snapshot.esgrammar

Script :
  StatementList?

Module :
  StatementList?

StatementList :
  Statement
  StatementList Statement

Statement :
  Block
  ExpressionStatement
  EmptyStatement
  CompoundStatementKeyword Arguments
  `else`
  `do`
  `for` AwaitKeyword? `(` ForHead `)`
  `case` Expression[+In] `:`
  `default` `:`
  `continue` `;`
  `continue` Identifier `;`
  `break` `;`
  `break` Identifier `;`
  `return` `;`
  `return` Expression[+In] `;`
  Identifier `:` Statement
  `throw` Expression[+In] `;`
  `try`
  `catch` Arguments
  `catch` Block
  `finally`
  `debugger` `;`
  Declaration
  `import` ImportClause FromClause? `;`
  `export` `*` FromClause `;`
  `export` ExportClause FromClause? `;`
  `export` Declaration
  `export` `default` Statement

CompoundStatementKeyword ::
  `if`
  `while`
  `switch`
  `with`

ForHead :
  [lookahead <! {`let`, `async`}] Expression[~In]? `;` Expression[+In]? `;` Expression[+In]?
  LocalDeclaration[~In] `;` Expression[+In]? `;` Expression[+In]?
  [lookahead <! {`let`, `async`} ] PostfixExpression InOrOf Expression[+In]
  VarLetOrConst PrimaryExpression InOrOf Expression[+In]

InOrOf ::
  `in`
  `of`

Declaration :
  LocalDeclaration[+In] `;`
  FunctionDeclaration
  ClassDeclaration


AwaitKeyword :
  `await`

AsyncKeyword :
  `async`

Sparkle :
  `*`

Block :
  `{` StatementList? `}`

EmptyStatement :
  `;`

ExpressionStatement :
  [lookahead <! {`{`, `function`, `async`, `class`, `let`}] Expression[+In] `;`

LocalDeclaration[In] :
  VarLetOrConst BindingList[?In]

VarLetOrConst :
  `var`
  `let`
  `const`

BindingList[In] :
  Binding[?In]
  BindingList[?In] `,` Binding[?In]

Binding[In] :
  PrimaryExpression
  PrimaryExpression `=` AssignmentExpression[?In]

FunctionDeclaration :
  `function` Sparkle? Identifier Arguments Block
  `async` `function` Sparkle? Identifier Arguments Block

FunctionExpression :
  `function` Sparkle? Identifier? Arguments Block
  `async` `function` Sparkle? Identifier? Arguments Block

ClassDeclaration :
  `class` Identifier ClassHeritage? `{` ClassElementList? `}`

ClassExpression :
  `class` Identifier? ClassHeritage? `{` ClassElementList? `}`

ClassHeritage :
  `extends` PostfixExpression

Expression[In] :
  AssignmentExpression[?In]
  Expression[?In] `,` AssignmentExpression[?In]

AssignmentExpression[In] :
  ConditionalExpression[?In]
  `yield`
  `yield` AssignmentExpression[?In]
  `yield` `*` AssignmentExpression[?In]
  PostfixExpression `=>` ConciseBody[?In]
  `async` Identifier `=>` ConciseBody[?In]
  PostfixExpression AssignmentOperator AssignmentExpression[?In]

ConciseBody[In] :
  [lookahead != `{`] AssignmentExpression[?In]
  Block

AssignmentOperator :
  `=`
  CompoundAssignmentOperator

CompoundAssignmentOperator ::
  `*=`
  `/=`
  `%=`
  `+=`
  `-=`
  `<<=`
  `>>=`
  `>>>=`
  `&=`
  `^=`
  `|=`
  `**=`

ConditionalExpression[In] :
  BinaryExpression[?In]
  BinaryExpression[?In] `?` AssignmentExpression[+In] `:` AssignmentExpression[?In]

BinaryExpression[In] :
  UnaryExpression
  BinaryExpression[?In] BinaryOperator[?In] UnaryExpression

BinaryOperator[In] :
  DedicatedBinaryOperator
  [+In] `in`
  `+`
  `-`
  `*`

DedicatedBinaryOperator ::
  `||`
  `&&`
  `|`
  `^`
  `&`
  `==`
  `!=`
  `===`
  `!==`
  `<`
  `>`
  `<=`
  `>=`
  `instanceof`
  `<<`
  `>>`
  `>>>`
  `/`
  `%`
  `**`

UnaryExpression :
  PostfixExpression
  UnaryOperator UnaryExpression

UnaryOperator :
  DedicatedUnaryOperator
  `+`
  `-`
  `await`
  `++`
  `--`
  `new`
  `...`

DedicatedUnaryOperator ::
  `delete`
  `void`
  `typeof`
  `~`
  `!`

Arguments :
  `(` Expression[+In] `)`

PostfixExpression :
  PrimaryExpression
  PostfixExpression `++`
  PostfixExpression `--`
  PostfixExpression Arguments
  PostfixExpression `[` Expression[+In] `]`
  PostfixExpression `.` IdentifierName
  PostfixExpression TemplateLiteral
  `new` `.` `target`

PrimaryExpression :
  DedicatedPrimaryExpressionToken
  Identifier
  Arguments
  `[` Expression[+In] `]`
  `{` `}`
  `{` PropertyDefinitionList `}`
  `{` PropertyDefinitionList `,` `}`
  FunctionExpression
  ClassExpression

DedicatedPrimaryExpressionToken ::
  `null`
  `true`
  `false`
  NumericLiteral
  StringLiteral
  RegularExpressionLiteral
  TemplateLiteral
  `this`
  `super`

TemplateLiteral :
  NoSubstitutionTemplate
  TemplateHead Expression[+In] TemplateMiddleList? TemplateTail

TemplateMiddleList :
  TemplateMiddle Expression[+In]
  TemplateMiddleList TemplateMiddle Expression[+In]

PropertyDefinitionList :
  PropertyDefinition
  PropertyDefinitionList `,` PropertyDefinition

PropertyDefinition :
  PropertyName
  PropertyName `=` AssignmentExpression[+In]
  PropertyName `:` AssignmentExpression[+In]
  MethodDefinition
  `...` AssignmentExpression[+In]

PropertyName :
  `[` AssignmentExpression[+In] `]`
  IdentifierName
  StringLiteral
  NumericLiteral

MethodDefinition :
  MethodPrefix? PropertyName Arguments Block

MethodPrefix :
  `get`
  `set`
  `async`
  `async` `*`
  `*`

ClassElementList :
  ClassElement
  ClassElementList ClassElement

ClassElement :
  MethodDefinition
  `static` MethodDefinition
  `;`

ImportClause :
  Identifier
  ImportExportSet
  `*` `as` Identifier
  Identifier `,` ImportExportSet

ImportExportSet :
  `{` `}`
  `{` ImportExportList `}`
  `{` ImportExportList `,` `}`

ImportExportList :
  IdentifierName
  ImportExportList `,` IdentifierName
  ImportExportList `as` IdentifierName

ExportClause :
  ImportExportSet

FromClause :
  `from` StringLiteral