12.1.5.1 Runtime Semantics: InitializeBoundName(name, value, environment)

1. Assert: Type(name) is String.
2. If environment is not undefined, then
   1. Let env be the EnvironmentRecord component of environment.
   2. Perform env.InitializeBinding(name, value).
   3. Return NormalCompletion(undefined).
3. Else
   1. Let lhs be ResolveBinding(name).
   2. Return PutValue(lhs, value).

12.2.1.1 Static Semantics: CoveredParenthesizedExpression

1. Return the result of parsing the lexical token stream matched by CoverParenthesizedExpressionAndArrowParameterList_[Yield] using either ParenthesizedExpression or ParenthesizedExpression_[Yield] as the goal symbol depending upon whether the _[Yield] grammar parameter was present when CoverParenthesizedExpressionAndArrowParameterList was matched.

12.2.1.2 Static Semantics: HasName

See also: 14.1.8, 14.2.7, 14.4.7, 14.5.6.

1. Let expr be CoveredParenthesizedExpression of CoverParenthesizedExpressionAndArrowParameterList.
2. If IsFunctionDefinition of expr is false, return false.
3. Return HasName of expr.

12.2.1.3 Static Semantics: IsFunctionDefinition

See also: 12.2.10.2, 12.3.1.2, 12.4.2, 12.5.2, 12.6.1, 12.7.1, 12.8.1, 12.9.1, 12.10.1, 12.11.1, 12.12.1, 12.13.1, 12.14.2, 12.15.1, 14.1.11, 14.4.9, 14.5.8.

1. Return false.

1. Let expr be CoveredParenthesizedExpression of CoverParenthesizedExpressionAndArrowParameterList.
2. Return IsFunctionDefinition of expr.

12.2.1.4 Static Semantics: IsIdentifierRef

See also: 12.3.1.4.

1. Return true.

1. Return false.

12.2.1.5 Static Semantics: IsValidSimpleAssignmentTarget

See also: 12.1.3, 12.2.10.3, 12.3.1.5, 12.4.3, 12.5.3, 12.6.2, 12.7.2, 12.8.2, 12.9.2, 12.10.2, 12.11.2, 12.12.2, 12.13.2, 12.14.3, 12.15.2.

1. Return false.

1. Let expr be CoveredParenthesizedExpression of CoverParenthesizedExpressionAndArrowParameterList.
2. Return IsValidSimpleAssignmentTarget of expr.

12.2.2.1 Runtime Semantics: Evaluation

1. Return ResolveThisBinding( ) .

12.2.4.1 Runtime Semantics: Evaluation

1. Return null.

1. Return false if BooleanLiteral is the token false.
2. Return true if BooleanLiteral is the token true.

1. Return the number whose value is MV of NumericLiteral as defined in 11.8.3.

1. Return the StringValue of StringLiteral as defined in 11.8.4.2.

12.2.5.1 Static Semantics: ElisionWidth

1. Return the numeric value 1.

1. Let preceding be the ElisionWidth of Elision.
2. Return preceding+1.

12.2.5.2 Runtime Semantics: ArrayAccumulation

With parameters array and nextIndex.

1. Let padding be the ElisionWidth of Elision; if Elision is not present, use the numeric value zero.
2. Let initResult be the result of evaluating AssignmentExpression.
3. Let initValue be GetValue(initResult).
4. ReturnIfAbrupt(initValue).
5. Let created be CreateDataProperty(array, ToString(ToUint32(nextIndex+padding)), initValue).
6. Assert: created is true.
7. Return nextIndex+padding+1.

1. Let padding be the ElisionWidth of Elision; if Elision is not present, use the numeric value zero.
2. Return the result of performing ArrayAccumulation for SpreadElement with arguments array and nextIndex+padding.

1. Let postIndex be the result of performing ArrayAccumulation for ElementList with arguments array and nextIndex.
2. ReturnIfAbrupt(postIndex).
3. Let padding be the ElisionWidth of Elision; if Elision is not present, use the numeric value zero.
4. Let initResult be the result of evaluating AssignmentExpression.
5. Let initValue be GetValue(initResult).
6. ReturnIfAbrupt(initValue).
7. Let created be CreateDataProperty(array, ToString(ToUint32(postIndex+padding)), initValue).
8. Assert: created is true.
9. Return postIndex+padding+1.

1. Let postIndex be the result of performing ArrayAccumulation for ElementList with arguments array and nextIndex.
2. ReturnIfAbrupt(postIndex).
3. Let padding be the ElisionWidth of Elision; if Elision is not present, use the numeric value zero.
4. Return the result of performing ArrayAccumulation for SpreadElement with arguments array and postIndex+padding.

1. Let spreadRef be the result of evaluating AssignmentExpression.
2. Let spreadObj be GetValue(spreadRef).
3. Let iterator be GetIterator(spreadObj).
4. ReturnIfAbrupt(iterator).
5. Repeat
   1. Let next be IteratorStep(iterator).
   2. ReturnIfAbrupt(next).
   3. If next is false, return nextIndex.
   4. Let nextValue be IteratorValue(next).
   5. ReturnIfAbrupt(nextValue).
   6. Let status be CreateDataProperty(array, ToString(nextIndex), nextValue).
   7. Assert: status is true .
   8. Let nextIndex be nextIndex + 1.

12.2.5.3 Runtime Semantics: Evaluation

1. Let array be ArrayCreate(0).
2. Let pad be the ElisionWidth of Elision; if Elision is not present, use the numeric value zero.
3. Perform Set(array, "length", pad, false).
4. NOTE: The above Set cannot fail because of the nature of the object returned by ArrayCreate.
5. Return array.

1. Let array be ArrayCreate(0).
2. Let len be the result of performing ArrayAccumulation for ElementList with arguments array and 0.
3. ReturnIfAbrupt(len).
4. Perform Set(array, "length", len, false).
5. NOTE: The above Set cannot fail because of the nature of the object returned by ArrayCreate.
6. Return array.

1. Let array be ArrayCreate(0).
2. Let len be the result of performing ArrayAccumulation for ElementList with arguments array and 0.
3. ReturnIfAbrupt(len).
4. Let padding be the ElisionWidth of Elision; if Elision is not present, use the numeric value zero.
5. Perform Set(array, "length", ToUint32(padding+len), false).
6. NOTE: The above Set cannot fail because of the nature of the object returned by ArrayCreate.
7. Return array.

12.2.6.1 Static Semantics: Early Errors

• It is a Syntax Error if HasDirectSuper of MethodDefinition is true.

