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所以我是新来的野牛，我想做一个简单的计算器。 当我执行bison -d命令时，它说有7个减少/减少冲突，我不确定这是为什么，我知道这是因为我的语法中存在一些错误的逻辑，我无法找到它。因此，这里的代码中不间断文件：野牛问题与减少/减少冲突
%{
#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;
}
另外这里是我为这个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;}
任何意见将不胜感激。
这是很多代码来通过，所以我没有。但是，我注意到你正试图在语法上检测类型（整数或双精度）。这不是一个好主意。解析后进行类型检查。既然你有变量，并且不可能从它的名字中知道变量的类型，你最终会得到不明确的分析结果，这将被报告为r/r冲突 – rici
另外，'yylval.varName = yytext;'是一个真正的不好的想法，''的动作应该是'return * yytext;'而不是'return yytext'。就个人而言，我会使用该动作来处理其他单字符标记类型（.operator和圆括号）。 – rici
是的，这与我所做的很相似，简化了语法并以相同的方式接受了所有数字，而不仅仅是一些在C代码中进行浮点投射。和''一样，我现在用'return yytext [0]'代替它。 你也可以告诉我一个更好的方法来解决这个'yylval.varName = yytext;'，因为它似乎当我用$ somenumber在野牛拿起VARIABLE时，它会拾取比它应该更多的字符，这可能是因为你刚刚指出的是什么？ @rici –