/*
 * call-seq: scan_until(pattern)
 *
 * Scans the string _until_ the +pattern+ is matched.  Returns the substring up
 * to and including the end of the match, advancing the scan pointer to that
 * location. If there is no match, +nil+ is returned.
 *
 *   s = StringScanner.new("Fri Dec 12 1975 14:39")
 *   s.scan_until(/1/)        # -> "Fri Dec 1"
 *   s.pre_match              # -> "Fri Dec "
 *   s.scan_until(/XYZ/)      # -> nil
 */
static VALUE
strscan_scan_until(self, re)
    VALUE self, re;
{
    return strscan_do_scan(self, re, 1, 1, 0);
}