In addition to describing an actual object initializer the ObjectLiteral productions are also used as a cover grammar for ObjectAssignmentPattern (12.14.5). and may be recognized as part of a CoverParenthesizedExpressionAndArrowParameterList. When ObjectLiteral appears in a context where ObjectAssignmentPattern is required the following Early Error rules are not applied. In addition, they are not applied when initially parsing a CoverParenthesizedExpressionAndArrowParameterList.

• Always throw a Syntax Error if code matches this production.

12.2.6.2 Static Semantics: ComputedPropertyContains

With parameter symbol.

See also: 14.3.2, 14.4.3, 14.5.5.

1. Return false.

1. Return the result of ComputedPropertyName Contains symbol.

12.2.6.3 Static Semantics: Contains

With parameter symbol.

See also: 5.3, 12.3.1.1, 14.1.4, 14.2.3, 14.4.4, 14.5.4.

1. If symbol is MethodDefinition, return true.
2. Return the result of ComputedPropertyContains for MethodDefinition with argument symbol.

1. If symbol is a ReservedWord, return false.
2. If symbol is an Identifier and StringValue of symbol is the same value as the StringValue of IdentifierName, return true;
3. Return false.

12.2.6.4 Static Semantics: HasComputedPropertyKey

See also: 14.3.4, 14.4.5

1. If HasComputedPropertyKey of PropertyDefinitionList is true, return true.
2. Return HasComputedPropertyKey of PropertyDefinition.

1. Return false.

1. Return IsComputedPropertyKey of PropertyName.

12.2.6.5 Static Semantics: IsComputedPropertyKey

1. Return false.

1. Return true.

12.2.6.6 Static Semantics: PropName

See also: 14.3.6, 14.4.10, 14.5.12

1. Return StringValue of IdentifierReference.

1. Return PropName of PropertyName.

1. Return StringValue of IdentifierName.

1. Return a String value whose code units are the SV of the StringLiteral.

1. Let nbr be the result of forming the value of the NumericLiteral.
2. Return ToString(nbr).

1. Return empty.

12.2.6.7 Static Semantics: PropertyNameList

1. If PropName of PropertyDefinition is empty, return a new empty List.
2. Return a new List containing PropName of PropertyDefinition.

1. Let list be PropertyNameList of PropertyDefinitionList.
2. If PropName of PropertyDefinition is empty, return list.
3. Append PropName of PropertyDefinition to the end of list.
4. Return list.

12.2.6.8 Runtime Semantics: Evaluation

1. Return ObjectCreate(%ObjectPrototype%).

1. Let obj be ObjectCreate(%ObjectPrototype%).
2. Let status be the result of performing PropertyDefinitionEvaluation of PropertyDefinitionList with arguments obj and true.
3. ReturnIfAbrupt(status).
4. Return obj.

1. Return StringValue of IdentifierName.

1. Return a String value whose code units are the SV of the StringLiteral.

1. Let nbr be the result of forming the value of the NumericLiteral.
2. Return ToString(nbr).

1. Let exprValue be the result of evaluating AssignmentExpression.
2. Let propName be GetValue(exprValue).
3. ReturnIfAbrupt(propName).
4. Return ToPropertyKey(propName).

12.2.6.9 Runtime Semantics: PropertyDefinitionEvaluation

With parameter object and enumerable.

See also: 14.3.9, 14.4.13, B.3.1

1. Let status be the result of performing PropertyDefinitionEvaluation of PropertyDefinitionList with arguments object and enumerable.
2. ReturnIfAbrupt(status).
3. Return the result of performing PropertyDefinitionEvaluation of PropertyDefinition with arguments object and enumerable.

1. Let propName be StringValue of IdentifierReference.
2. Let exprValue be the result of evaluating IdentifierReference.
3. ReturnIfAbrupt(exprValue).
4. Let propValue be GetValue(exprValue).
5. ReturnIfAbrupt(propValue).
6. Assert: enumerable is true.
7. Return CreateDataPropertyOrThrow(object, propName, propValue).

1. Let propKey be the result of evaluating PropertyName.
2. ReturnIfAbrupt(propKey).
3. Let exprValueRef be the result of evaluating AssignmentExpression.
4. Let propValue be GetValue(exprValueRef).
5. ReturnIfAbrupt(propValue).
6. If IsAnonymousFunctionDefinition(AssignmentExpression) is true, then
   1. Let hasNameProperty be HasOwnProperty(propValue, "name").
   2. ReturnIfAbrupt(hasNameProperty).
   3. If hasNameProperty is false, perform SetFunctionName(propValue, propKey).
7. Assert: enumerable is true.
8. Return CreateDataPropertyOrThrow(object, propKey, propValue).

12.2.8.1 Static Semantics: Early Errors

• It is a Syntax Error if BodyText of RegularExpressionLiteral cannot be recognized using the goal symbol Pattern of the ECMAScript RegExp grammar specified in 21.2.1.

• It is a Syntax Error if FlagText of RegularExpressionLiteral contains any code points other than "g", "i", "m", "u", or "y", or if it contains the same code point more than once.

12.2.8.2 Runtime Semantics: Evaluation

1. Let pattern be the String value consisting of the UTF16Encoding of each code point of BodyText of RegularExpressionLiteral.
2. Let flags be the String value consisting of the UTF16Encoding of each code point of FlagText of RegularExpressionLiteral.
3. Return RegExpCreate(pattern, flags).

12.2.9.1 Static Semantics: TemplateStrings

With parameter raw.

1. If raw is false, then
   1. Let string be the TV of NoSubstitutionTemplate.
2. Else,
   1. Let string be the TRV of NoSubstitutionTemplate.
3. Return a List containing the single element, string.

1. If raw is false, then
   1. Let head be the TV of TemplateHead.
2. Else,
   1. Let head be the TRV of TemplateHead.
3. Let tail be TemplateStrings of TemplateSpans with argument raw.
4. Return a List containing head followed by the element, in order of tail.

1. If raw is false, then
   1. Let tail be the TV of TemplateTail.
2. Else,
   1. Let tail be the TRV of TemplateTail.
3. Return a List containing the single element, tail.

1. Let middle be TemplateStrings of TemplateMiddleList with argument raw.
2. If raw is false, then
   1. Let tail be the TV of TemplateTail.
3. Else,
   1. Let tail be the TRV of TemplateTail.
4. Return a List containing the elements, in order, of middle followed by tail.

1. If raw is false, then
   1. Let string be the TV of TemplateMiddle.
2. Else,
   1. Let string be the TRV of TemplateMiddle.
3. Return a List containing the single element, string.

1. Let front be TemplateStrings of TemplateMiddleList with argument raw.
2. If raw is false, then
   1. Let last be the TV of TemplateMiddle.
3. Else,
   1. Let last be the TRV of TemplateMiddle.
4. Append last as the last element of the List front.
5. Return front.

