zipper test

gistfile1.fs

module test =
   open Zipper

   let t  = Branch("a", Branch("b", Leaf, Branch("c", Leaf, Leaf)), Leaf) 
   let focus1 = t |> fromTree |> move [Left;Right]
   let same1  = t |> fromTree |> move [Left;Right;Right;Up;Up;Up]
   let same2  = t |> fromTree |> move [Left;Right;Right] |>  Zipper.top
   let xx   =  focus1 |> top
   let newz =  {(move [Left;Right;Right] xx) with focus = t} |> top