I have a function which behaves like map, except instead of applying the given function to, say, the element at position 5, it applies it to the entire list *without* the element at position 5. An implementation looks like:
> mapWithout :: ([a] -> b) -> [a] -> [b] > mapWithout f = mapWith' [] > where mapWith' pre [] = [] > mapWith' pre (x:xs) = f (pre ++ xs) : mapWith' (x:pre) xs Unfortunately, this is very slow, due to the overhead of (++). Any way I could speed this up would be great. Note that order doesn't matter to 'f', but I do need that the order in which the elements of the list are processed be the same as in map. - Hal -- Hal Daume III "Computer science is no more about computers | [EMAIL PROTECTED] than astronomy is about telescopes." -Dijkstra | www.isi.edu/~hdaume _______________________________________________ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
