Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Adds Decorator Metadata #10

Open
wants to merge 18 commits into
base: decorators
Choose a base branch
from
Open

Adds Decorator Metadata #10

Changes from 1 commit
Commits
Show all changes
18 commits
Select commit Hold shift + click to select a range
14425b5
Add Class and Class Element Decorators and `accessor` Keyword
Apr 5, 2021
1f42b91
Non-normative fixes
pzuraq Mar 6, 2023
bcd170c
Remove dynamic [[HomeObject]] from decorator return values
pzuraq Mar 6, 2023
a2b63dd
Throw an error if the value passed to `addInitializer` is not callable
pzuraq Mar 7, 2023
5d556fe
Set the name of the `addInitializer` function
pzuraq Mar 7, 2023
f604983
Fixes based on feedback from @jmdyck
pzuraq Mar 7, 2023
e86128e
Merge pull request #5 from pzuraq/remove-dynamic-home-object
pzuraq Apr 12, 2023
ca35c74
Merge pull request #7 from pzuraq/throw-error-if-initializer-is-not-c…
pzuraq Apr 12, 2023
444a531
Merge pull request #8 from pzuraq/set-add-initializer-function-name
pzuraq Apr 12, 2023
50ce824
Call decorators with their natural `this` value.
pzuraq Apr 12, 2023
39e6e35
Remove setFunctionName from decorator application
pzuraq Apr 12, 2023
43b16ea
Merge pull request #11 from pzuraq/remove-set-function-name
pzuraq Apr 12, 2023
823f1bf
Merge pull request #6 from pzuraq/call-decorators-with-correct-this
pzuraq Apr 12, 2023
c4465e4
Reverse initializer order
pzuraq May 16, 2023
ceb4225
Adds Decorator Metadata
pzuraq Mar 7, 2023
90938f8
Use null instead of Object.prototype as root metadata object prototype
pzuraq May 1, 2023
fb0852e
Update spec based on feedback
pzuraq May 16, 2023
b5c0f4e
more feedback
pzuraq May 17, 2023
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
24 changes: 17 additions & 7 deletions spec.html
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -24330,7 +24330,7 @@ <h1>
_name_: a String, a Symbol, or a Private Name,
_initializers_: a List of function objects,
_decorationState_: a Record with a field [[Finished]] (a Boolean),
_metadataObj_: an Object,
_metadataObj_: an Object or ~empty~,
Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This can't actually be ~empty~, can it? We only call this method if there are decorators.

That would be better handled by making this just "an Object" and adding an Assert: _metadataObj_ is not ~empty~ at the callsites.

Copy link
Owner Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Ah that's a good point, I can add conditionals there as well.

optional _isStatic_: a Boolean,
): an Object
</h1>
Expand Down Expand Up @@ -24362,7 +24362,7 @@ <h1>
1. Perform ! CreateDataPropertyOrThrow(_contextObj_, *"name"*, _name_).
1. Let _addInitializer_ be CreateAddInitializerFunction(_initializers_, _decorationState_).
1. Perform ! CreateDataPropertyOrThrow(_contextObj_, *"addInitializer"*, _addInitializer_).
1. Perform ! CreateDataPropertyOrThrow(_contextObj_, *"metadata"*, _metadataObj_).
1. If _metadata_ is not ~empty~, perform ! CreateDataPropertyOrThrow(_contextObj_, *"metadata"*, _metadataObj_).
1. Return _contextObj_.
</emu-alg>
</emu-clause>
Expand All @@ -24373,7 +24373,7 @@ <h1>
_homeObject_: an Object,
_elementRecord_: a ClassElementDefinition Record,
_extraInitializers_: a List of function objects,
_metadataObj_: an Object,
_metadataObj_: an Object or ~empty~,
_isStatic_: a Boolean,
): either a normal completion containing ~unused~, or an abrupt completion
</h1>
Expand Down Expand Up @@ -25237,6 +25237,8 @@ <h1>
1. Perform CreateMethodProperty(_proto_, *"constructor"*, _F_).
1. If |ClassBody?| is not present, let _elements_ be a new empty List.
1. Else, let _elements_ be NonConstructorElements of |ClassBody|.
1. Let _hasDecorators_ be *false*.
1. If _decorators_ is not empty, set _hasDecorators_ to *true*.
1. Let _instanceElements_ be a new empty List.
1. Let _staticElements_ be a new empty List.
1. For each |ClassElement| _e_ of _elements_, do
Expand All @@ -25248,6 +25250,7 @@ <h1>
1. Return ? _result_.
1. Let _element_ be _result_.[[Value]].
1. If _element_ is a ClassElementDefinition Record, then
1. If _e_.[[Decorators]] is not empty, set _hasDecorators_ to *true*.
1. If IsStatic of _e_ is *false*, append _element_ to _instanceElements_.
1. Else, append _element_ to _staticElements_.
1. Else,
Expand All @@ -25256,9 +25259,11 @@ <h1>
1. Set the running execution context's LexicalEnvironment to _env_.
1. Let _instanceExtraInitializers_ be a new empty List.
1. Let _staticExtraInitializers_ be a new empty List.
1. Let _metadataParent_ be ? Get(_constructorParent_, @@metadata).
1. If _metadataParent_ is *undefined*, let _metadataParent_ be *null*.
1. Let _metadataObj_ be OrdinaryObjectCreate(_metadataParent_).
1. Let _metadataObj_ be ~empty~.
1. If _hasDecorators_ is *true*, then
1. If |ClassHeritage?| is present, let _metadataParent_ be ? Get(_constructorParent_, @@metadata).
1. Else, let _metadataParent_ be *null*.
1. Set _metadataObj_ to OrdinaryObjectCreate(_metadataParent_).
Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Not that class extends null {} actually works for construction, but won't this mean that @dec class extends null {} will throw?

Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

If so, that seems better then doing what class extends null {} does (until we're able to fix extending null)

Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

If that's the case, I'd maybe call it out in some sort of editorial note to indicate that the behavior is intended.

1. For each element _e_ of _staticElements_, do
1. If _e_ is a ClassElementDefinition Record and _e_.[[Kind]] is not ~field~, then
Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

OrdinaryObjectCreate only accepts an object or null, but _constructorParent_[@@metadata] could be any ECMAScript value.

Probably we shuold:

  • if _constructorParent_[@@metadata] is undefined, fallback to null
  • if it's a different primitive, throw a TypeError

Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Or maybe always throw, given that there is the Function.prototype[Symbol.metadata] fallback and thus undefined must have been explicitly set.

1. Let _result_ be Completion(ApplyDecoratorsAndDefineMethod(_F_, _e_, _staticExtraInitializers_, _metadataObj_, *true*)).
Expand Down Expand Up @@ -25292,7 +25297,11 @@ <h1>
1. Set the running execution context's PrivateEnvironment to _outerPrivateEnvironment_.
1. Return ? _result_.
1. Set _F_ to _newF_.[[Value]].
1. Perform ! DefinePropertyOrThrow(_F_, @@metadata, PropertyDescriptor { [[Value]]: _metadataObj_, [[Writable]]: *true*, [[Enumerable]]: *false*, [[Configurable]]: *true* }).
1. If _metadataObj_ is not ~empty~, then
1. Let _setMetadataResult_ be Completion(DefinePropertyOrThrow(_F_, @@metadata, PropertyDescriptor { [[Value]]: _metadataObj_, [[Writable]]: *true*, [[Enumerable]]: *false*, [[Configurable]]: *true* })).
1. If _setMetadataResult_ is an abrupt completion, then
1. Set the running execution context's PrivateEnvironment to _outerPrivateEnvironment_.
1. Return ? _setMetadataResult_.
1. If _classBinding_ is not *undefined*, then
1. Perform _classEnv_.InitializeBinding(_classBinding_, _F_).
1. For each element _initializer_ of _staticExtraInitializers_, do
Expand Down Expand Up @@ -30619,6 +30628,7 @@ <h1>Properties of the Function Prototype Object</h1>
<li>does not have a *"prototype"* property.</li>
<li>has a *"length"* property whose value is *+0*<sub>𝔽</sub>.</li>
<li>has a *"name"* property whose value is the empty String.</li>
<li>has a @@metadata property whose value is *null*, which is non-writable and non-configurable to prevent tampering that could be used to globally add metadata to all classes.</li>
Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I think this should be its own section - we only really do "name" and "length" like this.

Compare, for example, GeneratorFunction.prototype [ @@toStringTag ]. (Except of course it should be non-configurable, and then it can be just "the value" rather than "the initial value".)

I'm neutral on whether to include the explanation in that section as well or just leave it out entirely.

Copy link
Owner Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Ah, I was looking for something similar and couldn't find it, I'll update!

</ul>
<emu-note>
<p>The Function prototype object is specified to be a function object to ensure compatibility with ECMAScript code that was created prior to the ECMAScript 2015 specification.</p>
Expand Down