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所以我是新來的野牛，我想做一個簡單的計算器。 當我執行bison -d命令時，它說有7個減少/減少衝突，我不確定這是爲什麼，我知道這是因爲我的語法中存在一些錯誤的邏輯，我無法找到它。因此，這裏的代碼中不間斷文件：野牛問題與減少/減少衝突
%{
#include <stdio.h>
#include <stdlib.h>
#include <Math.h>
char** nizVarijabliI;
int* nizVrijednostiVarijabliI;
int* nizIinfo;
char** nizVarijabliD;
float** nizVrijednostiVarijabliD;
int* nizDinfo;
int countD = 100;
int dountI = 100;
void updateSymbolTableI(char* s,int br);
void updateSymbolTableD(char* s,float br
float symbolVal(char* s)
%}
%union{
double var1;
int var2;
char* varName;
}
%token <var1> DNUM
%token <var2> INUM
%token <varName> VARIABLE;
%token QUIT PLUS MINUS DIVIDE MULTIPLY EQUALS EXPONENTIATION SIN COS LOG POW SQRT LPAREN RPAREN NEWLINE
%right EQUALS
%left PLUS MINUS
%left DIVIDE MULTIPLY
%right EXPONENTIATION
%nonassoc UMINUS
%type <var1> mixExp
%type <var2> exp
%type <varName> assign
%start pocetak
%%
pocetak :
| pocetak line;
line : NEWLINE
| assign NEWLINE {;}
| mixExp NEWLINE {printf("%f\n",$1);}
| exp NEWLINE {printf("%d\n",$1);}
| QUIT NEWLINE {exit(1);}
;
mixExp : DNUM NEWLINE {$$ = $1;}
| SIN LPAREN mixExp RPAREN NEWLINE {$$ = sin($3);}
| COS LPAREN mixExp RPAREN NEWLINE {$$ = cos($3);}
| LOG LPAREN mixExp RPAREN NEWLINE {$$ = log($3);}
| SQRT LPAREN mixExp RPAREN NEWLINE {$$ = sqrt($3);}
| POW LPAREN mixExp "," mixExp RPAREN NEWLINE {$$ = pow($3,$5);}
| VARIABLE NEWLINE {$$ = symbolVal($1);}
| MINUS mixExp %prec UMINUS NEWLINE {$$ = -$2:}
| mixExp PLUS mixExp NEWLINE {$$ = $1 + $3;}
| mixExp MINUS mixExp NEWLINE {$$ = $1 - $3;}
| mixExp MULTIPLY mixExp NEWLINE {$$ = $1 * $3;}
| mixExp DIVIDE mixExp NEWLINE {$$ = $1/$3;}
| LPAREN mixExp RPAREN NEWLINE {$$ = $2;}
| mixExp PLUS exp NEWLINE {$$ = $1 + $3;}
| mixExp MINUS exp NEWLINE {$$ = $1 - $3;}
| mixExp MULTIPLY exp NEWLINE {$$ = $1 * $3;}
| mixExp DIVIDE exp NEWLINE {$$ = $1/$3;}
| exp PLUS mixExp NEWLINE {$$ = $1 + $3;}
| exp MINUS mixExp NEWLINE {$$ = $1 - $3;}
| exp MULTIPLY mixExp NEWLINE {$$ = $1 * $3;}
| exp DIVIDE mixExp NEWLINE {$$ = $1/$3;}
;
exp : INUM NEWLINE {$$=$1;}
| SIN LPAREN exp RPAREN NEWLINE {$$=sin($3);}
| COS LPAREN exp RPAREN NEWLINE {$$=cos($3);}
| LOG LPAREN exp RPAREN NEWLINE {$$=log($3);}
| SQRT LPAREN exp RPAREN NEWLINE {$$=sqrt($3);}
| POW LPAREN exp "," exp RPAREN NEWLINE {$$ = pow($3,$5);}
| VARIABLE NEWLINE {$$ = symbolVal($1);}
| MINUS exp %prec UMINUS NEWLINE {$$ = -$2:}
| exp PLUS exp NEWLINE {$$ = $1 + $3;}
| exp MINUS exp NEWLINE {$$ = $1 - $3;}
| exp MULTIPLY exp NEWLINE {$$ = $1 * $3;}
| exp DIVIDE exp NEWLINE {$$ = $1/$3;}
| LPAREN exp RPAREN NEWLINE {$$ = $2;}
;
assign : VARIABLE EQUALS exp NEWLINE {updateSymbolTableI($1,$3);}
| VARIABLE EQUALS mixExp NEWLINE {updateSymbolTableD($1,$3);}
;
%%
int main() {
int i;
nizVrijednostiVarijabliI = malloc(100*sizeof(int));
