= DeepDive Deep Contolled Cloning

When you have a system of objects that have many references to each other, it becomes an
issue to be able to clone properly that object graph. There may be control objects you may
not want to clone, but maintain references to. And some references you may not wish to clone at all.

Enter DeepDive. Allows you a means by which you can do controlled deep cloning or
copying of your complex interconnected objects.

== Gem Version
{<img src="https://badge.fury.io/rb/deep_dive.png" alt="Gem Version" />}[http://badge.fury.io/rb/deep_dive]

== Usage
Simply include DeepDive in your base class. All classes derived will be set
for deep cloning or deep duping.

== Examples

 class FooBase
   include DeepDive
   exclude :c
 end

Even though the instance variable @c is not defined in the base class, any instance
variables with that name in the subclasses will be excluded from the deep clone or duping.
It will simply use the reference to that object instead (a.k.a shallow copying)

 class Foo < FooBase
   attr_accessor :a, :b, :c, :changeme
 end

 class Bar < FooBase
   attr_accessor :a, :b, :c, :changeme
 end

 class FooBar < FooBase
   attr_accessor :a, :b, :c, :changeme, :dontcopy, :arr, :hsh, :nonddob
   exclude :dontcopy
 end

 class FooBlock < FooBar
   attr_accessor :freject, :fa, :fb, :fc, :frecur, :fexcludeme
   exclude { |sym, obj|
     sym == :@fexcludeme if obj.instance_variable_defined?(:@freject) and obj.send(:freject)
   }
 end

 @foo = Foo.new
 @bar = Bar.new
 @foobar = FooBar.new
 @foobar.arr = [@foo, @bar, @foobar, "Just a string"]
 @foobar.hsh = {foo: @foo, bar: @bar, foobar: @foobar, nonddob: "just a string"}

 @foo.a = 'foo just around'
 @bar.a = 'bar hanging around'
 @foo.b = @bar
 @bar.b = @foo
 @foo.c = @bar.c = @foobar.c = @foobar
 @foo.changeme = @bar.changeme = @foobar.changeme = "initial"

So now if you do:

 nfoo = @foo.dclone

@foo.c will refer to the same object as nfoo.c,
but @foo.b and nfoo.b will be different, as nfoo.b will be a deep clone of @foo.b.

Also, you may do:
 mfoo = @foo.ddup

which will basically do a deep dup of @foo.

Please see spec/lib/deep_dive/deep_dive_spec.rb for a more comprehensve example
of the above. Better documentation will be supplied shortly.

== Note Well

DeepDive is expected to undergo rapid evolution until it hits 1.0.0. I will take
every effort to keep the API backwards compatable until then.

== Release Notes

2014-07-27 0.2.0 -- Implemented the exclusion block,
                    made gem restrictive to Ruby 2.x and higher.

== Copyright

Copyright (c) 2013-2014 Fred Mitchell. See LICENSE.txt for
further details.