Class: Object

Inherits:
BasicObject
Defined in:
lib/plucky/extensions/duplicable.rb

Overview

Copyright © 2005-2010 David Heinemeier Hansson

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Most objects are cloneable, but not all. For example you can’t dup nil:

nil.dup # => TypeError: can't dup NilClass

Classes may signal their instances are not duplicable removing dup/clone or raising exceptions from them. So, to dup an arbitrary object you normally use an optimistic approach and are ready to catch an exception, say:

arbitrary_object.dup rescue object

Rails dups objects in a few critical spots where they are not that arbitrary. That rescue is very expensive (like 40 times slower than a predicate), and it is often triggered.

That’s why we hardcode the following cases and check duplicable? instead of using that rescue idiom.

Instance Method Summary collapse

Instance Method Details

#duplicable? ⇒ Boolean

Can you safely .dup this object? False for nil, false, true, symbols, numbers, class and module objects; true otherwise.

Returns:

  • (Boolean) 


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# File 'lib/plucky/extensions/duplicable.rb', line 41

def duplicable?
  true
end