some fixes

Author: MAnyKey

ITMOPrelude/Categories.hs

@@ -5,10 +5,13 @@ import ITMOPrelude.Primitive
 import ITMOPrelude.List
 import ITMOPrelude.Tree
 
--- class Category cat where
---   id :: cat a a
---   (.) :: cat b c -> cat a b -> cat a c
-
+class Category cat where
+  id :: cat a a
+  (.) :: cat b c -> cat a b -> cat a c
+  
+instance Category (->) where
+  id = \x -> x
+  f . g = \x -> f (g x)
 
 class Functor f where
   fmap :: (a -> b) -> f a -> f b
@@ -63,6 +66,4 @@ newtype State s a = State { runState :: s -> (s, a) }
 instance Monad (State s) where
     return a = State $ \s -> (s, a)
     ma >>= f = State $ \s -> let (s', a) = runState ma s 
-                             in runState (f a) s'
-
-                              
+                             in runState (f a) s'

ITMOPrelude/IO.hs

@@ -1,7 +1,7 @@
 {-# LANGUAGE NoImplicitPrelude #-}
 module ITMOPrelude.IO where
 
-import ITMOPrelude.Primitive
+import ITMOPrelude.Primitive hiding ((.))
 import ITMOPrelude.List
 import ITMOPrelude.Categories
 
@@ -14,12 +14,10 @@ type IO a = State RealWorld a
 
 getNat :: IO Nat
 getNat = State getNat' 
-  where getNat' world = (newWorld, value) 
+  where getNat' world = (newWorld, value)
           where newWorld = RealWorld (tail . stdIn $ world) (stdOut world) (exitCode world)
                 value = head . stdIn $ world
 
-
-
 putNat :: Nat -> IO ()
 putNat n = State putNat'
   where putNat' world = (newWorld, ())