Haskell Quiz/Phone Number Words/Solution Jethr0
< Haskell Quiz | Phone Number Words
Categories: Haskell Quiz solutions
dictionary = map (map toUpper) ["haskell", "join", "the", "quiz"] -- fetch all possible words represented by a string of consecutive digits -- the results are checked against the dictionary -- if no result is found, the original string is returned as possibility allPoss xs = if null result then [xs] else result where result = filter (`elem` dictionary) . sequence . map poss $ xs poss char = encodings!!(read [char] :: Int) encodings = ["0", "1", "ABC", "DEF", "GHI", "JKL", "MNO", "PQRS", "TUV", "WXYZ"] splitThem [] = [] splitThem xs = y : rest where (y,ys) = break (not . isDigit) xs rest = splitThem . dropWhile (not . isDigit) $ ys -- > phoneNames "1.800.5646.843.4275355.7849" -- ["1-800-JOIN-THE-HASKELL-QUIZ"] phoneNames = map (concat . intersperse "-") . sequence . map allPoss . splitThem