Синтаксис

Эта глава представляет грамматику для языка программирования Java.

Грамматика, представленная по частям в предыдущих главах, намного лучше для выставки, но это не хорошо подходит как основание для синтаксического анализатора. Грамматика, представленная в этой главе, является основанием для ссылочной реализации. Отметьте, что это не LL (1) грамматика, хотя во многих случаях это минимизирует необходимое, смотрят вперед.

Грамматика ниже использует следующие соглашения BNF-стиля:

[x] обозначает нуль или возникновения x.
{x} обозначает нуль или больше возникновений x.

x | y означает один из x или y.

18.1 Грамматика Языка программирования Java


Identifier:
        IDENTIFIER

QualifiedIdentifier:
        Identifier { . Identifier }

Literal:
        IntegerLiteral
        FloatingPointLiteral
        CharacterLiteral
        StringLiteral
        BooleanLiteral
        NullLiteral

Expression:
        Expression1 [AssignmentOperator Expression1]]

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

Type:
        Identifier [TypeArguments]{   .   Identifier [TypeArguments]} {[]}
        BasicType

TypeArguments:
        < TypeArgument {, TypeArgument} >

TypeArgument:
        Type
        ? [( extends |super ) Type]

StatementExpression:
        Expression

ConstantExpression:
        Expression

Expression1:
        Expression2 [Expression1Rest]

Expression1Rest:
        ?   Expression   :   Expression1

Expression2 :
        Expression3 [Expression2Rest]

Expression2Rest:
        {InfixOp Expression3}
        Expression3 instanceof Type

InfixOp:
        ||
        &&
        |
        ^
        &
        ==
        !=
        <
        >
        <=
        >=
        <<
        >>
        >>>
        +
        -
        *
        /
        %

Expression3:
        PrefixOp Expression3
        (   Expression | Type   )   Expression3
        Primary {Selector} {PostfixOp}

Primary:
        ParExpression
        NonWildcardTypeArguments (ExplicitGenericInvocationSuffix | this
Arguments)
  this [Arguments]
  super SuperSuffix
        Literal
  new Creator
        Identifier { . Identifier }[ IdentifierSuffix]
        BasicType {[]} .class
   void.class

IdentifierSuffix:
        [ ( ] {[]} .   class | Expression ])
        Arguments
        .   ( class | ExplicitGenericInvocation | this | super Arguments | new
[NonWildcardTypeArguments] InnerCreator )

ExplicitGenericInvocation:
        NonWildcardTypeArguments ExplicitGenericInvocationSuffix

NonWildcardTypeArguments:
        < TypeList >


ExplicitGenericInvocationSuffix:
     super SuperSuffix
        Identifier Arguments


PrefixOp:
        ++
        --
        !
        ~
        +
        -

PostfixOp:
        ++
        --

Selector: Selector:
        . Identifier [Arguments]
        . ExplicitGenericInvocation
        . this
   . super SuperSuffix
        . new [NonWildcardTypeArguments] InnerCreator
        [ Expression ]

SuperSuffix:
        Arguments
        . Identifier [Arguments]

BasicType:
  byte
  short
  char
  int
  long
  float
  double
  boolean

Arguments:
        ( [Expression { , Expression }] )

Creator:
        [NonWildcardTypeArguments] CreatedName ( ArrayCreatorRest  |
ClassCreatorRest )

CreatedName:
        Identifier [NonWildcardTypeArguments] {. Identifier
[NonWildcardTypeArguments]}

InnerCreator:
        Identifier ClassCreatorRest

ArrayCreatorRest:
        [ ( ] {[]} ArrayInitializer | Expression ] {[ Expression ]} {[]} )

ClassCreatorRest:
         Arguments [ClassBody]

ArrayInitializer:
        { [VariableInitializer {, VariableInitializer} [,]] }

VariableInitializer:
        ArrayInitializer
        Expression

ParExpression:
        ( Expression )

