I've added a new type UNil to Core.Geometry and added affine instances for Pair and Maybe.
I believe I can unify the graphic types in Wumpus.Basic.Kernel.Objects by making them all extensions of Image
> type Image u a = CF (a, Prim u)
> i.e. type Image u a = DrawingContext -> (a, Prim u)
Currently I have Graphic to be different from Image:
> type Graphic u = DrawingContext -> Prim u
But I think if I make it this type:
> type Graphic u = Image u (UNil u)
> i.e. type Graphic u = DrawingContext -> (UNil u, Prim u)
Then the dichotomy between Image and Graphic vanishes so they can use the same functions.
