelog so I am stopping here,
936 if anyone would like to continue this please feel free.