#include "num.h"

num num_tostring_nonneg(char *s,num x)
{
  num len = 1;
  num q = x;
  if (x < 0) return 0;
  while (q > 9) { ++len; q /= 10; }
  if (s) {
    s += len;
    do { *--s = '0' + (x % 10); x /= 10; } while(x);
  }
  return len;
}