[Haskell-cafe] newbie problems

paolo veronelli paolo_veronelli at yahoo.it
Sat Jul 3 16:29:54 EDT 2004


On Sat, 3 Jul 2004 17:57:04 +0100 (BST), MR K P SCHUPKE 
<k.schupke at imperial.ac.uk> wrote:

> The zipper should work on n-ary trees. all the zipper does is
> store the tree as (Context,Subtree)

What is the meaning of storing in haskell?
Imagine I put numbers in the leaves...
> you could do something like
> data Context x = Root | Parent x (Context x) [Rose x] [Rose x]
> data Rose x = Node x [Rose x]
Should the numbers be of type x ,right?? So x is Int.
    -5
    |
  -2-6
  |
1-3
  |
  -4

context of 1 is Root.Where do I store the 1?I Subtree?The name is 
misleading me...
context of 2 is Parent 1 Root .....and then

To make it easy I don't mind siblings I just want sons


> so at any given point in the tree the context is either Root,
> or the Parent (with the value at that node, the parents context,

What do you mean with the parents context?Is it the substitution for the 
pointer?
Which is the tracker function?

tracker (context,???)
	| (Root,???) = [kkkk] kkkk should be the node 1 where can I get it?
	| (Parent p (Contetx c)....,???) = tracker (c,?!?):kkkk

I feel terrible ........   Paolino

						










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