Fourteenth job - semantic syntax-directed translation of

1. The syntax grammar G [E] is as follows: 

–E→E+T | E-T | T 

–T→T* F | T/F | F 

–F→P^ F | P 

–P→(E) | i 

• Requirements constructed attribute grammar analysis requirements described semantically 

E→E+T {E.place:=newtemp;　　emit(E.place,':=',E.place'+',T.place)}

E→E-T {E.place:=newtemp;　　emit(E.place,':=',E.place'-',T.place)}

E → T {E.place:=newtemp; emitting (E.place, '=', T.place)}

 

T→T* F {T.place:=newtemp;　　emit(T.place,':=',T.place'*',F.place)}

T→T/F {T.place:=newtemp;　　emit(T.place,':=',T.place'/',F.place)}

T→F {T.place:=newtemp;　　emit(T.place, ':=', F.place)}

 

F→P^ F  {F.place:=newtemp;　　emit(F.place,':=',P.place'^',F.place)}

F→P {F.place:=newtemp;　　emit(F.place, ':=', P.place)}

 

P→(E)  {P.place:=E.place;　　}

P→i {if i<>nil then　emit(P.place, ':=', i.place)　　else error}

 

2. (OPTIONAL) third experiment: Syntax-Semantics translator

Claim:

• To achieve the above expression grammar analysis by operator priority syntax-directed translation process.
• Upon completion of the second experiment (operator priority syntax analysis) on the semantic analysis program design.
• The final output is equivalent to the test Quaternion intermediate code sequence.

Such as

Input: a + b * c, the output

(*,b,c,T1)

(+,a,T1,T2)

Input: b * (c + b) * d, the output

(*,b,c,T1)

(*,b,d,T2)

(+, T1, T2, T3)