TypeScript

          Grammar

This appendix contains a summary of the grammar found in the main document. As described in section 2.1, the TypeScript grammar is a superset of the grammar defined in the ECMAScript Language Specification (specifically, the ECMA-262 Standard, 5^th Edition) and this appendix lists only productions that are new or modified from the ECMAScript grammar.

1.1    Types

TypeParameters:
<   TypeParameterList   >

TypeParameterList:
TypeParameter
TypeParameterList   ,   TypeParameter

TypeParameter:
Identifier   Constraint_opt

Constraint:
extends   Type

Type:
PredefinedType
TypeReference
TypeQuery
TypeLiteral

PredefinedType:
any
number
boolean
string
void

TypeReference:
TypeName   TypeArguments_opt

TypeName:
Identifier
ModuleName   .   Identifier

ModuleName:
Identifier
ModuleName   .   Identifier

TypeArguments:
<   TypeArgumentList   >

TypeArgumentList:
TypeArgument
TypeArgumentList   ,   TypeArgument

TypeArgument:
Type

TypeQuery:
typeof   TypeQueryExpression

TypeQueryExpression:
Identifier
TypeQueryExpression   .   IdentifierName

TypeLiteral:
ObjectType
ArrayType
FunctionType
ConstructorType

ArrayType:
PredefinedType   [   ]
TypeReference   [   ]
ObjectType   [   ]
ArrayType   [   ]

FunctionType:
TypeParameters_opt   (   ParameterList_opt   )   =>   Type

ConstructorType:
new   TypeParameters_opt   (   ParameterList_opt   )   =>   Type

ObjectType:
{   TypeBody_opt   }

TypeBody:
TypeMemberList   ;_opt

TypeMemberList:
TypeMember
TypeMemberList   ;   TypeMember

TypeMember:
PropertySignature
CallSignature
ConstructSignature
IndexSignature
MethodSignature

PropertySignature:
PropertyName   ?_opt   TypeAnnotation_opt

PropertyName:
IdentifierName
StringLiteral
NumericLiteral

CallSignature:
TypeParameters_opt   (   ParameterList_opt   )   TypeAnnotation_opt

ParameterList:
RequiredParameterList
OptionalParameterList
RestParameter
RequiredParameterList   ,   OptionalParameterList
RequiredParameterList   ,   RestParameter
OptionalParameterList   ,   RestParameter
RequiredParameterList   ,   OptionalParameterList   ,   RestParameter

RequiredParameterList:
RequiredParameter
RequiredParameterList   ,   RequiredParameter

RequiredParameter:
PublicOrPrivate_opt   Identifier   TypeAnnotation_opt
Identifier   :   StringLiteral

PublicOrPrivate:
public
private

OptionalParameterList:
OptionalParameter
OptionalParameterList   ,   OptionalParameter

OptionalParameter:
PublicOrPrivate_opt   Identifier   ?   TypeAnnotation_opt
PublicOrPrivate_opt   Identifier   TypeAnnotation_opt   Initialiser

RestParameter:
...   Identifier   TypeAnnotation_opt

ConstructSignature:
new   TypeParameters_opt   (   ParameterList_opt   )   TypeAnnotation_opt

IndexSignature:
[   Identifier   :   string   ]   TypeAnnotation
[   Identifier   :   number   ]   TypeAnnotation

MethodSignature:
PropertyName   ?_opt   CallSignature

1.2    Expressions

PropertyAssignment:  ( Modified )
PropertyName   :   AssignmentExpression
PropertyName   CallSignature   {   FunctionBody   }
GetAccessor
SetAccessor

GetAccessor:
get   PropertyName   (   )   TypeAnnotation_opt   {   FunctionBody   }

SetAccessor:
set   PropertyName   (   Identifier   TypeAnnotation_opt   )   {   FunctionBody   }

CallExpression:  ( Modified )
…
super   (   ArgumentList_opt   )
super   .   IdentifierName

FunctionExpression:  ( Modified )
function   Identifier_opt   CallSignature   {   FunctionBody   }

AssignmentExpression:  ( Modified )
…
ArrowFunctionExpression

ArrowFunctionExpression:
ArrowFormalParameters   =>   Block
ArrowFormalParameters   =>   AssignmentExpression

