add logFirstAndRetSecond (#25)

Author: d1skort

MonadsAndEffects/3.3/logFirstAndRetSecond.hs

@@ -0,0 +1,15 @@
+module LogFirstAndRetSecond where
+
+
+import Control.Monad.Trans.Writer
+import Control.Monad.Trans.Reader
+import Control.Monad.Trans (lift)
+import Data.Char (toUpper)
+
+
+logFirstAndRetSecond :: WriterT String (Reader [String]) String
+logFirstAndRetSecond = do
+  e2 <- lift $ asks (map toUpper . head . tail)
+  e1 <- lift $ asks head
+  tell e1
+  return e2