vigenere

vigenere.hs

import Data.Char
import Debug.Trace

vigenere input keyword = let in_ord  = trace "1" (map ((subtract 65) . ord) input) 
                             key_ord = (map  ((subtract 65) . ord) $  take  (length input) (cycle keyword))
                             sum_ord = zipWith (+) in_ord key_ord 
                             next = map (mod 25) sum_ord
                             last = map (+ 65) sum_ord
                             in map chr last