simple dispatcher using method_missing in Ruby

dispatcher.rb

class Dispatcher
  
  # Remove the cruft to try to keep the options clear
  instance_methods.each { |m| undef_method m unless m =~ /^__|instance_variable_?e?|object_id|inspect|dup/ }
  
  # Store the callback and initialize the route
  def initialize(&block)
    @route = []
    @block = block
  end
  
  def chain(name, *args)
    @route = @route + [name]
    if args.length > 0
      @block.call(@route, *args)
    end
    if block_given?
      yield(@route, *args)
    end
    self
  end
  
  # Keep building the route on duped copied of self 
  def method_missing(*args, &block)
    self.dup.chain(*args, &block)
  end
end

a = Dispatcher.new do |route, *args|
  p "Route #{route.inspect} message #{args.inspect}"
end

log = lambda { |*args| p args }

a.b(:hi).c(:cool).d.e.f :GO, :param2
a.b(1,2,3,&log).c(&log).d{|route|p route}.e.f.g.h.i.j.k.l do |route|
  p route
end

# Sample output
#
# "Route [:b] message [:hi]"
# "Route [:b, :c] message [:cool]"
# "Route [:b, :c, :d, :e, :f] message [:GO, :param2]"
# "Route [:b] message [1, 2, 3]"
# [[:b], 1, 2, 3]
# [[:b, :c]]
# [:b, :c, :d]
# [:b, :c, :d, :e, :f, :g, :h, :i, :j, :k, :l]