12.2.9.2 Runtime Semantics: ArgumentListEvaluation

See also: 12.3.6.1

1. Let templateLiteral be this TemplateLiteral.
2. Let siteObj be GetTemplateObject(templateLiteral).
3. Return a List containing the one element which is siteObj.

1. Let templateLiteral be this TemplateLiteral.
2. Let siteObj be GetTemplateObject(templateLiteral).
3. Let firstSub be the result of evaluating Expression.
4. ReturnIfAbrupt(firstSub).
5. Let restSub be SubstitutionEvaluation of TemplateSpans.
6. ReturnIfAbrupt(restSub).
7. Assert: restSub is a List.
8. Return a List whose first element is siteObj, whose second elements is firstSub, and whose subsequent elements are the elements of restSub, in order. restSub may contain no elements.

12.2.9.3 Runtime Semantics: GetTemplateObject ( templateLiteral )

The abstract operation GetTemplateObject is called with a grammar production, templateLiteral, as an argument. It performs the following steps:

1. Let rawStrings be TemplateStrings of templateLiteral with argument true.
2. Let ctx be the running execution context.
3. Let realm be the ctx's Realm.
4. Let templateRegistry be realm.[[templateMap]].
5. For each element e of templateRegistry, do
   1. If e.[[strings]] and rawStrings contain the same values in the same order, then
      1. Return e.[[array]].
6. Let cookedStrings be TemplateStrings of templateLiteral with argument false.
7. Let count be the number of elements in the List cookedStrings.
8. Let template be ArrayCreate(count).
9. Let rawObj be ArrayCreate(count).
10. Let index be 0.
11. Repeat while index < count
    1. Let prop be ToString(index).
    2. Let cookedValue be the String value cookedStrings[index].
    3. Call template.[[DefineOwnProperty]](prop, PropertyDescriptor{[[Value]]: cookedValue, [[Enumerable]]: true, [[Writable]]: false, [[Configurable]]: false}).
    4. Let rawValue be the String value rawStrings[index].
    5. Call rawObj.[[DefineOwnProperty]](prop, PropertyDescriptor{[[Value]]: rawValue, [[Enumerable]]: true, [[Writable]]: false, [[Configurable]]: false}).
    6. Let index be index+1.
12. Perform SetIntegrityLevel(rawObj, "frozen").
13. Call template.[[DefineOwnProperty]]("raw", PropertyDescriptor{[[Value]]: rawObj, [[Writable]]: false, [[Enumerable]]: false, [[Configurable]]: false}).
14. Perform SetIntegrityLevel(template, "frozen").
15. Append the Record{[[strings]]: rawStrings, [[array]]: template} to templateRegistry.
16. Return template.

12.2.9.4 Runtime Semantics: SubstitutionEvaluation

1. Return an empty List.

1. Return the result of SubstitutionEvaluation of TemplateMiddleList.

1. Let sub be the result of evaluating Expression.
2. ReturnIfAbrupt(sub).
3. Return a List containing only sub.

1. Let preceding be the result of SubstitutionEvaluation of TemplateMiddleList .
2. ReturnIfAbrupt(preceding).
3. Let next be the result of evaluating Expression.
4. ReturnIfAbrupt(next).
5. Append next as the last element of the List preceding.
6. Return preceding.

12.2.9.5 Runtime Semantics: Evaluation

1. Return the String value whose code units are the elements of the TV of NoSubstitutionTemplate as defined in 11.8.6.

1. Let head be the TV of TemplateHead as defined in 11.8.6.
2. Let sub be the result of evaluating Expression.
3. Let middle be ToString(sub).
4. ReturnIfAbrupt(middle).
5. Let tail be the result of evaluating TemplateSpans .
6. ReturnIfAbrupt(tail).
7. Return the String value whose code units are the elements of head followed by the elements of middle followed by the elements of tail.

1. Let tail be the TV of TemplateTail as defined in 11.8.6.
2. Return the string consisting of the code units of tail.

1. Let head be the result of evaluating TemplateMiddleList.
2. ReturnIfAbrupt(head).
3. Let tail be the TV of TemplateTail as defined in 11.8.6.
4. Return the string whose code units are the elements of head followed by the elements of tail.

1. Let head be the TV of TemplateMiddle as defined in 11.8.6.
2. Let sub be the result of evaluating Expression.
3. Let middle be ToString(sub).
4. ReturnIfAbrupt(middle).
5. Return the sequence of code units consisting of the code units of head followed by the elements of middle.

1. Let rest be the result of evaluating TemplateMiddleList .
2. ReturnIfAbrupt(rest).
3. Let middle be the TV of TemplateMiddle as defined in 11.8.6.
4. Let sub be the result of evaluating Expression.
5. Let last be ToString(sub).
6. ReturnIfAbrupt(last).
7. Return the sequence of code units consisting of the elements of rest followed by the code units of middle followed by the elements of last.

12.2.10.1 Static Semantics: Early Errors

• It is a Syntax Error if the lexical token sequence matched by CoverParenthesizedExpressionAndArrowParameterList cannot be parsed with no tokens left over using ParenthesizedExpression as the goal symbol.

• All Early Errors rules for ParenthesizedExpression and its derived productions also apply to CoveredParenthesizedExpression of CoverParenthesizedExpressionAndArrowParameterList.

12.2.10.2 Static Semantics: IsFunctionDefinition

See also: 12.2.1.3, 12.3.1.2, 12.4.2, 12.5.2, 12.6.1, 12.7.1, 12.8.1, 12.9.1, 12.10.1, 12.11.1, 12.12.1, 12.13.1, 12.14.2, 12.15.1, 14.1.11, 14.4.9, 14.5.8.

1. Return IsFunctionDefinition of Expression.

12.2.10.3 Static Semantics: IsValidSimpleAssignmentTarget

See also: 12.1.3, 12.2.1.5, 12.3.1.5, 12.4.3, 12.5.3, 12.6.2, 12.7.2, 12.8.2, 12.9.2, 12.10.2, 12.11.2, 12.12.2, 12.13.2, 12.14.3, 12.15.2.

1. Return IsValidSimpleAssignmentTarget of Expression.

12.2.10.4 Runtime Semantics: Evaluation

1. Let expr be CoveredParenthesizedExpression of CoverParenthesizedExpressionAndArrowParameterList.
2. Return the result of evaluating expr.

1. Return the result of evaluating Expression. This may be of type Reference.

12.3.1.1 Static Semantics: Contains

With parameter symbol.

See also: 5.3, 12.2.6.3, 14.1.4, 14.2.3, 14.4.4, 14.5.4

1. If MemberExpression Contains symbol is true, return true.
2. If symbol is a ReservedWord, return false.
3. If symbol is an Identifier and StringValue of symbol is the same value as the StringValue of IdentifierName, return true;
4. Return false.

