Lisa’s Haskell snippet

fruits.hs

#!/usr/bin/env stack
-- stack --resolver lts-17.9 script

module Main where

import Data.List

numbers        = [2..9]
fruits         = ["apple", "banana", "eggplant", "cherry", "kiwi", "tomato"]
vegetables     = ["carrot", "tomato", "celery", "eggplant", "spinach"]
squares        = map (^2) numbers
stupidfruits   = intersect fruits vegetables
realvegetables = vegetables \\ fruits

main = do
  putStrLn $ "       squares: " <> show numbers
  putStrLn $ "  stupidfruits: " <> show stupidfruits
  putStrLn $ "realvegetables: " <> show realvegetables

$ ./fruits.hs 
       squares: [2,3,4,5,6,7,8,9]
  stupidfruits: ["eggplant","tomato"]
realvegetables: ["carrot","celery","spinach"]