Automata-2019

μJ1 Specification

program → method

method → ident ( identList_opt ) { declaration_opt statement_rep }

identList → ident

identList , ident

declaration → var identList ;

statement → assignment

printStat

assignment → variable = expression ;

expression → –opt term

expression + term

expression – term

term → factor

term * factor

term / factor

factor → number

variable

( expression )

variable → ident

printStat → print itemList ;

println itemListopt ;

itemList → printItem

itemList , printItem

printItem → literal

expression

expression : expression

μJ2 Specification

statement → assignment

printStat

readStat

whileStat

ifStat

readStat → read literal_opt ,_opt variable ;

whileStat → while condition block

ifStat → if condition block elsePart_opt

elsePart → else block

else ifStat

condition → ( expression relation expression )

block → { }

{ statementrep }

μJ3 Specification

program → method_rep

statement → assignment

printStat

readStat

whileStat

ifStat

returnStat

assignment → variable = expression ;

invocation ;

factor → number

variable

( expression )

invocation

invocation → ident ( exprList_opt )

exprList → expression

exprList , expression

returnStat → return expression_opt ;

Lexical Forms

token        ident | number | literal | keyword | relation | operator | separator

keyword      var | print | println | read | while | if | else | return 

relation     ==  !=  <   <=  >   >=

operator     =   +   -   *   /

separator    (   )   {   }   ,   ;   :

In-line comments // are skipped in the lexical stage
opt means optional,  rep means repeated one or more time