1. If symbol is the ReservedWord super, return true.
2. If symbol is a ReservedWord, return false.
3. If symbol is an Identifier and StringValue of symbol is the same value as the StringValue of IdentifierName, return true;
4. Return false.

1. If CallExpression Contains symbol is true, return true.
2. If symbol is a ReservedWord, return false.
3. If symbol is an Identifier and StringValue of symbol is the same value as the StringValue of IdentifierName, return true;
4. Return false.

12.3.1.2 Static Semantics: IsFunctionDefinition

See also: 12.2.1.3, 12.2.10.2, 12.4.2, 12.5.2, 12.6.1, 12.7.1, 12.8.1, 12.9.1, 12.10.1, 12.11.1, 12.12.1, 12.13.1, 12.14.2, 12.15.1, 14.1.11, 14.4.9, 14.5.8.

1. Return false.

12.3.1.3 Static Semantics: IsDestructuring

See also: 13.7.5.6.

1. If PrimaryExpression is either an ObjectLiteral or an ArrayLiteral, return true.
2. Return false.

1. Return false.

12.3.1.4 Static Semantics: IsIdentifierRef

See also: 12.2.1.4.

1. Return false.

12.3.1.5 Static Semantics: IsValidSimpleAssignmentTarget

See also: 12.1.3, 12.2.1.5, 12.2.10.3, 12.4.3, 12.5.3, 12.6.2, 12.7.2, 12.8.2, 12.9.2, 12.10.2, 12.11.2, 12.12.2, 12.13.2, 12.14.3, 12.15.2.

1. Return true.

1. Return false.

12.3.4.1 Runtime Semantics: Evaluation

1. Let ref be the result of evaluating MemberExpression.
2. Let func be GetValue(ref).
3. ReturnIfAbrupt(func).
4. If Type(ref) is Reference and IsPropertyReference(ref) is false and GetReferencedName(ref) is "eval", then
   1. If SameValue(func, %eval%) is true, then
      1. Let argList be ArgumentListEvaluation(Arguments).
      2. ReturnIfAbrupt(argList).
      3. If argList has no elements, return undefined.
      4. Let evalText be the first element of argList.
      5. If the source code matching this CallExpression is strict code, let strictCaller be true. Otherwise let strictCaller be false.
      6. Let evalRealm be the running execution context's Realm.
      7. Return PerformEval(evalText, evalRealm, strictCaller, true). .
5. If Type(ref) is Reference, then
   1. If IsPropertyReference(ref) is true, then
      1. Let thisValue be GetThisValue(ref).
   2. Else, the base of ref is an Environment Record
      1. Let refEnv be GetBase(ref).
      2. Let thisValue be refEnv.WithBaseObject().
6. Else Type(ref) is not Reference,
   1. Let thisValue be undefined.
7. Let thisCall be this CallExpression.
8. Let tailCall be IsInTailPosition(thisCall). (See 14.6.1)
9. Return EvaluateDirectCall(func, thisValue, Arguments, tailCall).

A CallExpression evaluation that executes step 4.a.vii is a direct eval.

1. Let ref be the result of evaluating CallExpression.
2. Let thisCall be this CallExpression
3. Let tailCall be IsInTailPosition(thisCall). (See 14.6.1)
4. Return EvaluateCall(ref, Arguments, tailCall).

12.3.4.2 Runtime Semantics: EvaluateCall( ref, arguments, tailPosition )

The abstract operation EvaluateCall takes as arguments a value ref, a syntactic grammar production arguments, and a Boolean argument tailPosition. It performs the following steps:

1. Let func be GetValue(ref).
2. ReturnIfAbrupt(func).
3. If Type(ref) is Reference, then
   1. If IsPropertyReference(ref) is true, then
      1. Let thisValue be GetThisValue(ref).
   2. Else, the base of ref is an Environment Record
      1. Let refEnv be GetBase(ref).
      2. Let thisValue be refEnv.WithBaseObject().
4. Else Type(ref) is not Reference,
   1. Let thisValue be undefined.
5. Return EvaluateDirectCall(func, thisValue, arguments, tailPosition).

12.3.4.3 Runtime Semantics: EvaluateDirectCall( func, thisValue, arguments, tailPosition )

The abstract operation EvaluateDirectCall takes as arguments a value func, a value thisValue, a syntactic grammar production arguments, and a Boolean argument tailPosition. It performs the following steps:

1. Let argList be ArgumentListEvaluation(arguments).
2. ReturnIfAbrupt(argList).
3. If Type(func) is not Object, throw a TypeError exception.
4. If IsCallable(func) is false, throw a TypeError exception.
5. If tailPosition is true, perform PrepareForTailCall().
6. Let result be Call(func, thisValue, argList).
7. Assert: If tailPosition is true, the above call will not return here, but instead evaluation will continue as if the following return has already occurred.
8. Assert: If result is not an abrupt completion then Type(result) is an ECMAScript language type.
9. Return result.

12.3.5.1 Runtime Semantics: Evaluation

1. Let propertyNameReference be the result of evaluating Expression.
2. Let propertyNameValue be GetValue(propertyNameReference).
3. Let propertyKey be ToPropertyKey(propertyNameValue).
4. ReturnIfAbrupt(propertyKey).
5. If the code matched by the syntactic production that is being evaluated is strict mode code, let strict be true, else let strict be false.
6. Return MakeSuperPropertyReference(propertyKey, strict).

1. Let propertyKey be StringValue of IdentifierName.
2. If the code matched by the syntactic production that is being evaluated is strict mode code, let strict be true, else let strict be false.
3. Return MakeSuperPropertyReference(propertyKey, strict).

1. Let newTarget be GetNewTarget().
2. If newTarget is undefined, throw a ReferenceError exception.
3. Let func be GetSuperConstructor().
4. ReturnIfAbrupt(func).
5. Let argList be ArgumentListEvaluation of Arguments.
6. ReturnIfAbrupt(argList).
7. Let result be Construct(func, argList, newTarget).
8. ReturnIfAbrupt(result).
9. Let thisER be GetThisEnvironment( ).
10. Return thisER.BindThisValue(result).

12.3.5.2 Runtime Semantics: GetSuperConstructor ( )

The abstract operation GetSuperConstructor performs the following steps:

1. Let envRec be GetThisEnvironment( ).
2. Assert: envRec is a function Environment Record.
3. Let activeFunction be envRec.[[FunctionObject]].
4. Let superConstructor be activeFunction.[[GetPrototypeOf]]().
5. ReturnIfAbrupt(superConstructor).
6. If IsConstructor(superConstructor) is false, throw a TypeError exception.
7. Return superConstructor.

