1Moose::Manual::Delta(3)User Contributed Perl DocumentatioMnoose::Manual::Delta(3)
2
6 Moose::Manual::Delta - Important Changes in Moose
7
9 version 2.2206
10
12 This documents any important or noteworthy changes in Moose, with a
13 focus on things that affect backwards compatibility. This does
14 duplicate data from the Changes file, but aims to provide more details
15 and when possible workarounds.
16 Besides helping keep up with changes, you can also use this document
18 for finding the lowest version of Moose that supported a given feature.
19 If you encounter a problem and have a solution but don't see it
20 documented here, or think we missed an important feature, please send
21 us a patch.
22
24 Overloading implementation has changed
25 Overloading meta information used to be implemented by a
26 "Class::MOP::Method::Overload" class. This class has been removed,
27 and overloading is now implemented by Class::MOP::Overload.
28 Overloading is not really equivalent to a method, so the former
29 implementation didn't work properly for various cases.
30 All of the overloading-related methods for classes and roles have
32 the same names, but those methods now return Class::MOP::Overload
33 objects.
34 Core support for overloading in roles
36 Roles which use overloading now pass that overloading onto other
37 classes (and roles) which consume that role.
38 This works much like MooseX::Role::WithOverloading, except that we
40 properly detect overloading conflicts during role summation and
41 when applying one role to another. MooseX::Role::WithOverloading
42 did not do any conflict detection.
43 If you want to write code that uses overloading and works with
45 previous versions of Moose and this one, upgrade to
46 MooseX::Role::WithOverloading version 0.15 or greater. That version
47 will detect when Moose itself handles overloading and get out of
48 the way.
49
51 Classes created by Moose are now registered in %INC
52 This means that this will no longer die (and will also no longer
53 try to load "Foo.pm"):
54 {
56 package Foo;
57 use Moose;
58 }
59 # ...
61 use Foo;
63 If you're using the MOP, this behavior will occur when the "create"
65 (or "create_anon_class") method is used, but not when the
66 "initialize" method is used.
67 Moose now uses Module::Runtime instead of Class::Load to load classes
69 Class::Load has always had some weird issues with the ways that it
70 tries to figure out if a class is loaded. For instance, extending
71 an empty package was previously impossible, because Class::Load
72 would think that the class failed to load, even though that is a
73 perfectly valid thing to do. It was also difficult to deal with
74 modules like IO::Handle, which partially populate several other
75 packages when they are loaded (so calling "load_class" on
76 'IO::Handle' followed by 'IO::File' could end up with a broken
77 "IO::File", in some cases).
78 Now, Moose uses the same mechanisms as perl itself to figure out if
80 a class is loaded. A class is considered to be loaded if its entry
81 in %INC is set. Perl sets the %INC entry for you automatically
82 whenever a file is loaded via "use" or "require". Also, as
83 mentioned above, Moose also now sets the %INC entry for any classes
84 defined with it, even if they aren't loaded from a separate file.
85 This does however mean that if you are trying to use Moose with
86 non-Moose classes defined in the same file, then you will need to
87 set %INC manually now, where it may have worked in the past. For
88 instance:
89 {
91 package My::NonMoose;
92 sub new { bless {}, shift }
94 $INC{'My/NonMoose.pm'} = __FILE__;
96 # alternatively:
97 # use Module::Runtime 'module_notional_filename';
98 # $INC{module_notional_filename(__PACKAGE__)} = __FILE__;
99 }
100 {
102 package My::Moose;
103 use Moose;
104 extends 'My::NonMoose';
106 }
107 If you don't do this, you will get an error message about not being
109 able to locate "My::NonMoose" in @INC. We hope that this case will
110 be fairly rare.
111 The Class::Load wrapper functions in Class::MOP have been deprecated
113 "Class::MOP::load_class", "Class::MOP::is_class_loaded", and
114 "Class::MOP::load_first_existing_class" have been deprecated. They
115 have been undocumented and discouraged since version 2.0200. You
116 should replace their use with the corresponding functions in
117 Class::Load, or just use Module::Runtime directly.
118 The non-arrayref forms of "enum" and "duck_type" have been deprecated
120 Originally, "enum" could be called like this:
121 enum('MyType' => qw(foo bar baz))
123 This was confusing, however (since it was different from the syntax
125 for anonymous enum types), and it makes error checking more
126 difficult (since you can't tell just by looking whether
127 "enum('Foo', 'Bar', 'Baz')" was intended to be a type named "Foo"
128 with elements of "Bar" and "Baz", or if this was actually a mistake
129 where someone got the syntax for an anonymous enum type wrong).
130 This all also applies to "duck_type".
131 Calling "enum" and "duck_type" with a list of arguments as
133 described above has been undocumented since version 0.93, and is
134 now deprecated. You should replace
135 enum MyType => qw(foo bar baz);
137 in your code with
139 enum MyType => [qw(foo bar baz)];
141 Moose string exceptions have been replaced by Moose exception objects
143 Previously, Moose threw string exceptions on error conditions,
144 which were not so verbose. All those string exceptions have now
145 been converted to exception objects, which provide very detailed
146 information about the exceptions. These exception objects provide a
147 string overload that matches the previous exception message, so in
148 most cases you should not have to change your code.