ArrowFormalParameters:
CallSignature
Identifier

Arguments:  ( Modified )
TypeArguments_opt   (   ArgumentList_opt   )

UnaryExpression:  ( Modified )
…
<   Type   >   UnaryExpression

1.3    Statements

VariableDeclaration:  ( Modified )
Identifier   TypeAnnotation_opt   Initialiser_opt

VariableDeclarationNoIn:  ( Modified )
Identifier   TypeAnnotation_opt   InitialiserNoIn_opt

TypeAnnotation:
:   Type

1.4    Functions

FunctionDeclaration:  ( Modified )
FunctionOverloads_opt   FunctionImplementation

FunctionOverloads:
FunctionOverload
FunctionOverloads   FunctionOverload

FunctionOverload:
function   Identifier   CallSignature   ;

FunctionImplementation:
function   Identifier   CallSignature   {   FunctionBody   }

1.5    Interfaces

InterfaceDeclaration:
interface   Identifier   TypeParameters_opt   InterfaceExtendsClause_opt   ObjectType

InterfaceExtendsClause:
extends   ClassOrInterfaceTypeList

ClassOrInterfaceTypeList:
ClassOrInterfaceType
ClassOrInterfaceTypeList   ,   ClassOrInterfaceType

ClassOrInterfaceType:
TypeReference

1.6    Classes

ClassDeclaration:
class   Identifier   TypeParameters_opt   ClassHeritage   {   ClassBody   }

ClassHeritage:
ClassExtendsClause_opt   ImplementsClause_opt

ClassExtendsClause:
extends    ClassType

ClassType:
TypeReference

ImplementsClause:
implements   ClassOrInterfaceTypeList

ClassBody:
ClassElements_opt

ClassElements:
ClassElement
ClassElements   ClassElement

ClassElement:
ConstructorDeclaration
MemberDeclaration
IndexSignature

ConstructorDeclaration:
ConstructorOverloads_opt   ConstructorImplementation

ConstructorOverloads:
ConstructorOverload
ConstructorOverloads   ConstructorOverload

ConstructorOverload:
constructor   (   ParameterList_opt   )   ;

ConstructorImplementation:
constructor   (   ParameterList_opt   )   {   FunctionBody   }

MemberDeclaration:
MemberVariableDeclaration
MemberFunctionDeclaration
MemberAccessorDeclaration

MemberVariableDeclaration:
PublicOrPrivate_opt   static_opt   PropertyName   TypeAnnotation_opt   Initialiser_opt   ;

MemberFunctionDeclaration:
MemberFunctionOverloads_opt   MemberFunctionImplementation

MemberFunctionOverloads:
MemberFunctionOverload
MemberFunctionOverloads   MemberFunctionOverload

MemberFunctionOverload:
PublicOrPrivate_opt   static_opt   PropertyName   CallSignature   ;

MemberFunctionImplementation:
PublicOrPrivate_opt   static_opt   PropertyName   CallSignature   {   FunctionBody   }

MemberAccessorDeclaration:
PublicOrPrivate_opt   static_opt   GetAccessor
PublicOrPrivate_opt   static_opt   SetAccessor

1.7    Enums

EnumDeclaration:
enum   Identifier   {   EnumBody_opt   }

EnumBody:
ConstantEnumMemberList   ,_opt
ConstantEnumMemberList   ,   ComputedEnumMemberList   ,_opt
ComputedEnumMemberList   ,_opt

ConstantEnumMemberList:
ConstantEnumMember
ConstantEnumMemberList   ,   ConstantEnumMember

ConstantEnumMember:
PropertyName
PropertyName   =   IntegerLiteral

IntegerLiteral:
SignedInteger
HexIntegerLiteral

ComputedEnumMemberList:
ComputedEnumMember
ComputedEnumMemberList   ,   ComputedEnumMember

ComputedEnumMember:
PropertyName   =   AssignmentExpression

1.8    Internal Modules

ModuleDeclaration:
module   IdentifierPath   {   ModuleBody   }

IdentifierPath:
Identifier
IdentifierPath   .   Identifier

ModuleBody:
ModuleElements_opt

ModuleElements:
ModuleElement
ModuleElements   ModuleElement

ModuleElement:
Statement
export_opt   VariableDeclaration
export_opt   FunctionDeclaration
export_opt   ClassDeclaration
export_opt   InterfaceDeclaration
export_opt   EnumDeclaration
export_opt   ModuleDeclaration
export_opt   ImportDeclaration

