/*
 *  call-seq:
 *     LetterTokenizer.new(lower = true) -> tokenizer
 *
 *  Create a new LetterTokenizer which optionally downcases tokens. Downcasing
 *  is done according the the current locale.
 *
 *  lower:: set to false if you don't wish to downcase tokens
 */
static VALUE
frt_letter_tokenizer_init(int argc, VALUE *argv, VALUE self) 
{
    TS_ARGS(false);
    if (!frt_locale) frt_locale = setlocale(LC_CTYPE, "");
    return get_wrapped_ts(self, rstr, mb_letter_tokenizer_new(lower));
}