Use the Show instance from Data.NumInstances for functions

rather than defining one locally.

The local definition conflicts in some cases, and prevents compiling.

Graphics/Implicit/Definitions.hs

@@ -10,7 +10,8 @@ module Graphics.Implicit.Definitions where
 import Data.IORef (IORef, newIORef, readIORef)
 import System.IO.Unsafe (unsafePerformIO)
 import Data.VectorSpace       
-import Control.Applicative       
+import Control.Applicative
+import Data.NumInstances
 
 -- Let's make things a bit nicer. 
 -- Following math notation ℝ, ℝ², ℝ³...
@@ -158,11 +159,6 @@ type Rectilinear2 = [Box2]
 -- | Rectilinear 2D set
 type Rectilinear3 = [Box3]
 
--- | Make ALL the functions Showable!
---   This is very handy when testing functions in interactive mode...
-instance Show (a -> b) where
-	show f = "<function>"
-
 -- | Now for something that makes me a bad person...
 --   I promise I'll use it for good, not evil!
 --   I don't want to reparse the program arguments 

implicit.cabal

@@ -34,7 +34,8 @@ Library
         blaze-markup,
         blaze-svg,
         storable-endian,
-        JuicyPixels
+        JuicyPixels,
+        NumInstances
 
     ghc-options:
         -O2 -optc-O3