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Versions: 268
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Contents
module AtbashCipher
( decode
, encode
) where
import Prelude
import Data.Array (drop, filter, take, zip, (:))
import Data.Char.Unicode (isPunctuation, isSpace)
import Data.Map (Map, fromFoldable, lookup)
import Data.Maybe (Maybe)
import Data.String (fromCharArray, joinWith, toCharArray, toLower)
import Data.Traversable (traverse)
plain :: Array Char
plain = toCharArray "abcdefghijklmnopqrstuvwxyz0123456789"
cipher :: Array Char
cipher = toCharArray "zyxwvutsrqponmlkjihgfedcba0123456789"
decMap :: Map Char Char
decMap = fromFoldable (zip cipher plain)
encMap :: Map Char Char
encMap = fromFoldable (zip plain cipher)
decode :: String -> Maybe String
decode s = fromCharArray <$> dec (toCharArray s)
where dec = filter ((/=) ' ')
>>> traverse (_ `lookup` decMap)
chunks :: forall a. Int -> Array a -> Array (Array a)
chunks n [] = []
chunks n a = take n a : chunks n (drop n a)
encode :: String -> Maybe String
encode s = group <$> enc (toLower s # toCharArray)
where enc = filter (not (isPunctuation || isSpace))
>>> traverse (_ `lookup` encMap)
group = chunks 5
>>> map fromCharArray
>>> joinWith " "
Version data entries
268 entries across 268 versions & 1 rubygems