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|
%{
#include <stdio.h>
#include <math.h>
%}
%union {
double value;
char* name;
}
%token <value> NUMBER
%type <value> expr
%left '+' '-'
%right SQRT
%left '*' '/'
%right '^'
%right UMINUS
%%
lines: lines expr '\n' { printf("%.10g\n", $2); }
| lines '\n'
| error '\n' { printf("Please re-enter last line: ");
yyerrok; }
|
;
expr: expr '+' expr { $$ = $1 + $3; }
| expr '-' expr { $$ = $1 - $3; }
| expr '*' expr { $$ = $1 * $3; }
| expr '/' expr { $$ = $1 / $3; }
| expr '^' expr { $$ = pow($1, $3); }
| '(' expr ')' { $$ = $2; }
| '-' expr %prec UMINUS { $$ = -$2; }
| NUMBER
;
%%
#include <ctype.h>
#include <stdio.h>
int main (int argc, char **argv)
{
return yyparse ();
}
int yyerror (char* errstr)
{
printf ("Error: %s\n", errstr);
return 1;
}
|
