Use Data.Text

src/Alea/Diceware.hs

@@ -1,28 +1,42 @@
+{-# LANGUAGE OverloadedStrings #-}
+
 module Alea.Diceware where
 
+import Data.Monoid   ((<>))
 import Data.List     (intersect, elemIndex)
-import Alea.List
+import Data.Text     (Text, pack)
+import System.Random
+import qualified Data.Text as T
 
--- Diceware dictionary type
-type Diceware = [String]
 
--- Parse file content to a Diceware
-parseDiceware :: String -> Diceware
-parseDiceware x = map (last . split ' ') $ lines x
+-- | Diceware dictionary alias
+type Diceware = [Text]
 
--- Lookup word with dice index
-readDiceware :: Diceware -> Int -> String
-readDiceware d n = show n ++ " -> " ++
-  case (undice n) of
-    Just x -> d !! x
-    Nothing -> "Does not exist"
 
--- Lookup word with linear index
-readDiceware' :: Diceware -> Int -> String
+-- | Produces k random indices to be extracted
+randIndices :: Int -> Int -> IO [Int]
+randIndices n k = take k <$> randomRs (0, n-1) <$> newStdGen
+
+
+-- | Parse file content to a Diceware
+parseDiceware :: Text -> Diceware
+parseDiceware = map (last . T.splitOn " ") . T.lines
+
+
+-- | Lookup word with dice index
+readDiceware :: Diceware -> Int -> Text
+readDiceware d n =
+  pack (show n) <> " -> " <>
+  maybe "Does not exists" (d !!) (fromDice n)
+
+
+-- | Lookup word with linear index
+readDiceware' :: Diceware -> Int -> Text
 readDiceware' d n = d !! n
 
--- Dice numbers to numbers
--- Ex. undice 11121 == Just 6
-undice :: Int -> Maybe Int
-undice n = elemIndex n . filter
-  (null . (intersect "0789") . show) $ [11111..66666]
+
+-- | Dice numbers to numbers
+-- > fromDice 11121 == Just 6
+fromDice :: Int -> Maybe Int
+fromDice n = elemIndex n (filter isDice [11111..66666])
+  where isDice = null . (intersect "0789") . show

src/Alea/List.hs

@@ -1,10 +0,0 @@
-module Alea.List where
-
--- Split a list into a list of lists
--- ex. split ',' "ab,cd,ef" == ["ab","cd","ef"]
-split :: (Eq a) => a -> [a] -> [[a]]
-split _ [] = [[]]
-split delim (c:cs)
-  | c == delim = [] : rest
-  | otherwise = (c : head rest) : tail rest
-  where rest = split delim cs

src/Main.hs

@@ -61,7 +61,7 @@ diceware args@ProgArgs{..} = do
   if interactive
     then forever (fmap dice I.getLine >>= I.putStrLn)
     else do
-      indices <- genIndex size phraseLength
+      indices <- randIndices size phraseLength
       I.putStrLn $ T.unwords (map dice' indices)
       when (phrases > 1) $
         diceware args {phrases = phrases - 1}