From: Ammar Ali <ammarabuali@...>
Date: 2010-10-19T00:20:45+09:00
Subject: Re: Is it possible to find out if an identifier is a method alias?

On Mon, Oct 18, 2010 at 5:56 PM, Robert Dober <robert.dober@gmail.com> wrote:
> Maybe it is best to say that somehow it really does not matter, I
> would be curious to see where it matters. The following, completely
> useless code,  somehow demonstrates this:
>
> Class::new do
>  def a; end
>  alias_method :x, :a
>  remove_method :a
>  alias_method :a, :x
>  p instance_methods( false )
> end
>
> and the question I would like to ask is, what is :a in this case? An
> alias to itself after having been removed I guess ;).

If I understand how this works correctly, then remove_method is only
removing the :a entry for the method from the object's table, but
since there is another "reference" to the method definition (the b
alias, which is just another entry to same method), the body of the
method is not removed. Adding :a again is simply adding a new entry
for the same method. If both :a and :b are removed, then one tries to
add an alias a NameError would be raised.

Regards,
Ammar