From: Kjetil Orbekk <kjetil@...>
Date: 2006-12-26T23:11:18+09:00
Subject: YAML problem with serializing of nested object structures

Hi!

I'm making a graph tool, and i have some problem with the
serialization of my graphs. The problem comes when i try to load a
graph i earlier serialized with YAML. In the objects i serialize, I
have two instance variables (arrays, as below) that contain some other
objects of similar type (also serialized). I managed to reproduce the
problem with a simpler object structure below. To me, this seems very
wierd, especially since it saves some data and breaks it when
loading. Could it be a bug, or am I doing something wrong here?

ruby --version is "1.8.4 (2005-12-24) [i486-linux]". My operating
system is Debian GNU/Linux 4.0.

Ruby code:
----------

require "yaml"

# Test class with two instance variables to hold arrays with similar
# objects
class Test
  attr_accessor :c1, :c2
  def initialize(c1=[], c2=[]) @c1, @c2 = c1, c2 end
end

a = Test.new
b = Test.new([a],[Test.new])
a.c1 << b
a.c2 << b

# The problem comes when saving the whole thing as an array
ary = [a, b]

yaml1 = YAML.dump(ary)

# +ary_from_yaml[0]+ looses its c2 even though it's clearly in the YAML output
ary_from_yaml = YAML.load(yaml1)

yaml2 = YAML.dump(ary_from_yaml)

print "YAML 1\n" + yaml1 + "\n\n"
print "YAML 2\n" + yaml2 + "\n\n"

print "YAML 1 length: #{yaml1.length} \tYAML 2 length: #{yaml2.length}"


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