149 For learning about the usage of Moose exception objects, read
151 Moose::Manual::Exceptions. Individual exceptions are documented in
152 Moose::Manual::Exceptions::Manifest.
153 This work was funded as part of the GNOME Outreach Program for
155 Women.
156
158 The Num type is now stricter
159 The "Num" type used to accept anything that fits Perl's notion of a
160 number, which included Inf, NaN, and strings like " 1234 \n". We
161 believe that the type constraint should indicate "this is a
162 number", not "this coerces to a number". Therefore, Num now only
163 accepts integers, floating point numbers (both in decimal notation
164 and exponential notation), 0, .0, 0.0, etc.
165 If you want the old behavior you can use the "LaxNum" type in
167 MooseX::Types::LaxNum.
168 You can use Specio instead of core Moose types
170 The Specio distribution is an experimental new type system intended
171 to eventually replace the core Moose types, but yet also work with
172 things like Moo and Mouse and anything else. Right now this is all
173 speculative, but at least you can use Specio with Moose.
174
176 "->init_meta" is even less reliable at loading extensions
177 Previously, calling "MooseX::Foo->init_meta(@_)" (and nothing else)
178 from within your own "init_meta" had a decent chance of doing
179 something useful. This was never supported behavior, and didn't
180 always work anyway. Due to some implementation adjustments, this
181 now has a smaller chance of doing something useful, which could
182 break code that was expecting it to continue doing useful things.
183 Code that does this should instead just call "MooseX::Foo->import({
184 into => $into })".
185 All the Cookbook recipes have been renamed
187 We've given them all descriptive names, rather than numbers. This
188 makes it easier to talk about them, and eliminates the need to
189 renumber recipes in order to reorder them or delete one.
190
192 The parent of a union type is its components' nearest common ancestor
193 Previously, union types considered all of their component types
194 their parent types. This was incorrect because parent types are
195 defined as types that must be satisfied in order for the child type
196 to be satisfied, but in a union, validating as any parent type will
197 validate against the entire union. This has been changed to find
198 the nearest common ancestor for all of its components. For example,
199 a union of "Int|ArrayRef[Int]" now has a parent of "Defined".
200 Union types consider all members in the "is_subtype_of" and
202 "is_a_type_of" methods
203 Previously, a union type would report itself as being of a subtype
204 of a type if any of its member types were subtypes of that type.
205 This was incorrect because any value that passes a subtype
206 constraint must also pass a parent constraint. This has changed so
207 that all of its member types must be a subtype of the specified
208 type.
209 Enum types now work with just one value
211 Previously, an "enum" type needed to have two or more values.
212 Nobody knew why, so we fixed it.
213 Methods defined in UNIVERSAL now appear in the MOP
215 Any method introspection methods that look at methods from parent
216 classes now find methods defined in UNIVERSAL. This includes
217 methods like "$class->get_all_methods" and
218 "$class->find_method_by_name".
219 This also means that you can now apply method modifiers to these
221 methods.
222 Hand-optimized type constraint code causes a deprecation warning
224 If you provide an optimized sub ref for a type constraint, this now
225 causes a deprecation warning. Typically, this comes from passing an
226 "optimize_as" parameter to "subtype", but it could also happen if
227 you create a Moose::Meta::TypeConstraint object directly.
228 Use the inlining feature ("inline_as") added in 2.0100 instead.
230 "Class::Load::load_class" and "is_class_loaded" have been removed
232 The "Class::MOP::load_class" and "Class::MOP::is_class_loaded"
233 subroutines are no longer documented, and will cause a deprecation
234 warning in the future. Moose now uses Class::Load to provide this
235 functionality, and you should do so as well.
236
238 Array and Hash native traits provide a "shallow_clone" method
239 The Array and Hash native traits now provide a "shallow_clone"
240 method, which will return a reference to a new container with the
241 same contents as the attribute's reference.
242
244 Hand-optimized type constraint code is deprecated in favor of inlining
245 Moose allows you to provide a hand-optimized version of a type
246 constraint's subroutine reference. This version allows type
247 constraints to generate inline code, and you should use this
248 inlining instead of providing a hand-optimized subroutine
249 reference.
250 This affects the "optimize_as" sub exported by
252 Moose::Util::TypeConstraints. Use "inline_as" instead.
253 This will start warning in the 2.0300 release.
255
257 More useful type constraint error messages
258 If you have Devel::PartialDump version 0.14 or higher installed,
259 Moose's type constraint error messages will use it to display the
260 invalid value, rather than just displaying it directly. This will
261 generally be much more useful. For instance, instead of this:
262 Attribute (foo) does not pass the type constraint because: Validation failed for 'ArrayRef[Int]' with value ARRAY(0x275eed8)
264 the error message will instead look like
266 Attribute (foo) does not pass the type constraint because: Validation failed for 'ArrayRef[Int]' with value [ "a" ]
268 Note that Devel::PartialDump can't be made a direct dependency at
270 the moment, because it uses Moose itself, but we're considering
271 options to make this easier.
