cleanup & stumped on variadic val

1 files changed, 27 insertions, 0 deletions

diff --git a/src/Sequence/Utils/Ask.hs b/src/Sequence/Utils/Ask.hs
new file mode 100644
index 0000000..8020656
--- /dev/null
+++ b/src/Sequence/Utils/Ask.hs
@@ -0,0 +1,27 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Sequence.Utils.Ask
+  ( askQ, askBool
+  ) where
+
+import System.Console.Readline (readline)
+
+import Control.Monad.IO.Class
+import Control.Monad
+
+import Data.CaseInsensitive (CI)
+import qualified Data.CaseInsensitive as CI
+
+import Data.Maybe
+
+askBool :: MonadIO m => String -> Bool -> m Bool
+askBool prompt initial = askQ prompt $ fromMaybe initial . join . fmap (eval . CI.mk)
+  where
+    eval "yes" = Just True
+    eval "y" = Just True
+    eval "no" = Just False
+    eval "n" = Just False
+    eval _ = Nothing
+
+askQ :: MonadIO m => String -> (Maybe String -> a) -> m a
+askQ prompt eval = eval <$> liftIO (readline $ prompt ++ " ")