Block:
        { BlockStatements }

BlockStatements:
        { BlockStatement }

BlockStatement :
        LocalVariableDeclarationStatement
        ClassOrInterfaceDeclaration
        [Identifier :] Statement

LocalVariableDeclarationStatement:
        [final] Type VariableDeclarators   ;

Statement:
        Block
        assert Expression [ : Expression] ;
     if ParExpression Statement [else Statement]
     for ( ForControl ) Statement
     while ParExpression Statement
     do Statement while ParExpression   ;
     try Block ( Catches | [Catches] finally Block )
     switch ParExpression { SwitchBlockStatementGroups }
     synchronized ParExpression Block
     return [Expression] ;
     throw Expression   ;
     break [Identifier]
     continue [Identifier]
        ;
        StatementExpression ;
        Identifier   :   Statement

Catches:
        CatchClause {CatchClause}

CatchClause:
     catch ( FormalParameter ) Block

SwitchBlockStatementGroups:
        { SwitchBlockStatementGroup }

SwitchBlockStatementGroup:
        SwitchLabel BlockStatements

SwitchLabel:
     case ConstantExpression   :
        case EnumConstantName :
        default   :

MoreStatementExpressions:
        { , StatementExpression }

ForControl:
        ForVarControl
        ForInit;   [Expression]   ; [ForUpdate]

ForVarControl
        [final] [Annotations] Type Identifier ForVarControlRest

Annotations:
        Annotation [Annotations]

Annotation:
        @ TypeName [( [Identifier =] ElementValue)]

ElementValue:
        ConditionalExpression
        Annotation
        ElementValueArrayInitializer

ConditionalExpression:
        Expression2 Expression1Rest

    ElementValueArrayInitializer:
        { [ElementValues] [,] }

    ElementValues:
        ElementValue [ElementValues]

ForVarControlRest:
        VariableDeclaratorsRest;   [Expression]   ;   [ForUpdate]
        : Expression

ForInit:
        StatementExpression Expressions

Modifier:
  Annotation
  public
  protected
  private
  static
  abstract
  final
  native
  synchronized
  transient
  volatile
        strictfp

VariableDeclarators:
        VariableDeclarator { ,   VariableDeclarator }

VariableDeclaratorsRest:
        VariableDeclaratorRest { ,   VariableDeclarator }

ConstantDeclaratorsRest:
        ConstantDeclaratorRest { ,   ConstantDeclarator }

VariableDeclarator:
        Identifier VariableDeclaratorRest

ConstantDeclarator:
        Identifier ConstantDeclaratorRest

VariableDeclaratorRest:
        {[]} [  =   VariableInitializer]

ConstantDeclaratorRest:
        {[]} =   VariableInitializer

VariableDeclaratorId:
        Identifier {[]}

CompilationUnit:
        [[Annotations] package QualifiedIdentifier   ;  ] {ImportDeclaration}
{TypeDeclaration}

ImportDeclaration:
     import [ static] Identifier {   .   Identifier } [   .     *   ] ;

TypeDeclaration:
        ClassOrInterfaceDeclaration
        ;

ClassOrInterfaceDeclaration:
        {Modifier} (ClassDeclaration | InterfaceDeclaration)

ClassDeclaration:
        NormalClassDeclaration
        EnumDeclaration

NormalClassDeclaration:
     class Identifier [TypeParameters] [extends Type] [implements TypeList]
ClassBody

TypeParameters:
        < TypeParameter {, TypeParameter} >

TypeParameter:
        Identifier [extends Bound]

Bound:
         Type {& Type}


EnumDeclaration:
        enum Identifier [implements TypeList] EnumBody

EnumBody:
        { [EnumConstants] [,] [EnumBodyDeclarations] }

EnumConstants:
        EnumConstant
        EnumConstants , EnumConstant

EnumConstant:
        Annotations Identifier [Arguments] [ClassBody]

