ECMAScript 2020 Language Specification

1 Grammar

SourceCharacter::any Unicode code point InputElementDiv::WhiteSpace LineTerminator Comment CommonToken DivPunctuator RightBracePunctuator InputElementRegExp::WhiteSpace LineTerminator Comment CommonToken RightBracePunctuator RegularExpressionLiteral InputElementRegExpOrTemplateTail::WhiteSpace LineTerminator Comment CommonToken RegularExpressionLiteral TemplateSubstitutionTail InputElementTemplateTail::WhiteSpace LineTerminator Comment CommonToken DivPunctuator TemplateSubstitutionTail WhiteSpace::<TAB> <VT> <FF> <SP> <NBSP> <ZWNBSP> <USP> LineTerminator::<LF> <CR> <LS> <PS> LineTerminatorSequence::<LF> <CR>[lookahead ≠ <LF>] <LS> <PS> <CR><LF> Comment::MultiLineComment SingleLineComment MultiLineComment::/*MultiLineCommentCharsopt*/ MultiLineCommentChars::MultiLineNotAsteriskCharMultiLineCommentCharsopt *PostAsteriskCommentCharsopt PostAsteriskCommentChars::MultiLineNotForwardSlashOrAsteriskCharMultiLineCommentCharsopt *PostAsteriskCommentCharsopt MultiLineNotAsteriskChar::SourceCharacterbut not * MultiLineNotForwardSlashOrAsteriskChar::SourceCharacterbut not one of / or * SingleLineComment:://SingleLineCommentCharsopt SingleLineCommentChars::SingleLineCommentCharSingleLineCommentCharsopt SingleLineCommentChar::SourceCharacterbut not LineTerminator CommonToken::IdentifierName Punctuator NumericLiteral StringLiteral Template IdentifierName::IdentifierStart IdentifierNameIdentifierPart IdentifierStart::UnicodeIDStart $ _ \UnicodeEscapeSequence IdentifierPart::UnicodeIDContinue $ \UnicodeEscapeSequence <ZWNJ> <ZWJ> UnicodeIDStart::any Unicode code point with the Unicode property “ID_Start” UnicodeIDContinue::any Unicode code point with the Unicode property “ID_Continue” ReservedWord::one ofawaitbreakcasecatchclassconstcontinuedebuggerdefaultdeletedoelseenumexportextendsfalsefinallyforfunctionifimportininstanceofnewnullreturnsuperswitchthisthrowtruetrytypeofvarvoidwhilewithyield Punctuator::OptionalChainingPunctuator OtherPunctuator OptionalChainingPunctuator::?.[lookahead ∉ DecimalDigit] OtherPunctuator::one of{()[]....;,<><=>===!====!==+-*%**++--<<>>>>>&|^!~&&||???:=+=-=*=%=**=<<=>>=>>>=&=|=^==> DivPunctuator::/ /= RightBracePunctuator::} NullLiteral::null BooleanLiteral::true false NumericLiteral::DecimalLiteral DecimalBigIntegerLiteral NonDecimalIntegerLiteral NonDecimalIntegerLiteralBigIntLiteralSuffix DecimalBigIntegerLiteral::0BigIntLiteralSuffix NonZeroDigitDecimalDigitsoptBigIntLiteralSuffix NonDecimalIntegerLiteral::BinaryIntegerLiteral OctalIntegerLiteral HexIntegerLiteral BigIntLiteralSuffix::n DecimalLiteral::DecimalIntegerLiteral.DecimalDigitsoptExponentPartopt .DecimalDigitsExponentPartopt DecimalIntegerLiteralExponentPartopt DecimalIntegerLiteral::0 NonZeroDigitDecimalDigitsopt DecimalDigits::DecimalDigit DecimalDigitsDecimalDigit DecimalDigit::one of0123456789 NonZeroDigit::one of123456789 ExponentPart::ExponentIndicatorSignedInteger ExponentIndicator::one ofeE SignedInteger::DecimalDigits +DecimalDigits -DecimalDigits BinaryIntegerLiteral::0bBinaryDigits 0BBinaryDigits BinaryDigits::BinaryDigit BinaryDigitsBinaryDigit BinaryDigit::one of01 OctalIntegerLiteral::0oOctalDigits 0OOctalDigits OctalDigits::OctalDigit OctalDigitsOctalDigit OctalDigit::one of01234567 HexIntegerLiteral::0xHexDigits 0XHexDigits HexDigits::HexDigit HexDigitsHexDigit HexDigit::one of0123456789abcdefABCDEF StringLiteral::"DoubleStringCharactersopt" 'SingleStringCharactersopt' DoubleStringCharacters::DoubleStringCharacterDoubleStringCharactersopt SingleStringCharacters::SingleStringCharacterSingleStringCharactersopt DoubleStringCharacter::SourceCharacterbut not one of " or \ or LineTerminator <LS> <PS> \EscapeSequence LineContinuation SingleStringCharacter::SourceCharacterbut not one of ' or \ or LineTerminator <LS> <PS> \EscapeSequence LineContinuation LineContinuation::\LineTerminatorSequence EscapeSequence::CharacterEscapeSequence 0[lookahead ∉ DecimalDigit] HexEscapeSequence UnicodeEscapeSequence CharacterEscapeSequence::SingleEscapeCharacter NonEscapeCharacter SingleEscapeCharacter::one of'"\bfnrtv NonEscapeCharacter::SourceCharacterbut not one of EscapeCharacter or LineTerminator EscapeCharacter::SingleEscapeCharacter DecimalDigit x u HexEscapeSequence::xHexDigitHexDigit UnicodeEscapeSequence::uHex4Digits u{CodePoint} Hex4Digits::HexDigitHexDigitHexDigitHexDigit RegularExpressionLiteral::/RegularExpressionBody/RegularExpressionFlags RegularExpressionBody::RegularExpressionFirstCharRegularExpressionChars