12.3.5.3 Runtime Semantics: MakeSuperPropertyReference(propertyKey, strict)

The abstract operation MakeSuperPropertyReference with arguments propertyKey and strict performs the following steps:

1. Let env be GetThisEnvironment( ).
2. If env.HasSuperBinding() is false, throw a ReferenceError exception.
3. Let actualThis be env.GetThisBinding().
4. ReturnIfAbrupt(actualThis).
5. Let baseValue be env.GetSuperBase().
6. Let bv be RequireObjectCoercible(baseValue).
7. ReturnIfAbrupt(bv).
8. Return a value of type Reference that is a Super Reference whose base value is bv, whose referenced name is propertyKey, whose thisValue is actualThis, and whose strict reference flag is strict.

12.3.6.1 Runtime Semantics: ArgumentListEvaluation

See also: 12.2.9.2

1. Return an empty List.

1. Let ref be the result of evaluating AssignmentExpression.
2. Let arg be GetValue(ref).
3. ReturnIfAbrupt(arg).
4. Return a List whose sole item is arg.

1. Let list be an empty List.
2. Let spreadRef be the result of evaluating AssignmentExpression.
3. Let spreadObj be GetValue(spreadRef).
4. Let iterator be GetIterator(spreadObj).
5. ReturnIfAbrupt(iterator).
6. Repeat
   1. Let next be IteratorStep(iterator).
   2. ReturnIfAbrupt(next).
   3. If next is false, return list.
   4. Let nextArg be IteratorValue(next).
   5. ReturnIfAbrupt(nextArg).
   6. Append nextArg as the last element of list.

1. Let precedingArgs be the result of evaluating ArgumentList.
2. ReturnIfAbrupt(precedingArgs).
3. Let ref be the result of evaluating AssignmentExpression.
4. Let arg be GetValue(ref).
5. ReturnIfAbrupt(arg).
6. Append arg to the end of precedingArgs.
7. Return precedingArgs.

1. Let precedingArgs be the result of evaluating ArgumentList.
2. Let spreadRef be the result of evaluating AssignmentExpression.
3. Let iterator be GetIterator(GetValue(spreadRef) ).
4. ReturnIfAbrupt(iterator).
5. Repeat
   1. Let next be IteratorStep(iterator).
   2. ReturnIfAbrupt(next).
   3. If next is false, return precedingArgs.
   4. Let nextArg be IteratorValue(next).
   5. ReturnIfAbrupt(nextArg).
   6. Append nextArg as the last element of precedingArgs.

12.3.7.1 Runtime Semantics: Evaluation

1. Let tagRef be the result of evaluating MemberExpression.
2. Let thisCall be this MemberExpression.
3. Let tailCall be IsInTailPosition(thisCall). (See 14.6.1)
4. Return EvaluateCall(tagRef, TemplateLiteral, tailCall).

1. Let tagRef be the result of evaluating CallExpression.
2. Let thisCall be this CallExpression.
3. Let tailCall be IsInTailPosition(thisCall). (See 14.6.1)
4. Return EvaluateCall(tagRef, TemplateLiteral, tailCall).

12.3.8.1 Runtime Semantics: Evaluation

1. Return GetNewTarget().

12.4.4.1 Runtime Semantics: Evaluation

1. Let lhs be the result of evaluating LeftHandSideExpression.
2. Let oldValue be ToNumber(GetValue(lhs)).
3. ReturnIfAbrupt(oldValue).
4. Let newValue be the result of adding the value 1 to oldValue, using the same rules as for the + operator (see 12.7.5).
5. Let status be PutValue(lhs, newValue).
6. ReturnIfAbrupt(status).
7. Return oldValue.

12.4.5.1 Runtime Semantics: Evaluation

1. Let lhs be the result of evaluating LeftHandSideExpression.
2. Let oldValue be ToNumber(GetValue(lhs)).
3. ReturnIfAbrupt(oldValue).
4. Let newValue be the result of subtracting the value 1 from oldValue, using the same rules as for the - operator (12.7.5).
5. Let status be PutValue(lhs, newValue).
6. ReturnIfAbrupt(status).
7. Return oldValue.

12.5.4.1 Static Semantics: Early Errors

• It is a Syntax Error if the UnaryExpression is contained in strict mode code and the derived UnaryExpression is PrimaryExpression : IdentifierReference.

• It is a Syntax Error if the derived UnaryExpression is
  PrimaryExpression : CoverParenthesizedExpressionAndArrowParameterList
  and CoverParenthesizedExpressionAndArrowParameterList ultimately derives a phrase that, if used in place of UnaryExpression, would produce a Syntax Error according to these rules. This rule is recursively applied.

12.5.4.2 Runtime Semantics: Evaluation

1. Let ref be the result of evaluating UnaryExpression.
2. ReturnIfAbrupt(ref).
3. If Type(ref) is not Reference, return true.
4. If IsUnresolvableReference(ref) is true, then
   1. Assert: IsStrictReference(ref) is false.
   2. Return true.
5. If IsPropertyReference(ref) is true, then
   1. If IsSuperReference(ref), throw a ReferenceError exception.
   2. Let baseObj be ToObject(GetBase(ref)).
   3. Assert: baseObj is not an abrupt completion.
   4. Let deleteStatus be baseObj.[[Delete]](GetReferencedName(ref)).
   5. ReturnIfAbrupt(deleteStatus).
   6. If deleteStatus is false and IsStrictReference(ref) is true, throw a TypeError exception.
   7. Return deleteStatus.
6. Else ref is a Reference to an Environment Record binding,
   1. Let bindings be GetBase(ref).
   2. Return bindings.DeleteBinding(GetReferencedName(ref)).

12.5.5.1 Runtime Semantics: Evaluation

1. Let expr be the result of evaluating UnaryExpression.
2. Let status be GetValue(expr).
3. ReturnIfAbrupt(status).
4. Return undefined.

12.5.6.1 Runtime Semantics: Evaluation

1. Let val be the result of evaluating UnaryExpression.
2. If Type(val) is Reference, then
   1. If IsUnresolvableReference(val) is true, return "undefined".
3. Let val be GetValue(val).
4. ReturnIfAbrupt(val).
5. Return a String according to { REF _Ref327355399 \h \* MERGEFORMAT }Table 35.

12.5.7.1 Runtime Semantics: Evaluation

1. Let expr be the result of evaluating UnaryExpression.
2. Let oldValue be ToNumber(GetValue(expr)).
3. ReturnIfAbrupt(oldValue).
4. Let newValue be the result of adding the value 1 to oldValue, using the same rules as for the + operator (see 12.7.5).
5. Let status be PutValue(expr, newValue).
6. ReturnIfAbrupt(status).
7. Return newValue.

