From: Brian Candler <B.Candler@...>
Date: 2003-03-27T23:10:16+09:00
Subject: Re: What are the differences between Ruby's blocks and Python's lambdas?

On Thu, Mar 27, 2003 at 10:03:14PM +0900, ts wrote:
> B> class <<a; end
> 
>    # class <<a; end   # useless

I tried 'class <<a; def zzz; end; end' but it doesn't help.

Let me ask the question in a different way. This is what I want to do: add a
singleton method to an existing object, bound to a proc object in local
scope.

  a = Foo.new

  pp = proc { |x| x+1 }
  def a.foo(*args)             # create a singleton method of 'a'
    pp.call(*args)             # doesn't work
  end

  a.foo(10)

But I can't do it like that, because the local variable pp goes out of scope
as soon as you go inside 'def'. pp is a Proc so it can't be inserted
usefully into string eval, as far as I can see.

Is there a solution? I think I want 'define_singleton_method' but it doesn't
seem to be there. I should probably install 1.8 preview and see if it's been
added.

Regards,

Brian.