Hello,
I'm trying to use Bison to compile(i don't know if this is the correct word to use), but when i try to compile this source code:
%{
#define YYSTYPE double
#include <math.h>
#include <stdio.h>
%}
%token NUM
%%
input: /* empty */
| input line
;
line: '\n'
| exp '\n' { printf ("\t%.10g\n", $1); }
;
exp: NUM { $$ = $1; }
| exp exp '+' { $$ = $1 + $2; }
| exp exp '-' { $$ = $1 - $2; }
| exp exp '*' { $$ = $1 * $2; }
| exp exp '/' { $$ = $1 / $2; }
/* Exponentiation */
| exp exp '^' { $$ = pow ($1, $2); }
/* Unary minus */
| exp 'n' { $$ = -$1; }
;
%%
/* Lexical analyzer returns a double floating point
number on the stack and the token NUM, or the ASCII
character read if not a number. Skips all blanks
and tabs, returns 0 for EOF. */
#include <ctype.h>
#include <stdio.h>
yyerror(const char *s)
yylex ()
{
int c;
/* skip white space */
while ((c = getchar ()) == ' ' || c == '\t')
;
/* process numbers */
if (c == '.' || isdigit (c))
{
ungetc (c, stdin);
scanf ("%lf", &yylval);
return NUM;
}
/* return end-of-file */
if (c == EOF)
return 0;
/* return single chars */
return c;
}
yyerror (s) /* Called by yyparse on error */
char *s;
{
printf ("%s\n", s);
}
main ()
{
yyparse ();
}
I'm getting some "garbage" in the console(not in a file or something like), take a look: http://pastie.org/650893
Best Regards.