1 files changed, 16 insertions, 7 deletions
diff --git a/Com/Simatime/Alpha.hs b/Com/Simatime/Alpha.hs
index 438b97a..16d21e3 100644
--- a/Com/Simatime/Alpha.hs
+++ b/Com/Simatime/Alpha.hs
@@ -1,24 +1,33 @@
 {-# LANGUAGE NoImplicitPrelude #-}
 -- | Commonly useful functions, a Prelude replacement.
-module Com.Simatime.Alpha (
+module Com.Simatime.Alpha
+  (
   -- * Re-export Protolude
-  module X
+    module X
   -- * General functions
   , (/@)
+  , (/@@)
   -- * Debugging tools
   , say
   -- * TODO: remove this
   , Prelude.read
-  ) where
+  )
+where
 
+import           Data.Text                      ( Text )
 import qualified Prelude
-import Protolude as X
-import Data.String
+import           Protolude                     as X
+import           Data.String
 
 -- | Debugging printf
-say :: String -> IO ()
+say :: Text -> IO ()
 say msg = putStrLn msg
 
--- | Alias for map, fmap, <$>
+-- | Alias for map, fmap, <$>. Inspired by Mathematica.
 (/@) :: Functor f => (a -> b) -> f a -> f b
 (/@) = fmap
+
+-- | Double fmap.
+-- (/@@) :: (Functor f1, Functor f2) => f1 (a -> b) -> f1 (f2 a) -> f1 (f2 b)
+(/@@) :: (Functor f0, Functor f1) => (a -> b) -> f0 (f1 a) -> f0 (f1 b)
+(/@@) = fmap . fmap