require 'rubygems'
require 'parse_tree'
require 'sexp'
class UnboundMethod

  def binding_class
    @class_name || @class_name = begin
      to_s =~ /\#\<UnboundMethod\:\s(\w+)/
      Object.const_get($1)
    end
  end

  def name
    @name || @name = begin
      to_s =~ /\#\<UnboundMethod\:\s\w+\#(\w+)/
      $1.freeze
    end
  end

  def parameters
    @parameters || @parameters = begin
      params, sexp = [], Sexp.from_array(ParseTree.new.parse_tree_for_method(binding_class, name))
      sexp.each_of_type(:args) {|a| params = a.sexp_body.to_a }
      params
    end
  end

end

class Application < Merb::Controller

  def self.inherited(base)
    super
    memo = Hash.new() { |h,k| h[k] = base::instance_method(k).parameters }
    base.instance_variable_set("@parameters_for_action", memo)
  end

  def self.parameters_for_action(action)
    @parameters_for_action[action]
  end

  def call_action(action)
    send(action, *self.class::parameters_for_action(action).map { |name| params[name] })
  end

end