272
274 Roles have their own default attribute metaclass
275 Previously, when a role was applied to a class, it would use the
276 attribute metaclass defined in the class when copying over the
277 attributes in the role. This was wrong, because for instance,
278 using MooseX::FollowPBP in the class would end up renaming all of
279 the accessors generated by the role, some of which may be being
280 called in the role, causing it to break. Roles now keep track of
281 their own attribute metaclass to use by default when being applied
282 to a class (defaulting to Moose::Meta::Attribute). This is
283 modifiable using Moose::Util::MetaRole by passing the
284 "applied_attribute" key to the "role_metaroles" option, as in:
285 Moose::Util::MetaRole::apply_metaroles(
287 for => __PACKAGE__,
288 class_metaroles => {
289 attribute => ['My::Meta::Role::Attribute'],
290 },
291 role_metaroles => {
292 applied_attribute => ['My::Meta::Role::Attribute'],
293 },
294 );
295 Class::MOP has been folded into the Moose dist
297 Moose and Class::MOP are tightly related enough that they have
298 always had to be kept pretty closely in step in terms of versions.
299 Making them into a single dist should simplify the upgrade process
300 for users, as it should no longer be possible to upgrade one
301 without the other and potentially cause issues. No functionality
302 has changed, and this should be entirely transparent.
303 Moose's conflict checking is more robust and useful
305 There are two parts to this. The most useful one right now is that
306 Moose will ship with a "moose-outdated" script, which can be run at
307 any point to list the modules which are installed that conflict
308 with the installed version of Moose. After upgrading Moose,
309 running "moose-outdated | cpanm" should be sufficient to ensure
310 that all of the Moose extensions you use will continue to work.
311 The other part is that Moose's "META.json" file will also specify
313 the conflicts under the "x_conflicts" (now "x_breaks") key. We are
314 working with the Perl tool chain developers to try to get conflicts
315 support added to CPAN clients, and if/when that happens, the
316 metadata already exists, and so the conflict checking will become
317 automatic.
318 The lazy_build attribute feature is discouraged
320 While not deprecated, we strongly discourage you from using this
321 feature.
322 Most deprecated APIs/features are slated for removal in Moose 2.0200
324 Most of the deprecated APIs and features in Moose will start
325 throwing an error in Moose 2.0200. Some of the features will go
326 away entirely, and some will simply throw an error.
327 The things on the chopping block are:
329 • Old public methods in Class::MOP and Moose
331 This includes things like
333 "Class::MOP::Class->get_attribute_map",
334 "Class::MOP::Class->construct_instance", and many others.
335 These were deprecated in Class::MOP 0.80_01, released on
336 April 5, 2009.
337 These methods will be removed entirely in Moose 2.0200.
339 • Old public functions in Class::MOP
341 This include "Class::MOP::subname",
343 "Class::MOP::in_global_destruction", and the
344 "Class::MOP::HAS_ISAREV" constant. The first two were
345 deprecated in 0.84, and the last in 0.80. Class::MOP 0.84
346 was released on May 12, 2009.
347 These functions will be removed entirely in Moose 2.0200.
349 • The "alias" and "excludes" option for role composition
351 These were renamed to "-alias" and "-excludes" in Moose
353 0.89, released on August 13, 2009.
354 Passing these will throw an error in Moose 2.0200.
356 • The old Moose::Util::MetaRole API
358 This include the apply_metaclass_roles() function, as well
360 as passing the "for_class" or any key ending in "_roles" to
361 apply_metaroles(). This was deprecated in Moose 0.93_01,
362 released on January 4, 2010.
363 These will all throw an error in Moose 2.0200.
365 • Passing plain lists to type() or subtype()
367 The old API for these functions allowed you to pass a plain
369 list of parameter, rather than a list of hash references
370 (which is what as(), "where", etc. return). This was
371 deprecated in Moose 0.71_01, released on February 22, 2009.
372 This will throw an error in Moose 2.0200.
374 • The Role subtype
376 This subtype was deprecated in Moose 0.84, released on June
378 26, 2009.
379 This will be removed entirely in Moose 2.0200.
381
383 • New release policy
384 As of the 2.0 release, Moose now has an official release and
386 support policy, documented in Moose::Manual::Support. All API
387 changes will now go through a deprecation cycle of at least one
388 year, after which the deprecated API can be removed. Deprecations
389 and removals will only happen in major releases.
390 In between major releases, we will still make minor releases to add
392 new features, fix bugs, update documentation, etc.
393
395 Configurable stacktraces
396 Classes which use the Moose::Error::Default error class can now
397 have stacktraces disabled by setting the "MOOSE_ERROR_STYLE" env
398 var to "croak". This is experimental, fairly incomplete, and won't
399 work in all cases (because Moose's error system in general is all
400 of these things), but this should allow for reducing at least some
401 of the verbosity in most cases.
