From: Trans <transfire@...>
Date: 2006-10-15T00:40:17+09:00
Subject: Re: What's wrong with my metaprogramming?

John Ky wrote:
> >>>>>
> def define_my_method(method_name)
>   define_method method_name do
>     yield
>   end
> end

Yea, funny thing about Ruby, closures go a long ways. Have a look at
what self is in one fo your definitions:

> class X
>   define_my_method :method1 do
>     puts "Method 1"
>   end
>   define_my_method :method2 do
>     puts "Method 2"
        p self
>     method1
>   end
> end
>
> X.new.method2

This is why define_method takes a block. So a fix would be:

  def define_my_method(method_name, &block)
    define_method method_name, &block
  end

Unfortuantely that's not always the prefect solution since you might
want to wrap extra code around the yield . In that case, you can use
#instance_eval if you don't need to pass parameters. If you do need to
pass parameters you'll have to use more complicated tricks until 1.9
introduces #instance_exec.

On a related note, I still think it would be helpful if we could create
clean-closure blocks.

T.