Even Odd in Haskell

Welcome to the Even Odd in Haskell page! Here, you'll find the source code for this program as well as a description of how the program works.

Current Solution

module Main where

import System.Environment
import Text.Read

data EvenOdd = Even | Odd deriving (Show)

isEvenOdd :: Int -> EvenOdd
isEvenOdd x
  | x `mod` 2 == 0 = Even
  | otherwise  = Odd

headMaybe :: [a] -> Maybe a
headMaybe []     = Nothing
headMaybe (x:xs) = Just x

main :: IO ()
main = do
  args <- getArgs
  let x = headMaybe args
  case x >>= readMaybe of
    Nothing -> putStrLn "Usage: please input a number"
    Just x  -> putStrLn $ show $ isEvenOdd x

Even Odd in Haskell was written by:

• Parker Johansen

If you see anything you'd like to change or update, please consider contributing.

How to Implement the Solution

No 'How to Implement the Solution' section available. Please consider contributing.

How to Run the Solution

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