402
404 Native Delegations
405 In previous versions of Moose, the Native delegations were created
406 as closures. The generated code was often quite slow compared to
407 doing the same thing by hand. For example, the Array's push
408 delegation ended up doing something like this:
409 push @{ $self->$reader() }, @_;
411 If the attribute was created without a reader, the $reader sub
413 reference followed a very slow code path. Even with a reader, this
414 is still slower than it needs to be.
415 Native delegations are now generated as inline code, just like
417 other accessors, so we can access the slot directly.
418 In addition, native traits now do proper constraint checking in all
420 cases. In particular, constraint checking has been improved for
421 array and hash references. Previously, only the contained type (the
422 "Str" in "HashRef[Str]") would be checked when a new value was
423 added to the collection. However, if there was a constraint that
424 applied to the whole value, this was never checked.
425 In addition, coercions are now called on the whole value.
427 The delegation methods now do more argument checking. All of the
429 methods check that a valid number of arguments were passed to the
430 method. In addition, the delegation methods check that the
431 arguments are sane (array indexes, hash keys, numbers, etc.) when
432 applicable. We have tried to emulate the behavior of Perl builtins
433 as much as possible.
434 Finally, triggers are called whenever the value of the attribute is
436 changed by a Native delegation.
437 These changes are only likely to break code in a few cases.
439 The inlining code may or may not preserve the original reference
441 when changes are made. In some cases, methods which change the
442 value may replace it entirely. This will break tied values.
443 If you have a typed arrayref or hashref attribute where the type
445 enforces a constraint on the whole collection, this constraint will
446 now be checked. It's possible that code which previously ran
447 without errors will now cause the constraint to fail. However,
448 presumably this is a good thing ;)
449 If you are passing invalid arguments to a delegation which were
451 previously being ignored, these calls will now fail.
452 If your code relied on the trigger only being called for a regular
454 writer, that may cause problems.
455 As always, you are encouraged to test before deploying the latest
457 version of Moose to production.
458 Defaults is and default for String, Counter, and Bool
460 A few native traits (String, Counter, Bool) provide default values
461 of "is" and "default" when you created an attribute. Allowing them
462 to provide these values is now deprecated. Supply the value
463 yourself when creating the attribute.
464 The "meta" method
466 Moose and Class::MOP have been cleaned up internally enough to make
467 the "meta" method that you get by default optional. "use Moose" and
468 "use Moose::Role" now can take an additional "-meta_name" option,
469 which tells Moose what name to use when installing the "meta"
470 method. Passing "undef" to this option suppresses generation of the
471 "meta" method entirely. This should be useful for users of modules
472 which also use a "meta" method or function, such as Curses or
473 Rose::DB::Object.
474
476 All deprecated features now warn
477 Previously, deprecation mostly consisted of simply saying "X is
478 deprecated" in the Changes file. We were not very consistent about
479 actually warning. Now, all deprecated features still present in
480 Moose actually give a warning. The warning is issued once per
481 calling package. See Moose::Deprecated for more details.
482 You cannot pass "coerce => 1" unless the attribute's type constraint
484 has a coercion
485 Previously, this was accepted, and it sort of worked, except that
486 if you attempted to set the attribute after the object was created,
487 you would get a runtime error.
488 Now you will get a warning when you attempt to define the
490 attribute.
491 "no Moose", "no Moose::Role", and "no Moose::Exporter" no longer
493 unimport strict and warnings
494 This change was made in 1.05, and has now been reverted. We don't
495 know if the user has explicitly loaded strict or warnings on their
496 own, and unimporting them is just broken in that case.
497 Reversed logic when defining which options can be changed
499 Moose::Meta::Attribute now allows all options to be changed in an
500 overridden attribute. The previous behaviour required each option
501 to be whitelisted using the "legal_options_for_inheritance" method.
502 This method has been removed, and there is a new method,
503 "illegal_options_for_inheritance", which can now be used to prevent
504 certain options from being changeable.
505 In addition, we only throw an error if the illegal option is
507 actually changed. If the superclass didn't specify this option at
508 all when defining the attribute, the subclass version can still add
509 it as an option.
510 Example of overriding this in an attribute trait:
512 package Bar::Meta::Attribute;
514 use Moose::Role;
515 has 'my_illegal_option' => (
517 isa => 'CodeRef',
518 is => 'rw',
519 );
520 around illegal_options_for_inheritance => sub {
522 return ( shift->(@_), qw/my_illegal_option/ );
523 };
524
526 "BUILD" in Moose::Object methods are now called when calling
527 "new_object"
528 Previously, "BUILD" methods would only be called from
529 "Moose::Object::new", but now they are also called when
530 constructing an object via "Moose::Meta::Class::new_object".
531 "BUILD" methods are an inherent part of the object construction
532 process, and this should make "$meta->new_object" actually usable
533 without forcing people to use "$meta->name->new".
