returns the largest value. Returns 0 if @var{haystack} does not contain
any part in @var{needle}. It is an error if @var{needle_len} does not
evenly divide the length of @var{needle}. Returns system-missing
returns the largest value. Returns 0 if @var{haystack} does not contain
any part in @var{needle}. It is an error if @var{needle_len} does not
evenly divide the length of @var{needle}. Returns system-missing