Playing with duck-typed callables

inject_callables.rb

module Import
  module Translation

    @translators = {}

    def self.register(name, callable)
      if callable.respond_to?(:call)
        @translators[name.to_sym] = callable
      else
        raise Exception("Registered translators must be callable")
      end
    end

    def self.translate(translator, value)
      @translators[translator].call(value)
    end

  end
end

module Import::Translation
  class Reverse
    def self.call(value)
      value.reverse
    end
  end
end

class SomeClass
  def helper(value)
    value.reverse
  end
end

tr1 = Import::Translation::Reverse
Import::Translation.register(:tr1, tr1)
puts Import::Translation.translate(:tr1, "evian")

tr2 = SomeClass.new.public_method(:helper)
Import::Translation.register(:tr2, tr2)
puts Import::Translation.translate(:tr2, "koala")

tr3 = ->(value){ value.reverse }
Import::Translation.register(:tr3, tr3)
puts Import::Translation.translate(:tr3, "mongo")