534 "no Moose", "no Moose::Role", and "no Moose::Exporter" now unimport
536 strict and warnings
537 In the interest of having "no Moose" clean up everything that "use
538 Moose" does in the calling scope, "no Moose" (as well as all other
539 Moose::Exporter-using modules) now unimports strict and warnings.
540 Metaclass compatibility checking and fixing should be much more robust
542 The metaclass compatibility checking and fixing algorithms have
543 been completely rewritten, in both Class::MOP and Moose. This
544 should resolve many confusing errors when dealing with non-Moose
545 inheritance and with custom metaclasses for things like attributes,
546 constructors, etc. For correct code, the only thing that should
547 require a change is that custom error metaclasses must now inherit
548 from Moose::Error::Default.
549
551 Moose::Meta::TypeConstraint::Class is_subtype_of behavior
552 Earlier versions of is_subtype_of would incorrectly return true
553 when called with itself, its own TC name or its class name as an
554 argument. (i.e. $foo_tc->is_subtype_of('Foo') == 1) This behavior
555 was a caused by "isa" being checked before the class name. The old
556 behavior can be accessed with is_type_of
557
559 Moose::Meta::Attribute::Native::Trait::Code no longer creates reader
560 methods by default
561 Earlier versions of Moose::Meta::Attribute::Native::Trait::Code
562 created read-only accessors for the attributes it's been applied
563 to, even if you didn't ask for it with "is => 'ro'". This incorrect
564 behaviour has now been fixed.
565
567 Moose::Util add_method_modifier behavior
568 add_method_modifier (and subsequently the sugar functions
569 Moose::before, Moose::after, and Moose::around) can now accept
570 arrayrefs, with the same behavior as lists. Types other than
571 arrayref and regexp result in an error.
572
574 Moose::Util::MetaRole API has changed
575 The "apply_metaclass_roles" function is now called
576 "apply_metaroles". The way arguments are supplied has been changed
577 to force you to distinguish between metaroles applied to
578 Moose::Meta::Class (and helpers) versus Moose::Meta::Role.
579 The old API still works, but will warn in a future release, and
581 eventually be removed.
582 Moose::Meta::Role has real attributes
584 The attributes returned by Moose::Meta::Role are now instances of
585 the Moose::Meta::Role::Attribute class, instead of bare hash
586 references.
587 "no Moose" now removes "blessed" and "confess"
589 Moose is now smart enough to know exactly what it exported, even
590 when it re-exports functions from other packages. When you unimport
591 Moose, it will remove these functions from your namespace unless
592 you also imported them directly from their respective packages.
593 If you have a "no Moose" in your code before you call "blessed" or
595 "confess", your code will break. You can either move the "no Moose"
596 call later in your code, or explicitly import the relevant
597 functions from the packages that provide them.
598 Moose::Exporter is smarter about unimporting re-exports
600 The change above comes from a general improvement to
601 Moose::Exporter. It will now unimport any function it exports, even
602 if that function is a re-export from another package.
603 Attributes in roles can no longer override class attributes with "+foo"
605 Previously, this worked more or less accidentally, because role
606 attributes weren't objects. This was never documented, but a few
607 MooseX modules took advantage of this.
608 The composition_class_roles attribute in Moose::Meta::Role is now a
610 method
611 This was done to make it possible for roles to alter the list of
612 composition class roles by applying a method modifiers. Previously,
613 this was an attribute and MooseX modules override it. Since that no
614 longer works, this was made a method.
615 This should be an attribute, so this may switch back to being an
617 attribute in the future if we can figure out how to make this work.
618
620 Calling $object->new() is no longer deprecated
621 We decided to undeprecate this. Now it just works.
622 Both "get_method_map" and "get_attribute_map" is deprecated
624 These metaclass methods were never meant to be public, and they are
625 both now deprecated. The work around if you still need the
626 functionality they provided is to iterate over the list of names
627 manually.
628 my %fields = map { $_ => $meta->get_attribute($_) } $meta->get_attribute_list;
630 This was actually a change in Class::MOP, but this version of Moose
632 requires a version of Class::MOP that includes said change.
633
635 Added Native delegation for Code refs
636 See Moose::Meta::Attribute::Native::Trait::Code for details.
637 Calling $object->new() is deprecated
639 Moose has long supported this, but it's never really been
640 documented, and we don't think this is a good practice. If you want
641 to construct an object from an existing object, you should provide
642 some sort of alternate constructor like "$object->clone".
643 Calling "$object->new" now issues a warning, and will be an error
645 in a future release.
646 Moose no longer warns if you call "make_immutable" for a class with
648 mutable ancestors
649 While in theory this is a good thing to warn about, we found so
650 many exceptions to this that doing this properly became quite
651 problematic.
652
654 New Native delegation methods from List::Util and List::MoreUtils
655 In particular, we now have "reduce", "shuffle", "uniq", and
656 "natatime".
