On Sun, 2006-07-02 at 23:08 +0400, Bulat Ziganshin wrote:
Hello Brian,
Sunday, July 2, 2006, 10:58:29 PM, you wrote:
fromString :: String -> Atom toString :: Atom -> String
instance Eq Atom instance Ord Atom -- this is where things get difficult!
i think that ByteString is a very strong candidate to Atom. `memicmp` is very fast operation, unless you plan to use really large strings with the same beginnings
and also equal lengths. The nice thing about the ByteString representation is that we can use the length to short-cut inequality and use equality of the pointers to short-cut equality: eq :: ByteString -> ByteString -> Bool eq a@(PS p s l) b@(PS p' s' l') | l /= l' = False -- short cut on length | p == p' && s == s' = True -- short cut for the same string | otherwise = compareBytes a b == EQ So the worst case is long strings that compare equal but have different memory blocks. Duncan