Deforestation1

import Data.Char
import Data.List

func = foldr (+) 0 . map (\x -> x * 10)

func' xs = foldr (+) 0 $ map (\x -> x * 10) xs

func'' xs = case map (\x -> x * 10) xs of
                                       [] -> 0
                                       x:xs -> x + foldr (+) 0 xs
func''' xs = case (case xs of
                           [] -> []
                           x:xs -> (\x -> x * 10) x : map (\x -> x * 10) xs) of
                                                                             [] -> 0
                                                                             x:xs -> x + foldr (+) 0 xs
func'''' xs = case xs of
                      [] -> case [] of
                                    [] -> 0
                                    x:xs -> x + foldr (+) 0 xs
                      x:xs -> case (\x -> x * 10) x : map (\x -> x * 10) xs of
                                                                            [] -> 0
                                                                            x:xs -> x + foldr (+) 0 xs

func''''' xs = case xs of
                       [] -> 0
                       x:xs -> (\x -> x * 10) x + foldr (+) 0 (map (\x -> x * 10) xs)

answer xs = case xs of
                    [] -> 0
                    x:xs -> (\x -> x * 10) x + answer xs