Module: Configatron::DeepClone

Defined in:
lib/configatron/deep_clone.rb

Class Method Summary collapse

Class Method Details

.deep_clone(obj = self, cloned = {}) ⇒ Object

DeepClone

Version

1.2006.05.23.configatron.1 (change of the first number means Big Change)

Description

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.

Usage

(see examples directory under the ruby gems root directory)

 require 'rubygems'
 require 'deep_clone'

 include DeepClone

 obj = []
 a = [ true, false, obj ]
 b = a.deep_clone
 obj.push( 'foo' )
 p obj   # >> [ 'foo' ]
 p b[2]  # >> []

Source

simplypowerful.1984.cz/goodlibs/1.2006.05.23

Author

jan molic (/mig/at_sign/1984/dot/cz/)

Licence

You can redistribute it and/or modify it under the same terms of Ruby's license;
either the dual license version in 2003, or any later version.



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# File 'lib/configatron/deep_clone.rb', line 37

def self.deep_clone( obj=self, cloned={} )
  if Configatron::RootStore === obj
    # We never actually want to have multiple copies of our
    # Configatron::RootStore -- when making a temp, we just stick
    # the state-to-revert-to into an ivar.
    return obj
  elsif Configatron::Store === obj
    # Need to special-case this since it's a BasicObject, meaning it
    # doesn't respond to all the usual ivar magic methods
    cl = obj.clone(cloned)
    cloned[obj.__id__] = cl
    cloned[cl.__id__] = cl
    return cl
  elsif cloned.key?( obj.__id__ )
    return cloned[obj.__id__]
  else
    begin
      cl = obj.clone
    rescue Exception
      # unclonnable (TrueClass, Fixnum, ...)
      cloned[obj.__id__] = obj
      return obj
    else
      cloned[obj.__id__] = cl
      cloned[cl.__id__] = cl
      case
      when Hash === cl
        cl.clone.each do |k,v|
          cl[k] = deep_clone( v, cloned )
        end
      when Array === cl
        cl.collect! do |v|
          deep_clone( v, cloned )
        end
      end
      cl.instance_variables.each do |var|
        v = cl.instance_eval( var.to_s )
        v_cl = deep_clone( v, cloned )
        cl.instance_eval( "#{var} = v_cl" )
      end
      return cl
    end
  end
end