ImportDeclaration:
import   Identifier   =   EntityName   ;

EntityName:
Identifier
ModuleName   .   Identifier

1.9    Programs and External Modules

SourceFile:
ImplementationSourceFile
DeclarationSourceFile

ImplementationSourceFile:
ImplementationElements_opt

ImplementationElements:
ImplementationElement
ImplementationElements   ImplementationElement

ImplementationElement:
ModuleElement
ExportAssignment
export_opt   ExternalImportDeclaration
export_opt   AmbientDeclaration

DeclarationSourceFile:
DeclarationElements_opt

DeclarationElements:
DeclarationElement
DeclarationElements   DeclarationElement

DeclarationElement:
ExportAssignment
export_opt   InterfaceDeclaration
export_opt   ImportDeclaration
export_opt   ExternalImportDeclaration
export_opt   AmbientDeclaration

ExternalImportDeclaration:
import   Identifier   =   ExternalModuleReference   ;

ExternalModuleReference:
require   (   StringLiteral   )

ExportAssignment:
export   =   Identifier   ;

1.10 Ambients

AmbientDeclaration:
declare   AmbientVariableDeclaration
declare   AmbientFunctionDeclaration
declare   AmbientClassDeclaration
declare   AmbientEnumDeclaration
declare   AmbientModuleDeclaration
declare   AmbientExternalModuleDeclaration

AmbientVariableDeclaration:
var   Identifier    TypeAnnotation_opt   ;

AmbientFunctionDeclaration:
function   Identifier   CallSignature   ;

AmbientClassDeclaration:
class   Identifier   TypeParameters_opt   ClassHeritage   {   AmbientClassBody   }

AmbientClassBody:
AmbientClassBodyElements_opt

AmbientClassBodyElements:
AmbientClassBodyElement
AmbientClassBodyElements   AmbientClassBodyElement

AmbientClassBodyElement:
AmbientConstructorDeclaration
AmbientMemberDeclaration
IndexSignature

AmbientConstructorDeclaration:
constructor   (   ParameterList_opt   )   ;

AmbientMemberDeclaration:
PublicOrPrivate_opt   static_opt   PropertyName   TypeAnnotation_opt   ;
PublicOrPrivate_opt   static_opt   PropertyName   CallSignature   ;

AmbientEnumDeclaration:
enum   Identifier   {   AmbientEnumBody_opt   }

AmbientEnumBody:
AmbientEnumMemberList   ,_opt

AmbientEnumMemberList:
AmbientEnumMember
AmbientEnumMemberList   ,   AmbientEnumMember

AmbientEnumMember:
PropertyName
PropertyName   =   IntegerLiteral

AmbientModuleDeclaration:
module   IdentifierPath   {   AmbientModuleBody   }

AmbientModuleBody:
AmbientModuleElements_opt

AmbientModuleElements:
AmbientModuleElement
AmbientModuleElements   AmbientModuleElement

AmbientModuleElement:
export_opt   AmbientVariableDeclaration
export_opt   AmbientFunctionDeclaration
export_opt   AmbientClassDeclaration
export_opt   InterfaceDeclaration
export_opt   AmbientEnumDeclaration
export_opt   AmbientModuleDeclaration
export_opt   ImportDeclaration

AmbientExternalModuleDeclaration:
module   StringLiteral   {    AmbientExternalModuleBody   }

AmbientExternalModuleBody:
AmbientExternalModuleElements_opt

AmbientExternalModuleElements:
AmbientExternalModuleElement
AmbientExternalModuleElements   AmbientExternalModuleElement

AmbientExternalModuleElement:
AmbientModuleElement
ExportAssignment
export_opt   ExternalImportDeclaration

TypeScript Language Specification (converted to HTML pages by @Bartvds)

Version 0.9.1

August 2013

Microsoft is making this Specification available under the Open Web Foundation Final Specification Agreement  Version 1.0 ('OWF 1.0') as of October 1, 2012. The OWF 1.0 is available at  http://www.openwebfoundation.org/legal/the-owf-1-0-agreements/owfa-1-0.

TypeScript is a trademark of Microsoft Corporation.