1.语法文法G[E]如下所示:
E→E+T | E-T | T
T→T* F | T/F | F
F→P^ F | P
P→(E) | i
E→E1+T1 {E.place:=newtemp; emit(E.place , ":=" , E1.place‘+‘ , T1.place)}
E→E1-T1 {E.place:=newtemp; emit(E.place , ":=" , E1.place‘-‘ , T1.place)}
E→T1 {E.place:=T1.place;}
T→T1* F1 {T.place:=newtemp; emit(T.place , ":=" , T1.place‘*‘ , F1.place)}
T→T1/F1 {T.place:=newtemp; emit(T.place , ":=" , T1.place‘/‘ , F1.place)}
T→F1 {T.place:=F1.place;}
F→P1^ F1 {T.place:=newtemp; emit(F.place , ":=" , P1.place‘^‘ , F1.place)}
F→P1 {F.place:=newtemp; emit(F.place , ":=" , P1.place)}
P→(E1) {P.place:=E1.place}
P→i {p:=lookup(id.name); if p<>nil then P.place:=i else error}
原文:https://www.cnblogs.com/a131452/p/12058072.html