int Formula::eval_neq(char *&s, Args *args, bool *vars) const
{
int left = eval_sum(s, args, vars);
while (*s)
{
if (myisspace(*s))
{
++s;
} else
if (*s == '<')
{
// this is needed due to side effects caused by min() macro...
int tmp = eval_sum(++s, args, vars);
left = min(left, tmp);
} else
if (*s == '>')
{
// this is needed due to side effects caused by max() macro...
int tmp = eval_sum(++s, args, vars);
left = max(left, tmp);
} else
{
break;
}
}
return left;
}
static int eval_exp(const char **s)
{
int base;
while (isspace(**s))
++*s;
switch (**s) {
// Unary '+' and '-' operators
case '+': ++*s; base = eval_exp(s); break;
case '-': ++*s; base = -eval_exp(s); break;
case '(':
++*s; // Eat "("
base = eval_sum(s);
if (**s != ')')
longjmp(err_jmp_buf, 1);
++*s; // Eat ")"
break;
default:
base = eval_num(s);
}
// Check if we have an exponent
while (isspace(**s))
++*s;
if (**s == '*' && *(*s + 1) == '*') {
*s += 2; // Eat "**"
return pow(base, eval_exp(s));
}
return base;
}
bool eval(const char *s, int *res)
{
int tmp;
if (setjmp(err_jmp_buf) == 1)
return false;
tmp = eval_sum(&s);
if (*s != '\0')
// Found extra trailing characters
return false;
*res = tmp;
return true;
}
