1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
|
module Kernel
# Adds deep_clone method to an object which produces deep copy of it. It means
# if you clone a Hash, every nested items and their nested items will be cloned.
# Moreover deep_clone checks if the object is already cloned to prevent endless recursion.
#
# obj = []
# a = [ true, false, obj ]
# b = a.deep_clone
# obj.push( 'foo' )
# p obj # >> [ 'foo' ]
# p b[2] # >> []
#
# CREDIT: Jan Molic
def deep_clone( obj=self, cloned={} )
if cloned.has_key?( obj.object_id )
return cloned[obj.object_id]
else
begin
cl = obj.clone
rescue Exception
# unclonnable (TrueClass, Fixnum, ...)
cloned[obj.object_id] = obj
return obj
else
cloned[obj.object_id] = cl
cloned[cl.object_id] = cl
if cl.is_a?( Hash )
cl.clone.each { |k,v|
cl[k] = deep_clone( v, cloned )
}
elsif cl.is_a?( Array )
cl.collect! { |v|
deep_clone( v, cloned )
}
end
cl.instance_variables.each do |var|
v = cl.instance_eval( var )
v_cl = deep_clone( v, cloned )
cl.instance_eval( "#{var} = v_cl" )
end
return cl
end
end
end
end
|