12.5.8.1 Runtime Semantics: Evaluation

1. Let expr be the result of evaluating UnaryExpression.
2. Let oldValue be ToNumber(GetValue(expr)).
3. ReturnIfAbrupt(oldValue).
4. Let newValue be the result of subtracting the value 1 from oldValue, using the same rules as for the - operator (see 12.7.5).
5. Let status be PutValue(expr, newValue).
6. ReturnIfAbrupt(status).
7. Return newValue.

12.5.9.1 Runtime Semantics: Evaluation

1. Let expr be the result of evaluating UnaryExpression.
2. Return ToNumber(GetValue(expr)).

12.5.10.1 Runtime Semantics: Evaluation

1. Let expr be the result of evaluating UnaryExpression.
2. Let oldValue be ToNumber(GetValue(expr)).
3. ReturnIfAbrupt(oldValue).
4. If oldValue is NaN, return NaN.
5. Return the result of negating oldValue; that is, compute a Number with the same magnitude but opposite sign.

12.5.11.1 Runtime Semantics: Evaluation

1. Let expr be the result of evaluating UnaryExpression.
2. Let oldValue be ToInt32(GetValue(expr)).
3. ReturnIfAbrupt(oldValue).
4. Return the result of applying bitwise complement to oldValue. The result is a signed 32-bit integer.

12.5.12.1 Runtime Semantics: Evaluation

1. Let expr be the result of evaluating UnaryExpression.
2. Let oldValue be ToBoolean(GetValue(expr)).
3. ReturnIfAbrupt(oldValue).
4. If oldValue is true, return false.
5. Return true.

12.6.3.1 Applying the * Operator

The * MultiplicativeOperator performs multiplication, producing the product of its operands. Multiplication is commutative. Multiplication is not always associative in ECMAScript, because of finite precision.

The result of a floating-point multiplication is governed by the rules of IEEE 754-2008 binary double-precision arithmetic:

• If either operand is NaN, the result is NaN.

• The sign of the result is positive if both operands have the same sign, negative if the operands have different signs.

• Multiplication of an infinity by a zero results in NaN.

• Multiplication of an infinity by an infinity results in an infinity. The sign is determined by the rule already stated above.

• Multiplication of an infinity by a finite nonzero value results in a signed infinity. The sign is determined by the rule already stated above.

• In the remaining cases, where neither an infinity nor NaN is involved, the product is computed and rounded to the nearest representable value using IEEE 754-2008 round-to-nearest mode. If the magnitude is too large to represent, the result is then an infinity of appropriate sign. If the magnitude is too small to represent, the result is then a zero of appropriate sign. The ECMAScript language requires support of gradual underflow as defined by IEEE 754-2008.

12.6.3.2 Applying the / Operator

The / MultiplicativeOperator performs division, producing the quotient of its operands. The left operand is the dividend and the right operand is the divisor. ECMAScript does not perform integer division. The operands and result of all division operations are double-precision floating-point numbers. The result of division is determined by the specification of IEEE 754-2008 arithmetic:

• If either operand is NaN, the result is NaN.

• The sign of the result is positive if both operands have the same sign, negative if the operands have different signs.

• Division of an infinity by an infinity results in NaN.

• Division of an infinity by a zero results in an infinity. The sign is determined by the rule already stated above.

• Division of an infinity by a nonzero finite value results in a signed infinity. The sign is determined by the rule already stated above.

• Division of a finite value by an infinity results in zero. The sign is determined by the rule already stated above.

• Division of a zero by a zero results in NaN; division of zero by any other finite value results in zero, with the sign determined by the rule already stated above.

• Division of a nonzero finite value by a zero results in a signed infinity. The sign is determined by the rule already stated above.

• In the remaining cases, where neither an infinity, nor a zero, nor NaN is involved, the quotient is computed and rounded to the nearest representable value using IEEE 754-2008 round-to-nearest mode. If the magnitude is too large to represent, the operation overflows; the result is then an infinity of appropriate sign. If the magnitude is too small to represent, the operation underflows and the result is a zero of the appropriate sign. The ECMAScript language requires support of gradual underflow as defined by IEEE 754-2008.

12.6.3.3 Applying the % Operator

The % MultiplicativeOperator yields the remainder of its operands from an implied division; the left operand is the dividend and the right operand is the divisor.

The result of a floating-point remainder operation as computed by the % operator is not the same as the “remainder” operation defined by IEEE 754-2008. The IEEE 754-2008 “remainder” operation computes the remainder from a rounding division, not a truncating division, and so its behaviour is not analogous to that of the usual integer remainder operator. Instead the ECMAScript language defines % on floating-point operations to behave in a manner analogous to that of the Java integer remainder operator; this may be compared with the C library function fmod.

The result of an ECMAScript floating-point remainder operation is determined by the rules of IEEE arithmetic:

• If either operand is NaN, the result is NaN.

• The sign of the result equals the sign of the dividend.

• If the dividend is an infinity, or the divisor is a zero, or both, the result is NaN.

• If the dividend is finite and the divisor is an infinity, the result equals the dividend.

• If the dividend is a zero and the divisor is nonzero and finite, the result is the same as the dividend.

• In the remaining cases, where neither an infinity, nor a zero, nor NaN is involved, the floating-point remainder r from a dividend n and a divisor d is defined by the mathematical relation r = n − (d × q) where q is an integer that is negative only if n/d is negative and positive only if n/d is positive, and whose magnitude is as large as possible without exceeding the magnitude of the true mathematical quotient of n and d. r is computed and rounded to the nearest representable value using IEEE 754-2008 round-to-nearest mode.

12.7.3.1 Runtime Semantics: Evaluation

1. Let lref be the result of evaluating AdditiveExpression.
2. Let lval be GetValue(lref).
3. ReturnIfAbrupt(lval).
4. Let rref be the result of evaluating MultiplicativeExpression.
5. Let rval be GetValue(rref).
6. ReturnIfAbrupt(rval).
7. Let lprim be ToPrimitive(lval).
8. ReturnIfAbrupt(lprim).
9. Let rprim be ToPrimitive(rval).
10. ReturnIfAbrupt(rprim).
11. If Type(lprim) is String or Type(rprim) is String, then
    1. Let lstr be ToString(lprim).
    2. ReturnIfAbrupt(lstr).
    3. Let rstr be ToString(rprim).
    4. ReturnIfAbrupt(rstr).
    5. Return the String that is the result of concatenating lstr and rstr.
12. Let lnum be ToNumber(lprim).
13. ReturnIfAbrupt(lnum).
14. Let rnum be ToNumber(rprim).
15. ReturnIfAbrupt(rnum).
16. Return the result of applying the addition operation to lnum and rnum. See the Note below 12.7.5.

