Two functions that I see useful are described here and I would like to know if they are defined in some more or less standard Haskell library. Hoogle (http://www.haskell.org/hoogle) did not reveal anything about that. Function 'inter' applies given function to each succeeding pair of elements of a list. inter :: (a -> a -> b) -> [a] -> [b] inter f [] = [] inter f l = map (uncurry f) $ zip l (tail l) Example usage: and $ inter (<=) l -- checks if 'l' is ordered inter (,) l -- gives succeeding pairs Function 'withPair' takes a pair and applies a function to it's first element, another function to it's second element and finally combines the results with yet another function. withPair :: (a' -> b' -> c) -> (a -> a') -> (b -> b') -> (a,b) -> c withPair f fa fb (a,b) = fa a `f` fb b Example usage: words [] = [] words s = withPair (:) id words (break isSpace $ dropWhile isSpace s) lines [] = [] lines s = withPair (:) id lines (break (== '\n') s) mapPair = withPair (,) This function can abstract away the (in my opinion ugly) pattern (as seen in the examples): foo list = let (a,b) = <somefun> list in <somefun2> a `<combinedWith>` foo b Anyone knows about these two functions or variants thereof? Cheers /Johan