functor module

protolude.cabal

@@ -35,6 +35,7 @@ library
     Monad
     Show
     Unsafe
+    Functor
 
   default-extensions:
     NoImplicitPrelude

src/Debug.hs

@@ -1,15 +1,15 @@
 {-# LANGUAGE NoImplicitPrelude #-}
 
 module Debug (
-    undefined
+  undefined,
-  , error
+  error,
-  , trace
+  trace,
-  , traceM
+  traceM,
-  , traceIO
+  traceIO,
-  , traceShow
+  traceShow,
-  , traceShowM
+  traceShowM,
-  , notImplemented
+  notImplemented,
-  ) where
+) where
 
 import qualified Prelude as P
 import qualified Debug.Trace as T

src/Functor.hs

@@ -0,0 +1,29 @@
+{-# LANGUAGE CPP #-}
+{-# LANGUAGE NoImplicitPrelude #-}
+
+module Functor (
+  Functor(..),
+  ($>),
+  (<$>),
+  void,
+) where
+
+#if (__GLASGOW_HASKELL__ >= 710)
+import Data.Functor (
+    Functor(..)
+  , ($>)
+  , (<$>)
+  , void
+  )
+#else
+import Data.Functor (
+    Functor(..)
+  , (<$>)
+  )
+
+($>) :: Functor f => f a -> b -> f b
+($>) = flip (<$)
+
+void :: Functor f => f a -> f ()
+void x = () <$ x
+#endif