\appendix
\chapter{Scala Syntax Summary}
The lexical syntax of Scala is given by the following grammar in EBNF
form.
\begin{lstlisting}
upper ::= `A' | $\ldots$ | `Z' | `$\Dollar$' | `_'
lower ::= `a' | $\ldots$ | `z'
letter ::= upper | lower
digit ::= `0' | $\ldots$ | `9'
special ::= $\mbox{\rm\em ``all other characters except parentheses ([{}]) and periods''}$
op ::= special {special}
varid ::= lower {letter | digit} [`_' [id]]
id ::= upper {letter | digit} [`_' [id]]
| varid
| op
| `\'stringLit
intLit ::= $\mbox{\rm\em ``as in Java''}$
floatLit ::= $\mbox{\rm\em ``as in Java''}$
charLit ::= $\mbox{\rm\em ``as in Java''}$
stringLit ::= $\mbox{\rm\em ``as in Java''}$
symbolLit ::= `\'' id
comment ::= `/*' ``any sequence of characters'' `*/'
| `//' `any sequence of characters up to end of line''
\end{lstlisting}
The context-free syntax of Scala is given by the following EBNF
grammar.
\begin{lstlisting}
Literal ::= intLit
| floatLit
| charLit
| stringLit
| symbolLit
| true
| false
| null
StableId ::= id
| Path `.' id
Path ::= StableId
| [id `.'] this
| [id '.'] super [`[' id `]']`.' id
Type ::= Type1 `=>' Type
| `(' [Types] `)' `=>' Type
| Type1
Type1 ::= SimpleType {with SimpleType} [Refinement]
SimpleType ::= SimpleType TypeArgs
| SimpleType `#' id
| StableId
| Path `.' type
| `(' Type ')'
TypeArgs ::= `[' Types `]'
Types ::= Type {`,' Type}
Refinement ::= `{' [RefineStat {`;' RefineStat}] `}'
RefineStat ::= Dcl
| type TypeDef {`,' TypeDef}
|
Exprs ::= Expr {`,' Expr}
Expr ::= Bindings `=>' Expr
| Expr1
Expr1 ::= if `(' Expr1 `)' Expr [[`;'] else Expr]
| try `{' Block `}' [catch Expr] [finally Expr]
| do Expr [`;'] while `(' Expr ')'
| for `(' Enumerators `)' (do | yield) Expr
| return [Expr]
| throw Expr
| [SimpleExpr `.'] id `=' Expr
| SimpleExpr ArgumentExprs `=' Expr
| PostfixExpr [`:' Type1]
PostfixExpr ::= InfixExpr [id]
InfixExpr ::= PrefixExpr
| InfixExpr id PrefixExpr
PrefixExpr ::= [`-' | `+' | `~' | `!'] SimpleExpr
SimpleExpr ::= Literal
| Path
| `(' [Expr] `)'
| BlockExpr
| new Template
| SimpleExpr `.' id
| SimpleExpr TypeArgs
| SimpleExpr ArgumentExprs
ArgumentExprs ::= `(' [Exprs] ')'
| BlockExpr
BlockExpr ::= `{' CaseClause {CaseClause} `}'
| `{' Block `}'
Block ::= {BlockStat `;'} [ResultExpr]
BlockStat ::= Import
| Def
| {LocalModifier} ClsDef
| Expr1
|
ResultExpr ::= Expr1
| Bindings `=>' Block
Enumerators ::= Generator {`;' Enumerator}
Enumerator ::= Generator
| Expr
Generator ::= val Pattern1 `<-' Expr
CaseClause ::= case Pattern [`if' PostfixExpr] `=>' Block
Constr ::= StableId [TypeArgs] [`(' [Exprs] `)']
Pattern ::= Pattern1 { `|' Pattern1 }
Pattern1 ::= varid `:' Type
| `_' `:' Type
| Pattern2
Pattern2 ::= [varid `@'] Pattern3
Pattern3 ::= SimplePattern [ '*' | '?' | '+' ]
| SimplePattern { id SimplePattern }
SimplePattern ::= `_'
| varid
| Literal
| StableId [ `(' [Patterns] `)' ]
| `(' [Patterns] `)'
Patterns ::= Pattern {`,' Pattern}
TypeParamClause ::= `[' TypeParam {`,' TypeParam} `]'
FunTypeParamClause ::= `[' TypeDcl {`,' TypeDcl} `]'
TypeParam ::= [`+' | `-'] TypeDcl
ParamClause ::= `(' [Param {`,' Param}] `)'
Param ::= [def] id `:' Type [`*']
Bindings ::= id [`:' Type1]
| `(' Binding {`,' Binding `)'
Binding ::= id [`:' Type]
Modifier ::= LocalModifier
| private
| protected
| override
LocalModifier ::= abstract
| final
| sealed
Template ::= Constr {`with' Constr} [TemplateBody]
TemplateBody ::= `{' [TemplateStat {`;' TemplateStat}] `}'
TemplateStat ::= Import
| {Modifier} Def
| {Modifier} Dcl
| Expr
|
Import ::= import ImportExpr {`,' ImportExpr}
ImportExpr ::= StableId `.' (id | `_' | ImportSelectors)
ImportSelectors ::= `{' {ImportSelector `,'}
(ImportSelector | `_') `}'
ImportSelector ::= id [`=>' id | `=>' `_']
Dcl ::= val ValDcl {`,' ValDcl}
| var VarDcl {`,' VarDcl}
| def FunDcl {`,' FunDcl}
| type TypeDcl {`,' TypeDcl}
ValDcl ::= id `:' Type
VarDcl ::= id `:' Type
FunDcl ::= id [FunTypeParamClause] {ParamClause} `:' Type
TypeDcl ::= id [`>:' Type] [`<:' Type]
Def ::= val PatDef {`,' PatDef}
| var VarDef {`,' VarDef}
| def FunDef {`,' FunDef}
| type TypeDef {`,' TypeDef}
| ClsDef
PatDef ::= Pattern `=' Expr
VarDef ::= id [`:' Type] `=' Expr
| id `:' Type `=' `_'
FunDef ::= id [FunTypeParamClause] {ParamClause}
[`:' Type] `=' Expr
| this ParamClause `=' ConstrExpr
TypeDef ::= id [TypeParamClause] `=' Type
ClsDef ::= ([case] class | trait) ClassDef {`,' ClassDef}
| [case] object ObjectDef {`,' ObjectDef}
ClassDef ::= id [TypeParamClause] [ParamClause]
[`:' SimpleType] ClassTemplate
ObjectDef ::= id [`:' SimpleType] ClassTemplate
ClassTemplate ::= extends Template
| TemplateBody
|
ConstrExpr ::= this ArgumentExprs
| `{' this ArgumentExprs {`;' BlockStat} `}'
CompilationUnit ::= [package QualId `;'] {TopStat `;'} TopStat
TopStat ::= {Modifier} ClsDef
| Import
| Packaging
|
Packaging ::= package QualId `{' {TopStat `;'} TopStat `}'
QualId ::= id {`.' id}
\end{lstlisting}
\chapter{Implementation Status}
\input{ImplementationStatus}
\end{document}
