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From: "Arthur G. Duncan" <aduncan@global2000.net>
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Subject: Re: binary tree and files
References: <8tuk7l$aq5$1@wanadoo.fr> <8tul32$c3p$1@wanadoo.fr>
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Date: 2000-11-03T15:53:02+00:00
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Franck wrote:

  ... question on how to save and restore a binary tree of the 
      form: 

> type T_node;
> type Pt_tree is access T_Node;
> 
> type T_Node is record
>    name : T_name;
>    G, D : Pt_tree;
> end record;
> 

If it is, indeed, a tree (no cycles), you can simply write it out
as a set of nested tuples (LISP list notation is as good a form
as any).

If there are cycles (or the tree is reentrant and you want to save
disk space) you can label the nodes and write out label references
wherever you have a pointer in the original data structure. 

Hope this helps,

- Art Duncan
  aduncan@global2000.net