Re: [Haskell-cafe] Established names for a couple of list functionals?

On Tue, 6 Apr 2010 21:56:37 +0100, Stephen Tetley wrote:

Hello all

Having traversals with special behaviour for the first or last element is useful for my current work:

-- first element special -- anacrusisMap :: (a -> b) -> (a -> b) -> [a] -> [b] anacrusisMap _ _ [] = [] anacrusisMap f g (a:as) = f a : map g as

I think it makes for sense to not wire in the map function. firstOthers :: (a -> b) -> ([a] -> [b]) -> [a] -> [b] firstOthers _ _ [] = [] firstOthers f g (x:xs) = f x : g xs Then anacrusisMap is so short that we don't give it a name. anacrusisMap f = firstOthers f . map Same thing goes to the other one. Regards, -- Nicolas Pouillard http://nicolaspouillard.fr