Re: isSpace is too slow

Duncan Coutts wrote:

iswspace... We could short-cut that for ascii characters.

Also, '\t', '\n', '\r', '\f', and '\v' are contiguous. So isSpace c = c == ' ' || c <= '\r' && c >= '\t' || c == '\xa0' || c > '\xff' && iswspace (fromIntegral (ord c)) /= 0 That makes 4 comparisons or less in the common cases. If we assume that ascii characters greater than '\xa0' occur much less often than average, we can short-cut those also and cut it down to 3 or less. Note that the first space character above 255 is '\x1680' (according to isSpace). -Yitzchak