Fossil

** Return TRUE if z is a pure numeric string.  Return FALSE if the
** string contains any character which is not part of a number. If
** the string is numeric and contains the '.' character, set *realnum
** to TRUE (otherwise FALSE).
**
** An empty string is considered non-numeric.
*/
static int sqlite3IsNumber(const char *z, int *realnum){
  int incr = 1;
  if( *z=='-' || *z=='+' ) z += incr;
  if( !th_isdigit(*(u8*)z) ){
    return 0;
  }
  z += incr;
  if( realnum ) *realnum = 0;

** is not, the result is undefined.
**
** This routine is used instead of the library atof() function because
** the library atof() might want to use "," as the decimal point instead
** of "." depending on how locale is set.  But that would cause problems
** for SQL.  So this routine always uses "." regardless of locale.
*/
static int sqlite3AtoF(const char *z, double *pResult){
  int sign = 1;
  const char *zBegin = z;
  LONGDOUBLE_TYPE v1 = 0.0;
  while( th_isspace(*(u8*)z) ) z++;
  if( *z=='-' ){
    sign = -1;
    z++;

*/
int Th_ToDouble(
  Th_Interp *interp, 
  const char *z, 
  int n, 
  double *pfOut
){
  if( !sqlite3IsNumber((const char *)z, 0) ){
    Th_ErrorMessage(interp, "expected number, got: \"", z, n);
    return TH_ERROR;
  }

  sqlite3AtoF((const char *)z, pfOut);
  return TH_OK;
}

/*
** Set the result of the interpreter to the th1 representation of
** the integer iVal and return TH_OK.
*/