657 The Moose::Exporter with_caller feature is now deprecated
659 Use "with_meta" instead. The "with_caller" option will start
660 warning in a future release.
661 Moose now warns if you call "make_immutable" for a class with mutable
663 ancestors
664 This is dangerous because modifying a class after a subclass has
665 been immutabilized will lead to incorrect results in the subclass,
666 due to inlining, caching, etc. This occasionally happens
667 accidentally, when a class loads one of its subclasses in the
668 middle of its class definition, so pointing out that this may cause
669 issues should be helpful. Metaclasses (classes that inherit from
670 Class::MOP::Object) are currently exempt from this check, since at
671 the moment we aren't very consistent about which metaclasses we
672 immutabilize.
673 "enum" and "duck_type" now take arrayrefs for all forms
675 Previously, calling these functions with a list would take the
676 first element of the list as the type constraint name, and use the
677 remainder as the enum values or method names. This makes the
678 interface inconsistent with the anon-type forms of these functions
679 (which must take an arrayref), and a free-form list where the first
680 value is sometimes special is hard to validate (and harder to give
681 reasonable error messages for). These functions have been changed
682 to take arrayrefs in all their forms - so, "enum 'My::Type' =>
683 [qw(foo bar)]" is now the preferred way to create an enum type
684 constraint. The old syntax still works for now, but it will
685 hopefully be deprecated and removed in a future release.
686
688 Moose::Meta::Attribute::Native has been moved into the Moose core from
689 MooseX::AttributeHelpers. Major changes include:
690 "traits", not "metaclass"
692 Method providers are only available via traits.
693 "handles", not "provides" or "curries"
695 The "provides" syntax was like core Moose "handles => HASHREF"
696 syntax, but with the keys and values reversed. This was confusing,
697 and AttributeHelpers now uses "handles => HASHREF" in a way that
698 should be intuitive to anyone already familiar with how it is used
699 for other attributes.
700 The "curries" functionality provided by AttributeHelpers has been
702 generalized to apply to all cases of "handles => HASHREF", though
703 not every piece of functionality has been ported (currying with a
704 CODEREF is not supported).
705 "empty" is now "is_empty", and means empty, not non-empty
707 Previously, the "empty" method provided by Arrays and Hashes
708 returned true if the attribute was not empty (no elements). Now it
709 returns true if the attribute is empty. It was also renamed to
710 "is_empty", to reflect this.
711 "find" was renamed to "first", and "first" and "last" were removed
713 List::Util refers to the functionality that we used to provide
714 under "find" as first, so that will likely be more familiar (and
715 will fit in better if we decide to add more List::Util functions).
716 "first" and "last" were removed, since their functionality is
717 easily duplicated with curries of "get".
718 Helpers that take a coderef of one argument now use $_
720 Subroutines passed as the first argument to "first", "map", and
721 "grep" now receive their argument in $_ rather than as a parameter
722 to the subroutine. Helpers that take a coderef of two or more
723 arguments remain using the argument list (there are technical
724 limitations to using $a and $b like "sort" does).
725 See Moose::Meta::Attribute::Native for the new documentation.
727 The "alias" and "excludes" role parameters have been renamed to
729 "-alias" and "-excludes". The old names still work, but new code should
730 use the new names, and eventually the old ones will be deprecated and
731 removed.
732
734 "use Moose -metaclass => 'Foo'" now does alias resolution, just like
735 "-traits" (and the "metaclass" and "traits" options to "has").
736 Added two functions "meta_class_alias" and "meta_attribute_alias" to
738 Moose::Util, to simplify aliasing metaclasses and metatraits. This is a
739 wrapper around the old
740 package Moose::Meta::Class::Custom::Trait::FooTrait;
742 sub register_implementation { 'My::Meta::Trait' }
743 way of doing this.
745
747 When an attribute generates no accessors, we now warn. This is to help
748 users who forget the "is" option. If you really do not want any
749 accessors, you can use "is => 'bare'". You can maintain back compat
750 with older versions of Moose by using something like:
751 ($Moose::VERSION >= 0.84 ? is => 'bare' : ())
753 When an accessor overwrites an existing method, we now warn. To work
755 around this warning (if you really must have this behavior), you can
756 explicitly remove the method before creating it as an accessor:
757 sub foo {}
759 __PACKAGE__->meta->remove_method('foo');
761 has foo => (
763 is => 'ro',
764 );
765 When an unknown option is passed to "has", we now warn. You can silence
767 the warning by fixing your code. :)
768 The "Role" type has been deprecated. On its own, it was useless, since
770 it just checked "$object->can('does')". If you were using it as a
771 parent type, just call role_type('Role::Name') to create an appropriate
772 type instead.
773
775 "use Moose::Exporter;" now imports "strict" and "warnings" into
776 packages that use it.
777
779 "DEMOLISHALL" and "DEMOLISH" now receive an argument indicating whether
780 or not we are in global destruction.
781
783 Type constraints no longer run coercions for a value that already
784 matches the constraint. This may affect some (arguably buggy) edge
785 case coercions that rely on side effects in the "via" clause.
