local_rebinding_visual.rb

# An attempt at visualising classbox local rebinding as described in
# http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.3.4133&rep=rep1&type=pdf
#
# Suppose a classbox ClassBox1 defines a class C with two methods, m callin n, and
# classbox ClassBox2 imports C from ClassBox1 and replaces n. We say that…

class C;end

module ClassBox1
  refine C do
    def m
      n
    end
    
    def n
      'ClassBox1'
    end
  end
end

module ClassBox2
  using ClassBox1
  refine C do
    def n
      'ClassBox2'
    end
  end
end


# …ClassBox2 locally rebinds n in ClassBox1 to represent the fact that calling m in the 
# context of ClassBox2 invokes the method n as defined in ClassBox2 while calling m in 
# the context of ClassBox1 invokes the method n as it is defined in ClassBox1.