It would be nice to be able to pass a block to a service point that has been registered.  Say for example you have some
class that needs to write to a file (yes, this is a silly example but hopefully simple enough to be clear):

class MyClass

 def do_something_to_a_file
    REGISTRY.file("my_file") do |file|
      ...
    end
 end
end

And in your services.rb file:

  REGISTRY = Needle::Registry.new

  REGISTRY.register(:file, :model => :prototype) do |container, point, file_name,  block|
    if block.nil?
       File.open(file_name)
    else
       File.open(file_name, &block) 
    end
end

Not sure what the best way to do this is...but one approach is as follows:


1.  Update container::method_missing( sym, * args, &block )
2.  Update container::get( name, *args, &block )
3.  Update service-point::instance( *args, &block )
4.  And then the call method in multiton (andother similar classes):

      def call( container, point, *args, &block )
        unless @is_cached[ args ]
          @mutex.synchronize do
            unless @is_cached[ args ]
              a_proc = Proc.new(&block)
              args.push(a_proc)
              @cached[ args ] = succ.call( container, point, *args)
              @is_cached[ args ] = true
            end
          end
        end