Yet another example of implementing something LIKE refinements directly in pure ruby. I run into the contraint of being unable to properly set 'self' in my blocks. (could be solved if I had https://bugs.ruby-lang.org/issues/8465) AND, it's very hacky because it uses caller. but I *think* this is what @Shogu generally intends the semantics of blo…

alternate_refinements.rb

class BlockRefinement

  def self.refines(*classes_refined)
    @classes_refined = classes_refined
  end

  def self.refines_method(method_refined, &new_method)
    @classes_refined.each do |class_refined|
      old_method = class_refined.instance_method(method_refined) 
      @reverts ||= []
      @reverts << Proc.new do
        class_refined.instance_eval do
          define_method(method_refined, old_method)
        end
      end
      @applies ||= []
      @applies << Proc.new do |limit_context_to|
        class_refined.instance_eval do
          define_method(method_refined) do |*args|
            if caller[0].include?(limit_context_to.to_s)
              new_method.call(self, *args)
            else
              bound = old_method.bind(self)
              bound.call(*args)
            end
          end
        end
      end
    end
  end

  def self.using_refinement(&context)
    @limit_context_to = context.binding.eval("self")
    @applies.each{|a| a.call(@limit_context_to) }
    yield
  ensure
    @reverts.each(&:call)
  end

end

class MathRefinement < BlockRefinement
  refines Float, Fixnum, String
  refines_method(:*) do |realself, arg|
    "(#{realself.to_s}) * (#{arg.to_s})"
  end
  refines_method(:+) do |realself, arg|
    "(#{realself.to_s}) + (#{arg.to_s})"
  end
end

class Elsewhere
  def self.calculate_a_thing
    5 + 5
  end
end

class MyDSL
  class << self
    attr_accessor :things
  end
  self.things = []
  MathRefinement.using_refinement do
    self.things << 3.14159 * 5 + 10 * Elsewhere.calculate_a_thing
  end
end

puts 3.14159 * 5 + 10 * Elsewhere.calculate_a_thing

puts MyDSL.things.inspect

puts 3.14159 * 5 + 10 * Elsewhere.calculate_a_thing