ExceptT2.hs

module ExceptT2 where

import Control.Monad.Trans.Maybe
import Data.Char (isNumber, isPunctuation)

import Control.Monad (guard)
import Control.Monad.Trans.Except
import Control.Monad.IO.Class (liftIO)
import Data.Foldable (msum)
import Data.Char (isNumber, isPunctuation)

askPassword0 :: MaybeT IO ()
askPassword0 = do
  liftIO $ putStrLn "Enter your new password:"
  value <- msum $ repeat getValidPassword0
  liftIO $ putStrLn "Storing in database..."

getValidPassword0 :: MaybeT IO String
getValidPassword0 = do
  s <- liftIO getLine
  guard (isValid0 s)
  return s

isValid0 :: String -> Bool
isValid0 s = length s >= 8
            && any isNumber s
            && any isPunctuation s