RegularExpressionChars::[empty] RegularExpressionCharsRegularExpressionChar RegularExpressionFirstChar::RegularExpressionNonTerminatorbut not one of * or \ or / or [ RegularExpressionBackslashSequence RegularExpressionClass RegularExpressionChar::RegularExpressionNonTerminatorbut not one of \ or / or [ RegularExpressionBackslashSequence RegularExpressionClass RegularExpressionBackslashSequence::\RegularExpressionNonTerminator RegularExpressionNonTerminator::SourceCharacterbut not LineTerminator RegularExpressionClass::[RegularExpressionClassChars] RegularExpressionClassChars::[empty] RegularExpressionClassCharsRegularExpressionClassChar RegularExpressionClassChar::RegularExpressionNonTerminatorbut not one of ] or \ RegularExpressionBackslashSequence RegularExpressionFlags::[empty] RegularExpressionFlagsIdentifierPart Template::NoSubstitutionTemplate TemplateHead NoSubstitutionTemplate::`TemplateCharactersopt` TemplateHead::`TemplateCharactersopt${ TemplateSubstitutionTail::TemplateMiddle TemplateTail TemplateMiddle::}TemplateCharactersopt${ TemplateTail::}TemplateCharactersopt` TemplateCharacters::TemplateCharacterTemplateCharactersopt TemplateCharacter::$[lookahead ≠ {] \EscapeSequence \NotEscapeSequence LineContinuation LineTerminatorSequence SourceCharacterbut not one of ` or \ or $ or LineTerminator NotEscapeSequence::0DecimalDigit DecimalDigitbut not 0 x[lookahead ∉ HexDigit] xHexDigit[lookahead ∉ HexDigit] u[lookahead ∉ HexDigit][lookahead ≠ {] uHexDigit[lookahead ∉ HexDigit] uHexDigitHexDigit[lookahead ∉ HexDigit] uHexDigitHexDigitHexDigit[lookahead ∉ HexDigit] u{[lookahead ∉ HexDigit] u{NotCodePoint[lookahead ∉ HexDigit] u{CodePoint[lookahead ∉ HexDigit][lookahead ≠ }] NotCodePoint::HexDigitsbut only if MV of HexDigits > 0x10FFFF CodePoint::HexDigitsbut only if MV of HexDigits < 0x10FFFF IdentifierReference[Yield, Await]:Identifier [~Yield]yield [~Await]await BindingIdentifier[Yield, Await]:Identifier yield await LabelIdentifier[Yield, Await]:Identifier [~Yield]yield [~Await]await Identifier:IdentifierNamebut not ReservedWord PrimaryExpression[Yield, Await]:this IdentifierReference[?Yield, ?Await] Literal ArrayLiteral[?Yield, ?Await] ObjectLiteral[?Yield, ?Await] FunctionExpression ClassExpression[?Yield, ?Await] GeneratorExpression AsyncFunctionExpression AsyncGeneratorExpression RegularExpressionLiteral TemplateLiteral[?Yield, ?Await, ~Tagged] CoverParenthesizedExpressionAndArrowParameterList[?Yield, ?Await] CoverParenthesizedExpressionAndArrowParameterList[Yield, Await]:(Expression[+In, ?Yield, ?Await]) (Expression[+In, ?Yield, ?Await],) () (...BindingIdentifier[?Yield, ?Await]) (...BindingPattern[?Yield, ?Await]) (Expression[+In, ?Yield, ?Await],...BindingIdentifier[?Yield, ?Await]) (Expression[+In, ?Yield, ?Await],...BindingPattern[?Yield, ?Await]) ParenthesizedExpression[Yield, Await]:(Expression[+In, ?Yield, ?Await]) Literal:NullLiteral BooleanLiteral NumericLiteral StringLiteral ArrayLiteral[Yield, Await]:[Elisionopt] [ElementList[?Yield, ?Await]] [ElementList[?Yield, ?Await],Elisionopt] ElementList[Yield, Await]:ElisionoptAssignmentExpression[+In, ?Yield, ?Await] ElisionoptSpreadElement[?Yield, ?Await] ElementList[?Yield, ?Await],ElisionoptAssignmentExpression[+In, ?Yield, ?Await] ElementList[?Yield, ?Await],ElisionoptSpreadElement[?Yield, ?Await] Elision:, Elision, SpreadElement[Yield, Await]:...AssignmentExpression[+In, ?Yield, ?Await] ObjectLiteral[Yield, Await]:{} {PropertyDefinitionList[?Yield, ?Await]} {PropertyDefinitionList[?Yield, ?Await],} PropertyDefinitionList[Yield, Await]:PropertyDefinition[?Yield, ?Await] PropertyDefinitionList[?Yield, ?Await],PropertyDefinition[?Yield, ?Await] PropertyDefinition[Yield, Await]:IdentifierReference[?Yield, ?Await] CoverInitializedName[?Yield, ?Await] PropertyName[?Yield, ?Await]:AssignmentExpression[+In, ?Yield, ?Await] MethodDefinition[?Yield, ?Await] ...AssignmentExpression[+In, ?Yield, ?Await] PropertyName[Yield, Await]:LiteralPropertyName ComputedPropertyName[?Yield, ?Await] LiteralPropertyName:IdentifierName StringLiteral NumericLiteral ComputedPropertyName[Yield, Await]:[AssignmentExpression[+In, ?Yield, ?Await]] CoverInitializedName[Yield, Await]:IdentifierReference[?Yield, ?Await]Initializer[+In, ?Yield, ?Await] Initializer[In, Yield, Await]:=AssignmentExpression[?In, ?Yield, ?Await] TemplateLiteral[Yield, Await, Tagged]:NoSubstitutionTemplate SubstitutionTemplate[?Yield, ?Await, ?Tagged] SubstitutionTemplate[Yield, Await, Tagged]:TemplateHeadExpression[+In, ?Yield, ?Await]TemplateSpans[?Yield, ?Await, ?Tagged] TemplateSpans[Yield, Await, Tagged]:TemplateTail