haskeline based framework

1 files changed, 30 insertions, 0 deletions

diff --git a/src/Utils.hs b/src/Utils.hs
new file mode 100644
index 0000000..2254fde
--- /dev/null
+++ b/src/Utils.hs
@@ -0,0 +1,30 @@
+{-# LANGUAGE ViewPatterns, OverloadedStrings, FlexibleContexts #-}
+
+module Utils
+       ( showEntity
+       , apply, apply'
+       ) where
+
+import Data.Text (Text)
+import qualified Data.Text as Text
+
+import Data.Monoid (Monoid(..), (<>))
+
+import Control.Monad.State.Class
+import Control.Monad.Writer.Class
+
+import Types
+
+showEntity :: Entity -> Text
+showEntity (Entity name number)
+  | (Just (show -> n)) <- number = name <> " № " <> Text.pack n
+  | otherwise = name
+
+apply' :: (MonadState Sequence m, MonadWriter History m) => Alteration -> m ()
+apply' alteration = do
+  (newSt, hist) <- apply alteration <$> get
+  tell hist
+  put newSt
+
+apply :: Alteration -> Sequence -> (Sequence, History)
+apply alteration seq = undefined