diff --git a/spec.html b/spec.html index 23857ed25e..bfc46e82a7 100644 --- a/spec.html +++ b/spec.html @@ -8349,10 +8349,11 @@ <h1>%ThrowTypeError% ( )</h1> <h1>MakeConstructor ( _F_ [ , _writablePrototype_ [ , _prototype_ ] ] )</h1> <p>The abstract operation MakeConstructor takes argument _F_ (a function object) and optional arguments _writablePrototype_ (a Boolean) and _prototype_ (an Object). It converts _F_ into a constructor. It performs the following steps when called:</p> <emu-alg> - 1. Assert: _F_ is an ECMAScript function object. - 1. Assert: IsConstructor(_F_) is *false*. - 1. Assert: _F_ is an extensible object that does not have a *"prototype"* own property. - 1. Set _F_.[[Construct]] to the definition specified in <emu-xref href="#sec-ecmascript-function-objects-construct-argumentslist-newtarget"></emu-xref>. + 1. Assert: _F_ is an ECMAScript function object or a built-in function object. + 1. If _F_ is an ECMAScript function object, then + 1. Assert: IsConstructor(_F_) is *false*. + 1. Assert: _F_ is an extensible object that does not have a *"prototype"* own property. + 1. Set _F_.[[Construct]] to the definition specified in <emu-xref href="#sec-ecmascript-function-objects-construct-argumentslist-newtarget"></emu-xref>. 1. Set _F_.[[ConstructorKind]] to ~base~. 1. If _writablePrototype_ is not present, set _writablePrototype_ to *true*. 1. If _prototype_ is not present, then @@ -21135,22 +21136,19 @@ <h1>Runtime Semantics: ClassDefinitionEvaluation</h1> 1. Let _proto_ be ! OrdinaryObjectCreate(_protoParent_). 1. If |ClassBody_opt| is not present, let _constructor_ be ~empty~. 1. Else, let _constructor_ be ConstructorMethod of |ClassBody|. - 1. If _constructor_ is ~empty~, then - 1. If |ClassHeritage_opt| is present, then - 1. Set _constructor_ to the result of parsing the source text - <pre><code class="javascript">constructor(...args) { super(...args); }</code></pre> - using the syntactic grammar with the goal symbol |MethodDefinition[~Yield, ~Await]|. - 1. Else, - 1. Set _constructor_ to the result of parsing the source text - <pre><code class="javascript">constructor() {}</code></pre> - using the syntactic grammar with the goal symbol |MethodDefinition[~Yield, ~Await]|. 1. Set the running execution context's LexicalEnvironment to _classScope_. - 1. Let _constructorInfo_ be ! DefineMethod of _constructor_ with arguments _proto_ and _constructorParent_. - 1. Let _F_ be _constructorInfo_.[[Closure]]. + 1. If _constructor_ is ~empty~, then + 1. Let _steps_ be the algorithm steps defined in <emu-xref href="#sec-default-constructor-functions"></emu-xref>. + 1. Let _F_ be ! CreateBuiltinFunction(_steps_, « [[ConstructorKind]], [[HomeObject]], [[SourceText]] », ~empty~, _constructorParent_, *true*). + 1. Perform ! SetFunctionLength(_F_, *+0*<sub>𝔽</sub>). + 1. Set _F_.[[HomeObject]] to _proto_. + 1. Else, + 1. Let _constructorInfo_ be ! DefineMethod of _constructor_ with arguments _proto_ and _constructorParent_. + 1. Let _F_ be _constructorInfo_.[[Closure]]. + 1. Perform MakeClassConstructor(_F_). 1. Perform SetFunctionName(_F_, _className_). 1. Perform MakeConstructor(_F_, *false*, _proto_). 1. If |ClassHeritage_opt| is present, set _F_.[[ConstructorKind]] to ~derived~. - 1. Perform MakeClassConstructor(_F_). 1. Perform CreateMethodProperty(_proto_, *"constructor"*, _F_). 1. If |ClassBody_opt| is not present, let _methods_ be a new empty List. 1. Else, let _methods_ be NonConstructorMethodDefinitions of |ClassBody|. @@ -21167,6 +21165,23 @@ <h1>Runtime Semantics: ClassDefinitionEvaluation</h1> 1. Perform _classScope_.InitializeBinding(_classBinding_, _F_). 1. Return _F_. </emu-alg> + + <emu-clause id="sec-default-constructor-functions"> + <h1>Default Constructor Functions</h1> + <p>When a Default Constructor Function is called with zero or more arguments which form the rest parameter ..._args_, the following steps are taken:</p> + <emu-alg> + 1. If NewTarget is *undefined*, throw a *TypeError* exception. + 1. Let _F_ be the active function object. + 1. If _F_.[[ConstructorKind]] is ~derived~, then + 1. NOTE: This branch behaves similarly to `constructor(...args) { super(...args); }`. The most notable distinction is that while the aforementioned ECMAScript source text observably calls `%Array.prototype[@@iterator]%`, this abstract operation does not. + 1. Let _func_ be ? _F_.[[GetPrototypeOf]](). + 1. If IsConstructor(_func_) is *false*, throw a *TypeError* exception. + 1. Return ? Construct(_func_, _args_, NewTarget). + 1. Else, + 1. NOTE: This branch behaves similarly to `constructor() {}`. + 1. Return ? OrdinaryCreateFromConstructor(NewTarget, `"%Object.prototype%"`). + </emu-alg> + </emu-clause> </emu-clause> <emu-clause id="sec-runtime-semantics-bindingclassdeclarationevaluation"> @@ -26264,7 +26279,10 @@ <h1>Function.prototype.toString ( )</h1> <p>When the `toString` method is called, the following steps are taken:</p> <emu-alg> 1. Let _func_ be the *this* value. - 1. If _func_ is a <emu-xref href="#sec-built-in-function-objects">built-in function object</emu-xref>, then return an implementation-defined String source code representation of _func_. The representation must have the syntax of a |NativeFunction|. Additionally, if _func_ has an [[InitialName]] internal slot and _func_.[[InitialName]] is a String, the portion of the returned String that would be matched by |NativeFunctionAccessor?| |PropertyName| must be the value of _func_.[[InitialName]]. + 1. If _func_ is a <emu-xref href="#sec-built-in-function-objects">built-in function object</emu-xref>, then + 1. If _func_ has a [[SourceText]] internal slot and _func_.[[SourceText]] is a sequence of Unicode code points, then + 1. Return ! CodePointsToString(_func_.[[SourceText]]). + 1. Return an implementation-defined String source code representation of _func_. The representation must have the syntax of a |NativeFunction|. Additionally, if _func_ has an [[InitialName]] internal slot and _func_.[[InitialName]] is a String, the portion of the returned String that would be matched by |NativeFunctionAccessor?| |PropertyName| must be the value of _func_.[[InitialName]]. 1. If Type(_func_) is Object and _func_ has a [[SourceText]] internal slot and _func_.[[SourceText]] is a sequence of Unicode code points and ! HostHasSourceTextAvailable(_func_) is *true*, then 1. Return ! CodePointsToString(_func_.[[SourceText]]). 1. If Type(_func_) is Object and IsCallable(_func_) is *true*, then return an implementation-defined String source code representation of _func_. The representation must have the syntax of a |NativeFunction|.