TemplateMiddleList[?Yield, ?Await, ?Tagged]TemplateTail TemplateMiddleList[Yield, Await, Tagged]:TemplateMiddleExpression[+In, ?Yield, ?Await] TemplateMiddleList[?Yield, ?Await, ?Tagged]TemplateMiddleExpression[+In, ?Yield, ?Await] MemberExpression[Yield, Await]:PrimaryExpression[?Yield, ?Await] MemberExpression[?Yield, ?Await][Expression[+In, ?Yield, ?Await]] MemberExpression[?Yield, ?Await].IdentifierName MemberExpression[?Yield, ?Await]TemplateLiteral[?Yield, ?Await, +Tagged] SuperProperty[?Yield, ?Await] MetaProperty newMemberExpression[?Yield, ?Await]Arguments[?Yield, ?Await] SuperProperty[Yield, Await]:super[Expression[+In, ?Yield, ?Await]] super.IdentifierName MetaProperty:NewTarget ImportMeta NewTarget:new.target ImportMeta:import.meta NewExpression[Yield, Await]:MemberExpression[?Yield, ?Await] newNewExpression[?Yield, ?Await] CallExpression[Yield, Await]:CoverCallExpressionAndAsyncArrowHead[?Yield, ?Await] SuperCall[?Yield, ?Await] ImportCall[?Yield, ?Await] CallExpression[?Yield, ?Await]Arguments[?Yield, ?Await] CallExpression[?Yield, ?Await][Expression[+In, ?Yield, ?Await]] CallExpression[?Yield, ?Await].IdentifierName CallExpression[?Yield, ?Await]TemplateLiteral[?Yield, ?Await, +Tagged] SuperCall[Yield, Await]:superArguments[?Yield, ?Await] ImportCall[Yield, Await]:import(AssignmentExpression[+In, ?Yield, ?Await]) Arguments[Yield, Await]:() (ArgumentList[?Yield, ?Await]) (ArgumentList[?Yield, ?Await],) ArgumentList[Yield, Await]:AssignmentExpression[+In, ?Yield, ?Await] ...AssignmentExpression[+In, ?Yield, ?Await] ArgumentList[?Yield, ?Await],AssignmentExpression[+In, ?Yield, ?Await] ArgumentList[?Yield, ?Await],...AssignmentExpression[+In, ?Yield, ?Await] OptionalExpression[Yield, Await]:MemberExpression[?Yield, ?Await]OptionalChain[?Yield, ?Await] CallExpression[?Yield, ?Await]OptionalChain[?Yield, ?Await] OptionalExpression[?Yield, ?Await]OptionalChain[?Yield, ?Await] OptionalChain[Yield, Await]:?.Arguments[?Yield, ?Await] ?.[Expression[+In, ?Yield, ?Await]] ?.IdentifierName ?.TemplateLiteral[?Yield, ?Await, +Tagged] OptionalChain[?Yield, ?Await]Arguments[?Yield, ?Await] OptionalChain[?Yield, ?Await][Expression[+In, ?Yield, ?Await]] OptionalChain[?Yield, ?Await].IdentifierName OptionalChain[?Yield, ?Await]TemplateLiteral[?Yield, ?Await, +Tagged] LeftHandSideExpression[Yield, Await]:NewExpression[?Yield, ?Await] CallExpression[?Yield, ?Await] OptionalExpression[?Yield, ?Await] CallMemberExpression[Yield, Await]:MemberExpression[?Yield, ?Await]Arguments[?Yield, ?Await] UpdateExpression[Yield, Await]:LeftHandSideExpression[?Yield, ?Await] LeftHandSideExpression[?Yield, ?Await][no LineTerminator here]++ LeftHandSideExpression[?Yield, ?Await][no LineTerminator here]-- ++UnaryExpression[?Yield, ?Await] --UnaryExpression[?Yield, ?Await] UnaryExpression[Yield, Await]:UpdateExpression[?Yield, ?Await] deleteUnaryExpression[?Yield, ?Await] voidUnaryExpression[?Yield, ?Await] typeofUnaryExpression[?Yield, ?Await] +UnaryExpression[?Yield, ?Await] -UnaryExpression[?Yield, ?Await] ~UnaryExpression[?Yield, ?Await] !UnaryExpression[?Yield, ?Await] [+Await]AwaitExpression[?Yield] ExponentiationExpression[Yield, Await]:UnaryExpression[?Yield, ?Await] UpdateExpression[?Yield, ?Await]**ExponentiationExpression[?Yield, ?Await] MultiplicativeExpression[Yield, Await]:ExponentiationExpression[?Yield, ?Await] MultiplicativeExpression[?Yield, ?Await]MultiplicativeOperatorExponentiationExpression[?Yield, ?Await] MultiplicativeOperator:one of*/% AdditiveExpression[Yield, Await]:MultiplicativeExpression[?Yield, ?Await] AdditiveExpression[?Yield, ?Await]+MultiplicativeExpression[?Yield, ?Await] AdditiveExpression[?Yield, ?Await]-MultiplicativeExpression[?Yield, ?Await] ShiftExpression[Yield, Await]:AdditiveExpression[?Yield, ?Await] ShiftExpression[?Yield, ?Await]<AdditiveExpression[?Yield, ?Await] ShiftExpression[?Yield, ?Await]>AdditiveExpression[?Yield, ?Await] ShiftExpression[?Yield, ?Await]>AdditiveExpression[?Yield, ?Await] RelationalExpression[In, Yield, Await]:ShiftExpression[?Yield, ?Await] RelationalExpression[?In, ?Yield, ?Await]<ShiftExpression[?Yield, ?Await] RelationalExpression[?In, ?Yield, ?Await]>ShiftExpression[?Yield, ?Await] RelationalExpression[?In, ?Yield, ?Await]<=ShiftExpression[?Yield, ?Await] RelationalExpression[?In, ?Yield, ?Await]>=ShiftExpression[?Yield, ?Await] RelationalExpression[?In, ?Yield, ?Await]instanceofShiftExpression[?Yield, ?Await] [+In]RelationalExpression[+In, ?Yield, ?Await]inShiftExpression[?Yield, ?Await] EqualityExpression[In, Yield, Await]:RelationalExpression[?In, ?Yield, ?Await] EqualityExpression[?In, ?Yield, ?Await]==RelationalExpression[?In, ?Yield, ?Await] EqualityExpression[?In, ?Yield, ?Await]!