786
788 Moose::Exporter now accepts the "-metaclass" option for easily
789 overriding the metaclass (without metaclass). This works for classes
790 and roles.
791
793 Added a "duck_type" sugar function to Moose::Util::TypeConstraints to
794 make integration with non-Moose classes easier. It simply checks if
795 "$obj->can()" a list of methods.
796 A number of methods (mostly inherited from Class::MOP) have been
798 renamed with a leading underscore to indicate their internal-ness. The
799 old method names will still work for a while, but will warn that the
800 method has been renamed. In a few cases, the method will be removed
801 entirely in the future. This may affect MooseX authors who were using
802 these methods.
803
805 Calling "subtype" with a name as the only argument now throws an
806 exception. If you want an anonymous subtype do:
807 my $subtype = subtype as 'Foo';
809 This is related to the changes in version 0.71_01.
811 The "is_needed" method in Moose::Meta::Method::Destructor is now only
813 usable as a class method. Previously, it worked as a class or object
814 method, with a different internal implementation for each version.
815 The internals of making a class immutable changed a lot in Class::MOP
817 0.78_02, and Moose's internals have changed along with it. The external
818 "$metaclass->make_immutable" method still works the same way.
819
821 A mutable class accepted "Foo->new(undef)" without complaint, while an
822 immutable class would blow up with an unhelpful error. Now, in both
823 cases we throw a helpful error instead.
824 This "feature" was originally added to allow for cases such as this:
826 my $args;
828 if ( something() ) {
830 $args = {...};
831 }
832 return My::Class->new($args);
834 But we decided this is a bad idea and a little too magical, because it
836 can easily mask real errors.
837
839 Calling "type" or "subtype" without the sugar helpers ("as", "where",
840 "message") is now deprecated.
841 As a side effect, this meant we ended up using Perl prototypes on "as",
843 and code like this will no longer work:
844 use Moose::Util::TypeConstraints;
846 use Declare::Constraints::Simple -All;
847 subtype 'ArrayOfInts'
849 => as 'ArrayRef'
850 => IsArrayRef(IsInt);
851 Instead it must be changed to this:
853 subtype(
855 'ArrayOfInts' => {
856 as => 'ArrayRef',
857 where => IsArrayRef(IsInt)
858 }
859 );
860 If you want to maintain backwards compat with older versions of Moose,
862 you must explicitly test Moose's "VERSION":
863 if ( Moose->VERSION < 0.71_01 ) {
865 subtype 'ArrayOfInts'
866 => as 'ArrayRef'
867 => IsArrayRef(IsInt);
868 }
869 else {
870 subtype(
871 'ArrayOfInts' => {
872 as => 'ArrayRef',
873 where => IsArrayRef(IsInt)
874 }
875 );
876 }
877
879 We no longer pass the meta-attribute object as a final argument to
880 triggers. This actually changed for inlined code a while back, but the
881 non-inlined version and the docs were still out of date.
882 If by some chance you actually used this feature, the workaround is
884 simple. You fetch the attribute object from out of the $self that is
885 passed as the first argument to trigger, like so:
886 has 'foo' => (
888 is => 'ro',
889 isa => 'Any',
890 trigger => sub {
891 my ( $self, $value ) = @_;
892 my $attr = $self->meta->find_attribute_by_name('foo');
893 # ...
895 }
896 );
897
899 If you created a subtype and passed a parent that Moose didn't know
900 about, it simply ignored the parent. Now it automatically creates the
901 parent as a class type. This may not be what you want, but is less
902 broken than before.
903 You could declare a name with subtype such as "Foo!Bar". Moose would
905 accept this allowed, but if you used it in a parameterized type such as
906 "ArrayRef[Foo!Bar]" it wouldn't work. We now do some vetting on names
907 created via the sugar functions, so that they can only contain
908 alphanumerics, ":", and ".".
909
911 Methods created via an attribute can now fulfill a "requires"
912 declaration for a role. Honestly we don't know why Stevan didn't make
913 this work originally, he was just insane or something.
914 Stack traces from inlined code will now report the line and file as
916 being in your class, as opposed to in Moose guts.
917
919 When a class does not provide all of a role's required methods, the
920 error thrown now mentions all of the missing methods, as opposed to
921 just the first missing method.
922 Moose will no longer inline a constructor for your class unless it
924 inherits its constructor from Moose::Object, and will warn when it
925 doesn't inline. If you want to force inlining anyway, pass
926 "replace_constructor => 1" to "make_immutable".
927 If you want to get rid of the warning, pass inline_constructor => 0.
929
931 Removed the (deprecated) "make_immutable" keyword.
932 Removing an attribute from a class now also removes delegation
934 ("handles") methods installed for that attribute. This is correct
935 behavior, but if you were wrongly relying on it you might get bit.
936
938 Roles now add methods by calling "add_method", not "alias_method". They
939 make sure to always provide a method object, which will be cloned
940 internally. This means that it is now possible to track the source of a
941 method provided by a role, and even follow its history through
942 intermediate roles. This means that methods added by a role now show
943 up when looking at a class's method list/map.