EnumBodyDeclarations:
        ; {ClassBodyDeclaration}

InterfaceDeclaration:
        NormalInterfaceDeclaration
        AnnotationTypeDeclaration

NormalInterfaceDeclaration:
     interface Identifier [ TypeParameters] [extends TypeList] InterfaceBody

TypeList:
        Type {  ,   Type}

AnnotationTypeDeclaration:
        @ interface Identifier AnnotationTypeBody

    AnnotationTypeBody:
        { [AnnotationTypeElementDeclarations] }

    AnnotationTypeElementDeclarations:
        AnnotationTypeElementDeclaration
        AnnotationTypeElementDeclarations AnnotationTypeElementDeclaration

AnnotationTypeElementDeclaration:
        {Modifier} AnnotationTypeElementRest

AnnotationTypeElementRest:
         Type Identifier AnnotationMethodOrConstantRest;
        ClassDeclaration
        InterfaceDeclaration
        EnumDeclaration
        AnnotationTypeDeclaration

        AnnotationMethodOrConstantRest:
        AnnotationMethodRest
        AnnotationConstantRest

AnnotationMethodRest:
        ( ) [DefaultValue]

AnnotationConstantRest:
        VariableDeclarators


    DefaultValue:
        default ElementValue

ClassBody:
        { {ClassBodyDeclaration} }

InterfaceBody:
        { {InterfaceBodyDeclaration} }

ClassBodyDeclaration:
        ;
        [static] Block
        {Modifier} MemberDecl

MemberDecl:
        GenericMethodOrConstructorDecl
        MethodOrFieldDecl
        void Identifier VoidMethodDeclaratorRest
        Identifier ConstructorDeclaratorRest
        InterfaceDeclaration
        ClassDeclaration

GenericMethodOrConstructorDecl:
        TypeParameters GenericMethodOrConstructorRest

GenericMethodOrConstructorRest:
        (Type | void) Identifier MethodDeclaratorRest
        Identifier ConstructorDeclaratorRest

MethodOrFieldDecl:
        Type Identifier MethodOrFieldRest

MethodOrFieldRest:
        VariableDeclaratorRest
        MethodDeclaratorRest

InterfaceBodyDeclaration:
        ;
        {Modifier} InterfaceMemberDecl

InterfaceMemberDecl:
        InterfaceMethodOrFieldDecl
        InterfaceGenericMethodDecl
        void Identifier VoidInterfaceMethodDeclaratorRest
        InterfaceDeclaration
        ClassDeclaration

InterfaceMethodOrFieldDecl:
        Type Identifier InterfaceMethodOrFieldRest

InterfaceMethodOrFieldRest:
        ConstantDeclaratorsRest ;
        InterfaceMethodDeclaratorRest

MethodDeclaratorRest:
        FormalParameters {[]} [throws QualifiedIdentifierList] ( MethodBody |   ;
)

VoidMethodDeclaratorRest:
        FormalParameters [throws QualifiedIdentifierList] ( MethodBody |   ;  )

InterfaceMethodDeclaratorRest:
        FormalParameters {[]} [throws QualifiedIdentifierList]   ;

InterfaceGenericMethodDecl:
        TypeParameters (Type | void) Identifier InterfaceMethodDeclaratorRest

VoidInterfaceMethodDeclaratorRest:
        FormalParameters [throws QualifiedIdentifierList]   ;

ConstructorDeclaratorRest:
        FormalParameters [throws QualifiedIdentifierList] MethodBody

QualifiedIdentifierList:
        QualifiedIdentifier {  ,   QualifiedIdentifier}

FormalParameters:
        ( [FormalParameterDecls] )

FormalParameterDecls:
        [final] [Annotations] Type FormalParameterDeclsRest]

FormalParameterDeclsRest:
        VariableDeclaratorId [ , FormalParameterDecls]
        ... VariableDeclaratorId

MethodBody:
        Block

EnumConstantName:
        Identifier

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