From: Mark Probert <probertm@...>
Date: 2002-10-30T04:23:18+09:00
Subject: problem with recursive structure


Dear Rubists,

I have a little class called SimpleTree that makes a recursive
data structure of arrays.  I am getting some funny behaviour when
I traverse the tree for printing.

The print routine is:

     def pp_branch(b)
         puts "(head) #{b[0]}"
         b.each { |item|
             next if item == b[0]        # avoid the head
             pp_branch(item) if item.type == Array
             puts "(leaf) #{item}"
         }
     end

Output looks like:

["a", "b", ["z/", "a", "b", ["y/", "c", "d"], "e"]]
(leaf) a
(leaf) b
(head) z/
(leaf) a
(leaf) b
(head) y/
(leaf) c
(leaf) d
(leaf) y/cd
(leaf) e

It is the line "y/cd" that gets me.  Ruby (or is it me?) appears
to be flattening included array "y".

Anyone help me with this?
TIA,



-mark

-----
Mark Probert
GNPS - Optera Metro 3000
Tel (613) 768-1082 (ESN: 398-1082)
Mob (613) 715-2045
email: probertm@nortelnetworks.com