Refinements
Refinements
Due to Ruby's open classes you can redefine or add functionality to existing classes. This is called a “monkey patch”. Unfortunately the scope of such changes is global. All users of the monkey-patched class see the same changes. This can cause unintended side-effects or breakage of programs.
Refinements are designed to reduce the impact of monkey patching on other users of the monkey-patched class. Refinements provide a way to extend a class locally.
Here is a basic refinement:
class C
def foo
puts "C#foo"
end
end
module M
refine C do
def foo
puts "C#foo in M"
end
end
end
First, a class C is defined. Next a refinement for C is created using Module#refine. Refinements only modify classes, not modules so the argument must be a class.