944 Parameter and Union args are now sorted, this makes Int|Str the same
946 constraint as Str|Int. Also, incoming type constraint strings are
947 normalized to remove all whitespace differences. This is mostly for
948 internals and should not affect outside code.
949 Moose::Exporter will no longer remove a subroutine that the exporting
951 package re-exports. Moose re-exports the Carp::confess function, among
952 others. The reasoning is that we cannot know whether you have also
953 explicitly imported those functions for your own use, so we err on the
954 safe side and always keep them.
955
957 "Moose::init_meta" should now be called as a method.
958 New modules for extension writers, Moose::Exporter and
960 Moose::Util::MetaRole.
961
963 Implemented metaclass traits (and wrote a recipe for it):
964 use Moose -traits => 'Foo'
966 This should make writing small Moose extensions a little easier.
968
970 Fixed "coerce" to accept anon types just like "subtype" can. So that
971 you can do:
972 coerce $some_anon_type => from 'Str' => via { ... };
974
976 Added "BUILDARGS", a new step in "Moose::Object->new()".
977
979 Fixed how the "is => (ro|rw)" works with custom defined "reader",
980 "writer" and "accessor" options. See the below table for details:
981 is => ro, writer => _foo # turns into (reader => foo, writer => _foo)
983 is => rw, writer => _foo # turns into (reader => foo, writer => _foo)
984 is => rw, accessor => _foo # turns into (accessor => _foo)
985 is => ro, accessor => _foo # error, accesor is rw
986
988 The "before/around/after" method modifiers now support regexp matching
989 of method names. NOTE: this only works for classes, it is currently not
990 supported in roles, but, ... patches welcome.
991 The "has" keyword for roles now accepts the same array ref form that
993 Moose.pm does for classes.
994 A trigger on a read-only attribute is no longer an error, as it's
996 useful to trigger off of the constructor.
997 Subtypes of parameterizable types now are parameterizable types
999 themselves.
1000
1002 Fixed issue where "DEMOLISHALL" was eating the value in $@, and so not
1003 working correctly. It still kind of eats them, but so does vanilla
1004 perl.
1005
1007 Inherited attributes may now be extended without restriction on the
1008 type ('isa', 'does').
1009 The entire set of Moose::Meta::TypeConstraint::* classes were
1011 refactored in this release. If you were relying on their internals you
1012 should test your code carefully.
1013
1015 Documenting the use of '+name' with attributes that come from recently
1016 composed roles. It makes sense, people are using it, and so why not
1017 just officially support it.
1018 The "Moose::Meta::Class->create" method now supports roles.
1020 It is now possible to make anonymous enum types by passing "enum" an
1022 array reference instead of the "enum $name => @values".
1023
1025 Added the "make_immutable" keyword as a shortcut to calling
1026 "make_immutable" on the meta object. This eventually got removed!
1027 Made "init_arg => undef" work in Moose. This means "do not accept a
1029 constructor parameter for this attribute".
1030 Type errors now use the provided message. Prior to this release they
1032 didn't.
1033
1035 Moose is now a postmodern object system :)
1036 The Role system was completely refactored. It is 100% backwards compat,
1038 but the internals were totally changed. If you relied on the internals
1039 then you are advised to test carefully.
1040 Added method exclusion and aliasing for Roles in this release.
1042 Added the Moose::Util::TypeConstraints::OptimizedConstraints module.
1044 Passing a list of values to an accessor (which is only expecting one
1046 value) used to be silently ignored, now it throws an error.
1047
1049 Added parameterized types and did a pretty heavy refactoring of the
1050 type constraint system.
1051 Better framework extensibility and better support for "making your own
1053 Moose".
1054
1056 Honestly, you shouldn't be using versions of Moose that are this old,
1057 so many bug fixes and speed improvements have been made you would be
1058 crazy to not upgrade.
1059 Also, I am tired of going through the Changelog so I am stopping here,
1061 if anyone would like to continue this please feel free.
1062
1064 • Stevan Little <stevan@cpan.org>
1065 • Dave Rolsky <autarch@urth.org>
1067 • Jesse Luehrs <doy@cpan.org>
1069 • Shawn M Moore <sartak@cpan.org>
1071 • יובל קוג'מן (Yuval Kogman) <nothingmuch@woobling.org>
1073 • Karen Etheridge <ether@cpan.org>
1075 • Florian Ragwitz <rafl@debian.org>
1077 • Hans Dieter Pearcey <hdp@cpan.org>
1079 • Chris Prather <chris@prather.org>
1081 • Matt S Trout <mstrout@cpan.org>
1083
1085 This software is copyright (c) 2006 by Infinity Interactive, Inc.
1086 This is free software; you can redistribute it and/or modify it under
1088 the same terms as the Perl 5 programming language system itself.
1089perl v5.38.0 2023-07-23 Moose::Manual::Delta(3)