nizVrijednostiVarijabliD = malloc(100*sizeof(float));
nizIinfo = malloc(100*sizeof(int));
nizDinfo = malloc(100*sizeof(int));
for(i=0;i<100;i++) {nizIinfo[i] = 0; nizDinfo[i] = 0;}
nizVarijabliI = malloc(100*sizeof(char*));
for(i=0;i<100;i++) nizVarijabliI[i] = malloc(100*sizeof(char));
nizVarijabliD = malloc(100*sizeof(char*));
for(i=0;i<100;i++) nizVarijabliD[i] = malloc(100*sizeof(char));
yyparse();
return;
}
void updateSymbolTableI(char* s,int br)
{
int freeInd = -1;
int i;
for(i=0;i<countI;i++)
{
if(nizIinfo[i] == 0)
{
freeInd = i;
break;
}
}
if(freeInd == -1)
{
freeInd = i;
countI = countI * 2;
nizVrijednostiVarijabliI = realloc(nizVrijednostiVarijabliI,count*sizeof(int));
nizIinfo = realloc(nizIinfo,count*sizeof(int));
nizVarijabliI = realloc(nizVarijabliI,count*sizeof(char*));
}
nizVrijednostiVarijabliI[freeInd] = br;
nizIinfo[freeInd] = 1;
nizVarijabliI[freeInd] = s;
}
void updateSymbolTableD(char* s, float br)
{
int freeInd = -1;
int i;
for(i=0;i<countD;i++)
{
if(nizDinfo[i] == 0)
{
freeInd = i;
break;
}
}
if(freeInd == -1)
{
freeInd = i;
countD = countD * 2;
nizVrijednostiVarijabliD = realloc(nizVrijednostiVarijabliD,count*sizeof(float));
nizDinfo = realloc(nizDinfo,count*sizeof(int));
nizVarijabliD = realloc(nizVarijabliD,count*sizeof(char*));
}
nizVrijednostiVarijabliD[freeInd] = br;
nizDinfo[freeInd] = 1;
nizVarijabliD[freeInd] = s;
}
float symbolVal(char* s)
{
int ind = -1;
int i;
for(i=0;i<countI;i++)
{
if(strcmp(s,nizVarijabliI[i]) == 0)
{
ind = i;
return (float)nizVrijednostiVarijabliI[ind];
}
}
if(ind == -1)
{
for(i=0;i<countD;i++)
{
if(strcmp(s,nizVarijabliD[i]) == 0)
{
ind = i;
return nizVrijednostiVarijabliD[ind];
}
}
}
if(ind == -1) return 0;
}
另外這裏是我爲這個目的而作出的法文件：
%{
#include "ultcalc.tab.h";
%}
%%
"quit" {return QUIT;}
"sin" {return SIN;}
"cos" {return COS;}
"pow" {return EXPONENTIATION;}
"log" {return LOG;}
"sqrt" {return SQRT;}
[0-9]+"."[0-9]+ {yylval.var1 = atof(yytext); return DNUM;}
[a-z][a-zA-Z0-9]* {yylval.varName = yytext; return VARIABLE;}
[0-9]+ {yylval.var2 = atoi(yytext); return INUM;}
"=" {return EQUALS;}
"+" {return PLUS;}
"-" {return MINUS;}
"*" {return MULTIPLY;}
"/" {return DIVIDE;}
"(" {return LPAREN;}
")" {return RPAREN;}
"," {return yytext;}
[ \t] {;}
[\n] {return NEWLINE;}
. {yyerror("Neocekivani karakteri!");}
%%
yywrap() {return 1;}
任何意見將不勝感激。
這是很多代碼來通過，所以我沒有。但是，我注意到你正試圖在語法上檢測類型（整數或雙精度）。這不是一個好主意。解析後進行類型檢查。既然你有變量，並且不可能從它的名字中知道變量的類型，你最終會得到不明確的分析結果，這將被報告爲r/r衝突 – rici
另外，'yylval.varName = yytext;'是一個真正的不好的想法，''的動作應該是'return * yytext;'而不是'return yytext'。就個人而言，我會使用該動作來處理其他單字符標記類型（.operator和圓括號）。 – rici
是的，這與我所做的很相似，簡化了語法並以相同的方式接受了所有數字，而不僅僅是一些在C代碼中進行浮點投射。和''一樣，我現在用'return yytext [0]'代替它。 你也可以告訴我一個更好的方法來解決這個'yylval.varName = yytext;'，因爲它似乎當我用$ somenumber在野牛拿起VARIABLE時，它會拾取比它應該更多的字符，這可能是因爲你剛剛指出的是什麼？ @rici –