=RelationalExpression[?In, ?Yield, ?Await] EqualityExpression[?In, ?Yield, ?Await]===RelationalExpression[?In, ?Yield, ?Await] EqualityExpression[?In, ?Yield, ?Await]!==RelationalExpression[?In, ?Yield, ?Await] BitwiseANDExpression[In, Yield, Await]:EqualityExpression[?In, ?Yield, ?Await] BitwiseANDExpression[?In, ?Yield, ?Await]&EqualityExpression[?In, ?Yield, ?Await] BitwiseXORExpression[In, Yield, Await]:BitwiseANDExpression[?In, ?Yield, ?Await] BitwiseXORExpression[?In, ?Yield, ?Await]^BitwiseANDExpression[?In, ?Yield, ?Await] BitwiseORExpression[In, Yield, Await]:BitwiseXORExpression[?In, ?Yield, ?Await] BitwiseORExpression[?In, ?Yield, ?Await]|BitwiseXORExpression[?In, ?Yield, ?Await] LogicalANDExpression[In, Yield, Await]:BitwiseORExpression[?In, ?Yield, ?Await] LogicalANDExpression[?In, ?Yield, ?Await]&BitwiseORExpression[?In, ?Yield, ?Await] LogicalORExpression[In, Yield, Await]:LogicalANDExpression[?In, ?Yield, ?Await] LogicalORExpression[?In, ?Yield, ?Await]||LogicalANDExpression[?In, ?Yield, ?Await] CoalesceExpression[In, Yield, Await]:CoalesceExpressionHead[?In, ?Yield, ?Await]??BitwiseORExpression[?In, ?Yield, ?Await] CoalesceExpressionHead[In, Yield, Await]:CoalesceExpression[?In, ?Yield, ?Await] BitwiseORExpression[?In, ?Yield, ?Await] ShortCircuitExpression[In, Yield, Await]:LogicalORExpression[?In, ?Yield, ?Await] CoalesceExpression[?In, ?Yield, ?Await] ConditionalExpression[In, Yield, Await]:ShortCircuitExpression[?In, ?Yield, ?Await] ShortCircuitExpression[?In, ?Yield, ?Await]?AssignmentExpression[+In, ?Yield, ?Await]:AssignmentExpression[?In, ?Yield, ?Await] AssignmentExpression[In, Yield, Await]:ConditionalExpression[?In, ?Yield, ?Await] [+Yield]YieldExpression[?In, ?Await] ArrowFunction[?In, ?Yield, ?Await] AsyncArrowFunction[?In, ?Yield, ?Await] LeftHandSideExpression[?Yield, ?Await]=AssignmentExpression[?In, ?Yield, ?Await] LeftHandSideExpression[?Yield, ?Await]AssignmentOperatorAssignmentExpression[?In, ?Yield, ?Await] AssignmentOperator:one of*=/=%=+=-=<<=>>=>>>=&=^=|=**= AssignmentPattern[Yield, Await]:ObjectAssignmentPattern[?Yield, ?Await] ArrayAssignmentPattern[?Yield, ?Await] ObjectAssignmentPattern[Yield, Await]:{} {AssignmentRestProperty[?Yield, ?Await]} {AssignmentPropertyList[?Yield, ?Await]} {AssignmentPropertyList[?Yield, ?Await],AssignmentRestProperty[?Yield, ?Await]opt} ArrayAssignmentPattern[Yield, Await]:[ElisionoptAssignmentRestElement[?Yield, ?Await]opt] [AssignmentElementList[?Yield, ?Await]] [AssignmentElementList[?Yield, ?Await],ElisionoptAssignmentRestElement[?Yield, ?Await]opt] AssignmentRestProperty[Yield, Await]:...DestructuringAssignmentTarget[?Yield, ?Await] AssignmentPropertyList[Yield, Await]:AssignmentProperty[?Yield, ?Await] AssignmentPropertyList[?Yield, ?Await],AssignmentProperty[?Yield, ?Await] AssignmentElementList[Yield, Await]:AssignmentElisionElement[?Yield, ?Await] AssignmentElementList[?Yield, ?Await],AssignmentElisionElement[?Yield, ?Await] AssignmentElisionElement[Yield, Await]:ElisionoptAssignmentElement[?Yield, ?Await] AssignmentProperty[Yield, Await]:IdentifierReference[?Yield, ?Await]Initializer[+In, ?Yield, ?Await]opt PropertyName[?Yield, ?Await]:AssignmentElement[?Yield, ?Await] AssignmentElement[Yield, Await]:DestructuringAssignmentTarget[?Yield, ?Await]Initializer[+In, ?Yield, ?Await]opt AssignmentRestElement[Yield, Await]:...DestructuringAssignmentTarget[?Yield, ?Await] DestructuringAssignmentTarget[Yield, Await]:LeftHandSideExpression[?Yield, ?Await] Expression[In, Yield, Await]:AssignmentExpression[?In, ?Yield, ?Await] Expression[?In, ?Yield, ?Await],AssignmentExpression[?In, ?Yield, ?Await] Statement[Yield, Await, Return]:BlockStatement[?Yield, ?Await, ?Return] VariableStatement[?Yield, ?Await] EmptyStatement ExpressionStatement[?Yield, ?Await] IfStatement[?Yield, ?Await, ?Return] BreakableStatement[?Yield, ?Await, ?Return] ContinueStatement[?Yield, ?Await] BreakStatement[?Yield, ?Await] [+Return]ReturnStatement[?Yield, ?Await] WithStatement[?Yield, ?Await, ?Return] LabelledStatement[?Yield, ?Await, ?Return] ThrowStatement[?Yield, ?Await] TryStatement[?Yield, ?Await, ?Return] DebuggerStatement