12.7.4.1 Runtime Semantics: Evaluation

1. Let lref be the result of evaluating AdditiveExpression.
2. Let lval be GetValue(lref).
3. ReturnIfAbrupt(lval).
4. Let rref be the result of evaluating MultiplicativeExpression.
5. Let rval be GetValue(rref).
6. ReturnIfAbrupt(rval).
7. Let lnum be ToNumber(lval).
8. ReturnIfAbrupt(lnum).
9. Let rnum be ToNumber(rval).
10. ReturnIfAbrupt(rnum).
11. Return the result of applying the subtraction operation to lnum and rnum. See the note below 12.7.5.

12.8.3.1 Runtime Semantics: Evaluation

1. Let lref be the result of evaluating ShiftExpression.
2. Let lval be GetValue(lref).
3. ReturnIfAbrupt(lval).
4. Let rref be the result of evaluating AdditiveExpression.
5. Let rval be GetValue(rref).
6. ReturnIfAbrupt(rval).
7. Let lnum be ToInt32(lval).
8. ReturnIfAbrupt(lnum).
9. Let rnum be ToUint32(rval).
10. ReturnIfAbrupt(rnum).
11. Let shiftCount be the result of masking out all but the least significant 5 bits of rnum, that is, compute rnum & 0x1F.
12. Return the result of left shifting lnum by shiftCount bits. The result is a signed 32-bit integer.

12.8.4.1 Runtime Semantics: Evaluation

1. Let lref be the result of evaluating ShiftExpression.
2. Let lval be GetValue(lref).
3. ReturnIfAbrupt(lval).
4. Let rref be the result of evaluating AdditiveExpression.
5. Let rval be GetValue(rref).
6. ReturnIfAbrupt(rval).
7. Let lnum be ToInt32(lval).
8. ReturnIfAbrupt(lnum).
9. Let rnum be ToUint32(rval).
10. ReturnIfAbrupt(rnum).
11. Let shiftCount be the result of masking out all but the least significant 5 bits of rnum, that is, compute rnum & 0x1F.
12. Return the result of performing a sign-extending right shift of lnum by shiftCount bits. The most significant bit is propagated. The result is a signed 32-bit integer.

12.8.5.1 Runtime Semantics: Evaluation

1. Let lref be the result of evaluating ShiftExpression.
2. Let lval be GetValue(lref).
3. ReturnIfAbrupt(lval).
4. Let rref be the result of evaluating AdditiveExpression.
5. Let rval be GetValue(rref).
6. ReturnIfAbrupt(rval).
7. Let lnum be ToUint32(lval).
8. ReturnIfAbrupt(lnum).
9. Let rnum be ToUint32(rval).
10. ReturnIfAbrupt(rnum).
11. Let shiftCount be the result of masking out all but the least significant 5 bits of rnum, that is, compute rnum & 0x1F.
12. Return the result of performing a zero-filling right shift of lnum by shiftCount bits. Vacated bits are filled with zero. The result is an unsigned 32-bit integer.

12.14.5.1 Static Semantics: Early Errors

• It is a Syntax Error if IsValidSimpleAssignmentTarget of IdentifierReference is false.

• It is a Syntax Error if LeftHandSideExpression is either an ObjectLiteral or an ArrayLiteral and if the lexical token sequence matched by LeftHandSideExpression cannot be parsed with no tokens left over using AssignmentPattern as the goal symbol.

• It is a Syntax Error if LeftHandSideExpression is neither an ObjectLiteral nor an ArrayLiteral and IsValidSimpleAssignmentTarget(LeftHandSideExpression) is false.

12.14.5.2 Runtime Semantics: DestructuringAssignmentEvaluation

with parameter value

1. Let valid be RequireObjectCoercible(value).
2. ReturnIfAbrupt(valid).
3. Return NormalCompletion(empty).

1. Let valid be RequireObjectCoercible(value).
2. ReturnIfAbrupt(valid).
3. Return the result of performing DestructuringAssignmentEvaluation for AssignmentPropertyList using value as the argument.

1. Let iterator be GetIterator(val ue).
2. ReturnIfAbrupt(iterator).
3. Return IteratorClose(iterator, NormalCompletion(empty)).

1. Let iterator be GetIterator(value).
2. ReturnIfAbrupt(iterator).
3. Let iteratorRecord be Record {[[iterator]]: iterator, [[done]]: false}.
4. Let result be the result of performing IteratorDestructuringAssignmentEvaluation of Elision with iteratorRecord as the argument.
5. If iteratorRecord.[[done]] is false, return IteratorClose(iterator, result).
6. Return result.

1. Let iterator be GetIterator(value).
2. ReturnIfAbrupt(iterator).
3. Let iteratorRecord be Record {[[iterator]]: iterator, [[done]]: false}.
4. If Elision is present, then
   1. Let status be the result of performing IteratorDestructuringAssignmentEvaluation of Elision with iteratorRecord as the argument.
   2. If status is an abrupt completion, then
      1. If iteratorRecord.[[done]] is false, return IteratorClose(iterator, status).
      2. Return Completion(status).
5. Let result be the result of performing IteratorDestructuringAssignmentEvaluation of AssignmentRestElement with iteratorRecord as the argument.
6. If iteratorRecord.[[done]] is false, return IteratorClose(iterator, result).
7. Return result.

1. Let iterator be GetIterator(value).
2. ReturnIfAbrupt(iterator).
3. Let iteratorRecord be Record {[[iterator]]: iterator, [[done]]: false}.
4. Let result be the result of performing IteratorDestructuringAssignmentEvaluation of AssignmentElementList using iteratorRecord as the argument.
5. If iteratorRecord.[[done]] is false, return IteratorClose(iterator, result).
6. Return result.

1. Let iterator be GetIterator(value).
2. ReturnIfAbrupt(iterator).
3. Let iteratorRecord be Record {[[iterator]]: iterator, [[done]]: false}.
4. Let status be the result of performing IteratorDestructuringAssignmentEvaluation of AssignmentElementList using iteratorRecord as the argument.
5. If status is an abrupt completion, then
   1. If iteratorRecord.[[done]] is false, return IteratorClose(iterator, status).
   2. Return Completion(status).
6. If Elision is present, then
   1. Let status be the result of performing IteratorDestructuringAssignmentEvaluation of Elision with iteratorRecord as the argument.
   2. If status is an abrupt completion, then
      1. If iteratorRecord.[[done]] is false, return IteratorClose(iterator, status).
      2. Return Completion(status).
7. If AssignmentRestElement is present, then
   1. Let status be the result of performing IteratorDestructuringAssignmentEvaluation of AssignmentRestElement with iteratorRecord as the argument.
8. If iteratorRecord.[[done]] is false, return IteratorClose(iterator, status).
9. Return Completion(status).

