TigerBook/PROGRAM3

Chapter 3 の PROGRAM

PROGRAM

いろいろ手探りでやった結果以下の通りになった。 シフト還元衝突が一つだけ残っている。%change などの option 作業は行っていない。

%%
%term
    EOF
  | ID of string
  | INT of int | STRING of string
  | COMMA | COLON | SEMICOLON | LPAREN | RPAREN | LBRACK | RBRACK
  | LBRACE | RBRACE | DOT
  | PLUS | MINUS | TIMES | DIVIDE | EQ | NEQ | LT | LE | GT | GE
  | AND | OR | ASSIGN
  | ARRAY | IF | THEN | ELSE | WHILE | FOR | TO | DO | LET | IN | END | OF
  | BREAK | NIL
  | FUNCTION | VAR | TYPE
  | UNARYMINUS
%nonterm  exp | program
	| lvalue
	| sequensing | expsemilist
	| functionCall | explistopt | explist 
	| opExpr
	| recordCreate | typeid | idExpList | recField
	| arrayCreate | assignment | ifThenElse | ifThen
	| whileClause | forClause
	| letexp | expseq
	| parentheses 
	| decs | dec
	| tydec | ty | tyfields | tyfieldlist | tyfield
	| vardec | fundec

%pos int
%verbose
%start program
%eop EOF
%noshift EOF

%name Tiger
%keyword WHILE FOR TO BREAK LET IN END FUNCTION VAR TYPE ARRAY IF THEN ELSE
	DO OF NIL

%prefer THEN ELSE LPAREN

%value ID ("bogus")
%value INT (1)
%value STRING ("")

%nonassoc ASSIGN
%left DO THEN ELSE OF
%left OR
%left AND
%nonassoc EQ NEQ LT LE GT GE
%left PLUS MINUS
%left TIMES DIVIDE
%left UNARYMINUS

%%
program	: exp        ()

(***** Expressions *****)
exp: lvalue          ()
   | NIL             ()
   | sequensing      ()
   | INT             ()
   | STRING          ()
   | functionCall    ()
   | opExpr          ()
   | recordCreate    ()
   | arrayCreate     ()
   | assignment      ()
   | ifThenElse      ()
   | ifThen          ()
   | whileClause     ()
   | forClause       ()
   | BREAK           ()
   | letexp          ()
   | parentheses     ()

lvalue : ID          ()
       | lvalue COLON ID ()
       | lvalue LBRACK exp RBRACK ()

sequensing     : LPAREN expsemilist RPAREN ()
expsemilist : expsemilist SEMICOLON exp ()
    	    | exp SEMICOLON exp ()           (* Excl. Parentheses *)

functionCall   : ID LPAREN explistopt RPAREN ()
explistopt : explist ()
	   |         ()  (* empty *)
explist    : explist COMMA exp ()
           | exp               ()

opExpr  : exp DIVIDE exp ()
	| exp TIMES exp ()
	| exp MINUS exp ()
	| exp PLUS  exp ()
	| exp EQ  exp ()
	| exp NEQ exp ()
	| exp GE  exp ()
	| exp GT  exp ()
	| exp LE  exp ()
	| exp LT  exp ()
	| exp AND exp ()
	| exp OR  exp ()
        | MINUS exp %prec UNARYMINUS ()

recordCreate   : ID LBRACE idExpList RBRACE () (* typeid *)
typeid : ID ()
idExpList : recField ()
	  | idExpList COMMA ID recField ()
recField : ID EQ exp ()

arrayCreate    : ID LBRACK exp RBRACK OF exp () (* typeid *)
assignment     : lvalue ASSIGN exp ()
ifThen         : IF exp THEN exp          ()
ifThenElse     : IF exp THEN exp ELSE exp ()
whileClause    : WHILE exp DO exp         ()
forClause      : FOR ID ASSIGN exp TO exp DO exp ()
letexp         : LET decs IN expseq END   ()
expseq : expsemilist ()
       | exp ()
       | ()
parentheses    : LPAREN exp RPAREN        ()

(***** Declaration *****)
decs :               () (* empty *)
     |  decs dec     ()

dec : tydec  ()
    | vardec ()
    | fundec ()

tydec : TYPE typeid EQ ty ()
ty : typeid ()
   | LBRACE tyfields RBRACE ()
   | ARRAY OF typeid ()
tyfields : ()  (* empty *)
	 | tyfieldlist ()
tyfieldlist : tyfieldlist COMMA tyfield ()
	    | tyfield ()
tyfield : ID COLON typeid ()

vardec : VAR ID ASSIGN exp ()
       | VAR ID COLON typeid ASSIGN exp ()

fundec : FUNCTION ID LPAREN tyfields RPAREN EQ exp ()
       | FUNCTION ID LPAREN tyfields RPAREN COLON typeid EQ exp ()