Declaration[Yield, Await]:HoistableDeclaration[?Yield, ?Await, ~Default] ClassDeclaration[?Yield, ?Await, ~Default] LexicalDeclaration[+In, ?Yield, ?Await] HoistableDeclaration[Yield, Await, Default]:FunctionDeclaration[?Yield, ?Await, ?Default] GeneratorDeclaration[?Yield, ?Await, ?Default] AsyncFunctionDeclaration[?Yield, ?Await, ?Default] AsyncGeneratorDeclaration[?Yield, ?Await, ?Default] BreakableStatement[Yield, Await, Return]:IterationStatement[?Yield, ?Await, ?Return] SwitchStatement[?Yield, ?Await, ?Return] BlockStatement[Yield, Await, Return]:Block[?Yield, ?Await, ?Return] Block[Yield, Await, Return]:{StatementList[?Yield, ?Await, ?Return]opt} StatementList[Yield, Await, Return]:StatementListItem[?Yield, ?Await, ?Return] StatementList[?Yield, ?Await, ?Return]StatementListItem[?Yield, ?Await, ?Return] StatementListItem[Yield, Await, Return]:Statement[?Yield, ?Await, ?Return] Declaration[?Yield, ?Await] LexicalDeclaration[In, Yield, Await]:LetOrConstBindingList[?In, ?Yield, ?Await]; LetOrConst:let const BindingList[In, Yield, Await]:LexicalBinding[?In, ?Yield, ?Await] BindingList[?In, ?Yield, ?Await],LexicalBinding[?In, ?Yield, ?Await] LexicalBinding[In, Yield, Await]:BindingIdentifier[?Yield, ?Await]Initializer[?In, ?Yield, ?Await]opt BindingPattern[?Yield, ?Await]Initializer[?In, ?Yield, ?Await] VariableStatement[Yield, Await]:varVariableDeclarationList[+In, ?Yield, ?Await]; VariableDeclarationList[In, Yield, Await]:VariableDeclaration[?In, ?Yield, ?Await] VariableDeclarationList[?In, ?Yield, ?Await],VariableDeclaration[?In, ?Yield, ?Await] VariableDeclaration[In, Yield, Await]:BindingIdentifier[?Yield, ?Await]Initializer[?In, ?Yield, ?Await]opt BindingPattern[?Yield, ?Await]Initializer[?In, ?Yield, ?Await] BindingPattern[Yield, Await]:ObjectBindingPattern[?Yield, ?Await] ArrayBindingPattern[?Yield, ?Await] ObjectBindingPattern[Yield, Await]:{} {BindingRestProperty[?Yield, ?Await]} {BindingPropertyList[?Yield, ?Await]} {BindingPropertyList[?Yield, ?Await],BindingRestProperty[?Yield, ?Await]opt} ArrayBindingPattern[Yield, Await]:[ElisionoptBindingRestElement[?Yield, ?Await]opt] [BindingElementList[?Yield, ?Await]] [BindingElementList[?Yield, ?Await],ElisionoptBindingRestElement[?Yield, ?Await]opt] BindingRestProperty[Yield, Await]:...BindingIdentifier[?Yield, ?Await] BindingPropertyList[Yield, Await]:BindingProperty[?Yield, ?Await] BindingPropertyList[?Yield, ?Await],BindingProperty[?Yield, ?Await] BindingElementList[Yield, Await]:BindingElisionElement[?Yield, ?Await] BindingElementList[?Yield, ?Await],BindingElisionElement[?Yield, ?Await] BindingElisionElement[Yield, Await]:ElisionoptBindingElement[?Yield, ?Await] BindingProperty[Yield, Await]:SingleNameBinding[?Yield, ?Await] PropertyName[?Yield, ?Await]:BindingElement[?Yield, ?Await] BindingElement[Yield, Await]:SingleNameBinding[?Yield, ?Await] BindingPattern[?Yield, ?Await]Initializer[+In, ?Yield, ?Await]opt SingleNameBinding[Yield, Await]:BindingIdentifier[?Yield, ?Await]Initializer[+In, ?Yield, ?Await]opt BindingRestElement[Yield, Await]:...BindingIdentifier[?Yield, ?Await] ...BindingPattern[?Yield, ?Await] EmptyStatement:; ExpressionStatement[Yield, Await]:[lookahead ∉ { {, function, async [no LineTerminator here] function, class, let [ }]Expression[+In, ?Yield, ?Await]; IfStatement[Yield, Await, Return]:if(Expression[+In, ?Yield, ?Await])Statement[?Yield, ?Await, ?Return]elseStatement[?Yield, ?Await, ?Return] if(Expression[+In, ?Yield, ?Await])Statement[?Yield, ?Await, ?Return] IterationStatement[Yield, Await, Return]:doStatement[?Yield, ?Await, ?Return]while(Expression[+In, ?Yield, ?Await]); while(Expression[+In, ?Yield, ?Await])Statement[?Yield, ?Await, ?Return] for([lookahead ≠ let []Expression[~In, ?Yield, ?Await]opt;Expression[+In, ?Yield, ?Await]opt;Expression[+In, ?Yield, ?Await]opt)Statement[?Yield, ?Await, ?Return] for(varVariableDeclarationList[~In, ?Yield, ?Await];Expression[+In, ?Yield, ?Await]opt;Expression[+In, ?Yield, ?Await]opt)Statement[?Yield, ?Await, ?Return] for(LexicalDeclaration[~In, ?Yield, ?Await]Expression[+In, ?Yield, ?Await]opt;Expression[+In, ?Yield, ?Await]opt)Statement[?Yield, ?Await, ?Return] for([lookahead ≠ let []LeftHandSideExpression[?Yield, ?Await]inExpression[+In, ?Yield, ?Await])Statement[?Yield, ?Await, ?Return] for(varForBinding[?Yield, ?Await]inExpression[+In, ?Yield, ?Await])Statement[?Yield, ?Await, ?Return] for(ForDeclaration[?Yield, ?Await]inExpression[+In, ?Yield, ?Await])Statement[?Yield, ?Await, ?Return] for([lookahead ≠ let]LeftHandSideExpression[?Yield, ?Await]ofAssignmentExpression[+In, ?Yield, ?Await])Statement[?Yield, ?Await, ?Return] for(varForBinding[?Yield, ?Await]ofAssignmentExpression[+In, ?Yield, ?Await])Statement[?Yield, ?Await, ?Return] for(ForDeclaration[?Yield, ?Await]ofAssignmentExpression[+In, ?Yield, ?Await])Statement[?Yield, ?Await, ?Return] [+Await]forawait([lookahead ≠ let]LeftHandSideExpression[?Yield, ?Await]ofAssignmentExpression[+In, ?Yield, ?Await])Statement[?Yield, ?Await, ?Return] [+Await]forawait(varForBinding[?Yield, ?Await]ofAssignmentExpression[+In, ?Yield, ?Await])Statement[?Yield, ?Await, ?Return] [+Await]forawait(ForDeclaration[?Yield, ?Await]ofAssignmentExpression[+In, ?Yield, ?Await])Statement[?Yield, ?Await, ?Return] ForDeclaration[Yield, Await]:LetOrConstForBinding[?Yield, ?Await] ForBinding[Yield, Await]:BindingIdentifier[?Yield, ?Await] BindingPattern[?Yield, ?Await] ContinueStatement[Yield, Await]:continue; continue[no LineTerminator here]LabelIdentifier[?Yield, ?Await]; BreakStatement[Yield, Await]:break; break[no LineTerminator here]LabelIdentifier[?Yield, ?Await]; ReturnStatement[Yield, Await]:return; return[no LineTerminator here]Expression[+In, ?Yield, ?Await]; WithStatement[Yield, Await, Return]:with(Expression[+In, ?Yield, ?Await])Statement[?Yield, ?Await, ?Return] SwitchStatement[Yield, Await, Return]:switch(Expression[+In, ?Yield, ?Await])CaseBlock[?Yield, ?Await, ?Return] CaseBlock[Yield, Await, Return]:{CaseClauses[?Yield, ?Await, ?Return]opt} {CaseClauses[?Yield, ?Await, ?Return]optDefaultClause[?Yield, ?Await, ?Return]CaseClauses[?Yield, ?Await, ?Return]opt} CaseClauses[Yield, Await, Return]:CaseClause[?Yield, ?Await, ?Return] CaseClauses[?Yield, ?Await, ?Return]CaseClause[?Yield, ?Await, ?Return] CaseClause[Yield, Await, Return]:caseExpression[+In, ?Yield, ?Await]:StatementList[?Yield, ?Await, ?Return]opt DefaultClause[Yield, Await, Return]:default:StatementList[?Yield, ?Await, ?Return]opt LabelledStatement[Yield, Await, Return]:LabelIdentifier[?Yield, ?Await]:LabelledItem[?Yield, ?Await, ?Return] LabelledItem[Yield, Await, Return]:Statement[?Yield, ?Await, ?Return] FunctionDeclaration[?Yield, ?Await, ~Default] ThrowStatement[Yield, Await]:throw[no LineTerminator here]Expression[+In, ?Yield, ?Await]; TryStatement[Yield, Await, Return]:tryBlock[?Yield, ?Await, ?Return]Catch[?Yield, ?Await, ?Return] tryBlock[?Yield, ?Await, ?Return]Finally[?Yield, ?Await, ?Return] tryBlock[?Yield, ?Await, ?Return]Catch[?Yield, ?Await, ?Return]Finally[?Yield, ?Await, ?Return] Catch[Yield, Await, Return]:catch(CatchParameter[?Yield, ?Await])Block[?Yield, ?Await, ?Return] catchBlock[?Yield, ?Await, ?Return] Finally[Yield, Await, Return]:finallyBlock[?Yield, ?Await, ?Return] CatchParameter[Yield, Await]:BindingIdentifier[?Yield, ?Await] BindingPattern[?Yield, ?Await] DebuggerStatement:debugger; FunctionDeclaration[Yield, Await, Default]:functionBindingIdentifier[?Yield, ?Await](FormalParameters[~Yield, ~Await]){FunctionBody[~Yield, ~Await]} [+Default]function(FormalParameters[~Yield, ~Await]){FunctionBody[~Yield, ~Await]} FunctionExpression:functionBindingIdentifier[~Yield, ~Await]opt(FormalParameters[~Yield, ~Await]){FunctionBody[~Yield, ~Await]} UniqueFormalParameters[Yield, Await]:FormalParameters[?Yield, ?Await] FormalParameters[Yield, Await]:[empty] FunctionRestParameter[?Yield, ?Await] FormalParameterList[?Yield, ?Await] FormalParameterList[?Yield, ?Await], FormalParameterList[?Yield, ?Await],FunctionRestParameter[?Yield, ?Await] FormalParameterList[Yield, Await]:FormalParameter[?Yield, ?Await] FormalParameterList[?Yield, ?Await],FormalParameter[?Yield, ?Await] FunctionRestParameter[Yield, Await]:BindingRestElement[?Yield, ?Await] FormalParameter[Yield, Await]:BindingElement[?Yield, ?Await] FunctionBody[Yield, Await]:FunctionStatementList[?Yield, ?Await] FunctionStatementList[Yield, Await]:StatementList[?Yield, ?Await, +Return]opt ArrowFunction[In, Yield, Await]:ArrowParameters[?Yield, ?Await][no LineTerminator here]=>ConciseBody[?In] ArrowParameters[Yield, Await]:BindingIdentifier[?Yield, ?Await] CoverParenthesizedExpressionAndArrowParameterList[?Yield, ?Await] ConciseBody[In]:[lookahead ≠ {]ExpressionBody[?In, ~Await] {FunctionBody[~Yield, ~Await]} ExpressionBody[In, Await]:AssignmentExpression[?In, ~Yield, ?Await] ArrowFormalParameters[Yield, Await]:(UniqueFormalParameters[?Yield, ?Await]) MethodDefinition[Yield, Await]:PropertyName[?Yield, ?Await](UniqueFormalParameters[~Yield, ~Await]){FunctionBody[~Yield, ~Await]} GeneratorMethod[?Yield, ?Await] AsyncMethod[?Yield, ?Await] AsyncGeneratorMethod[?Yield, ?Await] getPropertyName[?Yield, ?Await](){FunctionBody[~Yield, ~Await]} setPropertyName[?Yield, ?Await](PropertySetParameterList){FunctionBody[~Yield, ~Await]} PropertySetParameterList:FormalParameter[~Yield, ~Await] GeneratorMethod[Yield, Await]:*PropertyName[?Yield, ?Await](UniqueFormalParameters[+Yield, ~Await]){GeneratorBody} GeneratorDeclaration[Yield, Await, Default]:function*BindingIdentifier[?Yield, ?Await](FormalParameters[+Yield, ~Await]){GeneratorBody} [+Default]function*(FormalParameters[+Yield, ~Await]){GeneratorBody} GeneratorExpression:function*BindingIdentifier[+Yield, ~Await]opt(FormalParameters[+Yield, ~Await]){GeneratorBody} GeneratorBody:FunctionBody[+Yield, ~Await] YieldExpression[In, Await]:yield yield[no LineTerminator here]AssignmentExpression[?In, +Yield, ?Await] yield[no LineTerminator here]*AssignmentExpression[?In, +Yield, ?Await] AsyncGeneratorMethod[Yield, Await]:async[no LineTerminator here]*PropertyName[?Yield, ?Await](UniqueFormalParameters[+Yield, +Await]){AsyncGeneratorBody} AsyncGeneratorDeclaration[Yield, Await, Default]:async[no LineTerminator here]function*BindingIdentifier[?Yield, ?Await](FormalParameters[+Yield, +Await]){AsyncGeneratorBody} [+Default]async[no LineTerminator here]function*(FormalParameters[+Yield, +Await]){AsyncGeneratorBody} AsyncGeneratorExpression:async[no LineTerminator here]function*BindingIdentifier[+Yield, +Await]opt(FormalParameters[+Yield, +Await]){AsyncGeneratorBody} AsyncGeneratorBody:FunctionBody[+Yield, +Await] ClassDeclaration[Yield, Await, Default]:classBindingIdentifier[?Yield, ?Await]ClassTail[?Yield, ?Await] [+Default]classClassTail[?Yield, ?Await] ClassExpression[Yield, Await]:classBindingIdentifier[?Yield, ?Await]optClassTail[?Yield, ?Await] ClassTail[Yield, Await]:ClassHeritage[?Yield, ?Await]opt{ClassBody[?Yield, ?Await]opt} ClassHeritage[Yield, Await]:extendsLeftHandSideExpression[?Yield, ?Await] ClassBody[Yield, Await]:ClassElementList[?Yield, ?Await] ClassElementList[Yield, Await]:ClassElement[?Yield, ?Await] ClassElementList[?Yield, ?Await]ClassElement[?Yield, ?Await] ClassElement[Yield, Await]:MethodDefinition[?Yield, ?Await] staticMethodDefinition[?Yield, ?Await] ; AsyncFunctionDeclaration[Yield, Await, Default]:async[no LineTerminator here]functionBindingIdentifier[?Yield, ?Await](FormalParameters[~Yield, +Await]){AsyncFunctionBody} [+Default]async[no LineTerminator here]function(FormalParameters[~Yield, +Await]){AsyncFunctionBody} AsyncFunctionExpression:async[no LineTerminator here]function(FormalParameters[~Yield, +Await]){AsyncFunctionBody} async[no LineTerminator here]functionBindingIdentifier[~Yield, +Await](FormalParameters[~Yield, +Await]){AsyncFunctionBody} AsyncMethod[Yield, Await]:async[no LineTerminator here]PropertyName[?Yield, ?Await](UniqueFormalParameters[~Yield, +Await]){AsyncFunctionBody} AsyncFunctionBody:FunctionBody[~Yield, +Await] AwaitExpression[Yield]:awaitUnaryExpression[?Yield, +Await] AsyncArrowFunction[In, Yield, Await]:async[no LineTerminator here]AsyncArrowBindingIdentifier[?Yield][no LineTerminator here]=>AsyncConciseBody[?In] CoverCallExpressionAndAsyncArrowHead[?Yield, ?Await][no LineTerminator here]=>AsyncConciseBody[?In] AsyncConciseBody[In]:[lookahead ≠ {]ExpressionBody[?In, +Await] {AsyncFunctionBody} AsyncArrowBindingIdentifier[Yield]:BindingIdentifier[?Yield, +Await] CoverCallExpressionAndAsyncArrowHead[Yield, Await]:MemberExpression[?Yield, ?Await]Arguments[?Yield, ?Await] AsyncArrowHead:async[no LineTerminator here]ArrowFormalParameters[~Yield, +Await] Script:ScriptBodyopt ScriptBody:StatementList[~Yield, ~Await, ~Return] Module:ModuleBodyopt ModuleBody:ModuleItemList ModuleItemList:ModuleItem ModuleItemListModuleItem ModuleItem:ImportDeclaration ExportDeclaration StatementListItem[~Yield, ~Await, ~Return] ImportDeclaration:importImportClauseFromClause; importModuleSpecifier; ImportClause:ImportedDefaultBinding NameSpaceImport NamedImports ImportedDefaultBinding,NameSpaceImport ImportedDefaultBinding,NamedImports ImportedDefaultBinding:ImportedBinding NameSpaceImport:*asImportedBinding NamedImports:{} {ImportsList} {ImportsList,} FromClause:fromModuleSpecifier ImportsList:ImportSpecifier ImportsList,ImportSpecifier ImportSpecifier:ImportedBinding IdentifierNameasImportedBinding ModuleSpecifier:StringLiteral ImportedBinding:BindingIdentifier[~Yield, ~Await] ExportDeclaration:exportExportFromClauseFromClause; exportNamedExports; exportVariableStatement[~Yield, ~Await] exportDeclaration[~Yield, ~Await] exportdefaultHoistableDeclaration[~Yield, ~Await, +Default] exportdefaultClassDeclaration[~Yield, ~Await, +Default] exportdefault[lookahead ∉ { function, async [no LineTerminator here] function, class }]AssignmentExpression[+In, ~Yield, ~Await]; ExportFromClause:* *asIdentifierName NamedExports NamedExports:{} {ExportsList} {ExportsList,} ExportsList:ExportSpecifier ExportsList,ExportSpecifier ExportSpecifier:IdentifierName IdentifierNameasIdentifierName uri:::uriCharactersopt uriCharacters:::uriCharacteruriCharactersopt uriCharacter:::uriReserved uriUnescaped uriEscaped uriReserved:::one of;/?:@&=+$, uriUnescaped:::uriAlpha DecimalDigit uriMark uriEscaped:::%HexDigitHexDigit uriAlpha:::one ofabcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ uriMark:::one of-_.!~*'() NativeFunction:functionPropertyName[~Yield, ~Await]opt(FormalParameters[~Yield, ~Await]){[nativecode]} Pattern[U, N]::Disjunction[?U, ?N] Disjunction[U, N]::Alternative[?U, ?N] Alternative[?U, ?N]|Disjunction[?U, ?N] Alternative[U, N]::[empty] Alternative[?U, ?N]Term[?U, ?N] Term[U, N]::Assertion[?U, ?N] Atom[?U, ?N] Atom[?U, ?N]Quantifier Assertion[U, N]::^ $ \b \B (?=Disjunction[?U, ?N]) (?!Disjunction[?U, ?N]) (?<=Disjunction[?U, ?N]) (?<!Disjunction[?U, ?N]) Quantifier::QuantifierPrefix QuantifierPrefix? QuantifierPrefix::* + ? {DecimalDigits} {DecimalDigits,} {DecimalDigits,DecimalDigits} Atom[U, N]::PatternCharacter . \AtomEscape[?U, ?N] CharacterClass[?U] (GroupSpecifier[?U]Disjunction[?U, ?N]) (?:Disjunction[?U, ?N]) SyntaxCharacter::one of^$\.*+?()[]{}| PatternCharacter::SourceCharacterbut not SyntaxCharacter AtomEscape[U, N]::DecimalEscape CharacterClassEscape[?U] CharacterEscape[?U] [+N]kGroupName[?U] CharacterEscape[U]::ControlEscape cControlLetter 0[lookahead ∉ DecimalDigit] HexEscapeSequence RegExpUnicodeEscapeSequence[?U] IdentityEscape[?U] ControlEscape::one offnrtv ControlLetter::one ofabcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ GroupSpecifier[U]::[empty] ?GroupName[?U] GroupName[U]::<RegExpIdentifierName[?U]> RegExpIdentifierName[U]::RegExpIdentifierStart[?U] RegExpIdentifierName[?U]RegExpIdentifierPart[?U] RegExpIdentifierStart[U]::UnicodeIDStart $ _ \RegExpUnicodeEscapeSequence[+U] [~U]UnicodeLeadSurrogateUnicodeTrailSurrogate RegExpIdentifierPart[U]::UnicodeIDContinue $ \RegExpUnicodeEscapeSequence[+U] [~U]UnicodeLeadSurrogateUnicodeTrailSurrogate <ZWNJ> <ZWJ> RegExpUnicodeEscapeSequence[U]::[+U]uLeadSurrogate\uTrailSurrogate [+U]uLeadSurrogate [+U]uTrailSurrogate [+U]uNonSurrogate [~U]uHex4Digits [+U]u{CodePoint} UnicodeLeadSurrogate::any Unicode code point in the inclusive range 0xD800 to 0xDBFF UnicodeTrailSurrogate::any Unicode code point in the inclusive range 0xDC00 to 0xDFFF LeadSurrogate::Hex4Digitsbut only if the SV of Hex4Digits is in the inclusive range 0xD800 to 0xDBFF TrailSurrogate::Hex4Digitsbut only if the SV of Hex4Digits is in the inclusive range 0xDC00 to 0xDFFF NonSurrogate::Hex4Digitsbut only if the SV of Hex4Digits is not in the inclusive range 0xD800 to 0xDFFF IdentityEscape[U]::[+U]SyntaxCharacter [+U]/ [~U]SourceCharacterbut not UnicodeIDContinue DecimalEscape::NonZeroDigitDecimalDigitsopt[lookahead ∉ DecimalDigit] CharacterClassEscape[U]::d D s S w W [+U]p{UnicodePropertyValueExpression} [+U]P{UnicodePropertyValueExpression} UnicodePropertyValueExpression::UnicodePropertyName=UnicodePropertyValue LoneUnicodePropertyNameOrValue UnicodePropertyName::UnicodePropertyNameCharacters UnicodePropertyNameCharacters::UnicodePropertyNameCharacterUnicodePropertyNameCharactersopt UnicodePropertyValue::UnicodePropertyValueCharacters LoneUnicodePropertyNameOrValue::UnicodePropertyValueCharacters UnicodePropertyValueCharacters::UnicodePropertyValueCharacterUnicodePropertyValueCharactersopt UnicodePropertyValueCharacter::UnicodePropertyNameCharacter DecimalDigit UnicodePropertyNameCharacter::ControlLetter _ CharacterClass[U]::[[lookahead ≠ ^]ClassRanges[?U]] [^ClassRanges[?U]] ClassRanges[U]::[empty] NonemptyClassRanges[?U] NonemptyClassRanges[U]::ClassAtom[?U] ClassAtom[?U]NonemptyClassRangesNoDash[?U] ClassAtom[?U]-ClassAtom[?U]ClassRanges[?U] NonemptyClassRangesNoDash[U]::ClassAtom[?U] ClassAtomNoDash[?U]NonemptyClassRangesNoDash[?U] ClassAtomNoDash[?U]-ClassAtom[?U]ClassRanges[?U] ClassAtom[U]::- ClassAtomNoDash[?U] ClassAtomNoDash[U]::SourceCharacterbut not one of \ or ] or - \ClassEscape[?U] ClassEscape[U]::b [+U]- CharacterClassEscape[?U] CharacterEscape[?U]

A Copyright & Software License

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Software License

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