Function adddigit

3rd/lua-5.4.3/src/lstrlib.c:1016–1021

** Add integer part of 'x' to buffer and return new 'x' */

** Add integer part of 'x' to buffer and return new 'x'
*/
static lua_Number adddigit (char *buff, int n, lua_Number x) {
  lua_Number dd = l_mathop(floor)(x);  /* get integer part from 'x' */
  int d = (int)dd;
  buff[n] = (d < 10 ? d + '0' : d - 10 + 'a');  /* add to buffer */
  return x - dd;  /* return what is left */
}


static int num2straux (char *buff, int sz, lua_Number x) {