1. Let status be the result of performing DestructuringAssignmentEvaluation for AssignmentPropertyList using value as the argument.
2. ReturnIfAbrupt(status).
3. Return the result of performing DestructuringAssignmentEvaluation for AssignmentProperty using value as the argument.

1. Let P be StringValue of IdentifierReference.
2. Let lref be ResolveBinding(P).
3. ReturnIfAbrupt(P).
4. Let v be GetV(value, P).
5. ReturnIfAbrupt(v).
6. If Initializer_opt is present and v is undefined, then
   1. Let defaultValue be the result of evaluating Initializer.
   2. Let v be GetValue(defaultValue).
   3. ReturnIfAbrupt(v).
   4. If IsAnonymousFunctionDefinition(Initializer) is true, then
      1. Let hasNameProperty be HasOwnProperty(v, "name").
      2. ReturnIfAbrupt(hasNameProperty).
      3. If hasNameProperty is false, perform SetFunctionName(v, P).
7. Return PutValue(lref,v).

1. Let name be the result of evaluating PropertyName.
2. ReturnIfAbrupt(name).
3. Return the result of performing KeyedDestructuringAssignmentEvaluation of AssignmentElement with value and name as the arguments.

12.14.5.3 Runtime Semantics: IteratorDestructuringAssignmentEvaluation

with parameters iteratorRecord

1. Return the result of performing IteratorDestructuringAssignmentEvaluation of AssignmentElisionElement using iteratorRecord as the argument.

1. Let status be the result of performing IteratorDestructuringAssignmentEvaluation of AssignmentElementList using iteratorRecord as the argument.
2. ReturnIfAbrupt(status).
3. Return the result of performing IteratorDestructuringAssignmentEvaluation of AssignmentElisionElement using iteratorRecord as the argument.

1. Return the result of performing IteratorDestructuringAssignmentEvaluation of AssignmentElement with iteratorRecord as the argument.

1. Let status be the result of performing IteratorDestructuringAssignmentEvaluation of Elision with iteratorRecord as the argument.
2. ReturnIfAbrupt(status).
3. Return the result of performing IteratorDestructuringAssignmentEvaluation of AssignmentElement with iteratorRecord as the argument.

1. If iteratorRecord.[[done]] is false, then
   1. Let next be IteratorStep(iteratorRecord.[[iterator]]).
   2. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
   3. ReturnIfAbrupt(next).
   4. If next is false, set iteratorRecord.[[done]] to true.
2. Return NormalCompletion(empty).

1. Let status be the result of performing IteratorDestructuringAssignmentEvaluation of Elision with iteratorRecord as the argument.
2. ReturnIfAbrupt(status).
3. If iteratorRecord.[[done]] is false, then
   1. Let next be IteratorStep(iteratorRecord.[[iterator]]).
   2. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
   3. ReturnIfAbrupt(next).
   4. If next is false, set iteratorRecord.[[done]] to true.
4. Return NormalCompletion(empty).

AssignmentElement_[Yield] : DestructuringAssignmentTarget Initializer_opt

1. If DestructuringAssignmentTarget is neither an ObjectLiteral nor an ArrayLiteral, then
   1. Let lref be the result of evaluating DestructuringAssignmentTarget.
   2. ReturnIfAbrupt(lref).
2. If iteratorRecord.[[done]] is false, then
   1. Let next be IteratorStep(iteratorRecord.[[iterator]]).
   2. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
   3. ReturnIfAbrupt(next).
   4. If next is false, set iteratorRecord.[[done]] to true.
   5. Else
      1. Let value be IteratorValue(next).
      2. If value is an abrupt completion, set iteratorRecord.[[done]] to true.
      3. ReturnIfAbrupt(value).
3. If iteratorRecord.[[done]] is true, let value be undefined.
4. If Initializer is present and value is undefined, then
   1. Let defaultValue be the result of evaluating Initializer.
   2. Let v be GetValue(defaultValue)
   3. ReturnIfAbrupt(v).
5. Else, let v be value.
6. If DestructuringAssignmentTarget is an ObjectLiteral or an ArrayLiteral, then
   1. Let nestedAssignmentPattern be the parse of the source text corresponding to DestructuringAssignmentTarget using either AssignmentPattern or AssignmentPattern_[Yield] as the goal symbol depending upon whether this AssignmentElement has the _Yield parameter.
   2. Return the result of performing DestructuringAssignmentEvaluation of nestedAssignmentPattern with v as the argument.
7. If Initializer is present and value is undefined and IsAnonymousFunctionDefinition(Initializer) and IsIdentifierRef of DestructuringAssignmentTarget are both true, then
   1. Let hasNameProperty be HasOwnProperty(v, "name").
   2. ReturnIfAbrupt(hasNameProperty).
   3. If hasNameProperty is false, perform SetFunctionName(v, GetReferencedName(lref)).
8. Return PutValue(lref, v).

AssignmentRestElement_[Yield] : ... DestructuringAssignmentTarget

1. If DestructuringAssignmentTarget is neither an ObjectLiteral nor an ArrayLiteral, then
   1. Let lref be the result of evaluating DestructuringAssignmentTarget.
   2. ReturnIfAbrupt(lref).
2. Let A be ArrayCreate(0).
3. Let n=0;
4. Repeat while iteratorRecord.[[done]] is false,
   1. Let next be IteratorStep(iteratorRecord.[[iterator]]).
   2. If next is an abrupt completion, set iteratorRecord.[[done]] to true.
   3. ReturnIfAbrupt(next).
   4. If next is false, set iteratorRecord.[[done]] to true.
   5. else,
      1. Let nextValue be IteratorValue(next).
      2. If nextValue is an abrupt completion, set iteratorRecord.[[done]] to true.
      3. ReturnIfAbrupt(nextValue).
      4. Let status be CreateDataProperty(A, ToString(n), nextValue).
      5. Assert: status is true.
      6. Increment n by 1.
5. If DestructuringAssignmentTarget is neither an ObjectLiteral nor an ArrayLiteral, then
   1. Return PutValue(lref, A).
6. Let nestedAssignmentPattern be the parse of the source text corresponding to DestructuringAssignmentTarget using either AssignmentPattern or AssignmentPattern_[Yield] as the goal symbol depending upon whether this AssignmentElement has the _Yield parameter.
7. Return the result of performing DestructuringAssignmentEvaluation of nestedAssignmentPattern with A as the argument.