I think that in every particular case you have to find out how to avoid 'reverse'. Especially if you have two 'reverse's like in reverse . dropWhile p . reverse there are more efficient solutions.
Just from curiosity, what *is* an efficient way to do rDropWhile? Here's something which at least avoids 2 reverses: rDropWhile = doRDropWhile [] doRDropWhile accum f [] = [] doRDropWhile accum f (x:xs) | f x = doRDropWhile (x:accum) f xs | otherwise = reverse (x:accum) ++ doRDropWhile [] f xs I assume this is not in Data.List to discourage people from doing things to the right side of lists... it's still useful for string stuff where ByteString would be overkill though. _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
