The composition of functions in a list of functions!

Question

I need to define a function \'Compose\' which takes a list \'L\' which is a list of functions. When I specify a parameter that will suit all the functions in the list, the l

Answer 1

If the solution is a one-line answer, it could be something involving a fold:

compose :: [a -> a] -> a -> a
compose fs v = foldl (flip (.)) id fs $ v

http://haskell.org/haskellwiki/Compose

You can also implement it as a right fold, which works the way you want:

compose = foldr (.) id

*Main> let compose = foldr (.) id
*Main> compose [\x -> x+1, \x -> 2 * x, id] 3
7