From: Robert Klemme <bob.news@...>
Date: 2005-09-20T00:01:37+09:00
Subject: Re: help with tricky proc/binding issue

Ara.T.Howard wrote:
> i'm trying to be able to define a proc that can be called in the
> context of self, eg:
>
>    block = lambda{ p 42 }
>    an_obj.instance_eval &block
>
> but which can also be called with arguments, for example (imaginary
> ruby):
>
>    b = lambda{|x| p [x, y]}
>
>    class C
>      def y; 42; end
>    end
>
>    c = C::new
>    x = 42
>
>    c.arg_instance_eval(x, &b)  #=> [42, 42]
>
> any ideas?

The only workaround that comes to mind is to pass self explicitely along
with other arguments.  Or use a trick with delegation that allows to do
instance_eval on a proxy self that will also provide arguments given.

    robert