Arthur G. Duncan a �crit dans le message <3A02DF9B.2269@global2000.net>... >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 thanks for the help Duncan, but i'm new to Ada and recursivity, and i don't understand all you speek about ;o) what is a set of nested tuples?? there is no cycle i think in my program it s to make a genealogic tree,like this : father father has 2 children : child1 and child2 / \ / \ null child1 child1 has no child / \ / \ child2 null child2 has 2 children : little child1 and little child2 / \ / \ null little child1 little child1 has no child (right) and one brother(left) / \ / \ little child2 null little child2 has no other brother and no child / \ / \ null null i can easily save that in a files with recursive procedure, but i don't see how to load it from files still in need of help ;o) Franck