Rot13 in Haskell

Welcome to the Rot13 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 Data.Char
import System.Environment
import System.Exit (exitWith, ExitCode(ExitFailure))

rot13 :: String -> String
rot13 = map encryptChar

encryptChar :: Char -> Char
encryptChar c
  | ord c >= 65 && ord c <= 90  = toChar 65 $ addDigits $ toNum 65 c
  | ord c >= 97 && ord c <= 122 = toChar 97 $ addDigits $ toNum 97 c
  | otherwise = c
    where toNum base c = (ord c) - base
          toChar base n = chr $ n + base
          addDigits n = (n + 13) `mod` 26



main :: IO ()
main = do
  args <- getArgs
  if null args || (head args) == "" then do
    putStrLn "Usage: please provide a string to encrypt"
    exitWith $ ExitFailure 1
  else
    putStrLn $ rot13 $ head args

Rot13 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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