From: Eric Hodel <drbrain@...7.net>
Date: 2008-02-28T05:01:44+09:00
Subject: Re: Question about how ruby sources is parsed

On Feb 27, 2008, at 07:19 AM, ThoML wrote:
> I recently came came up with this piece of (monkey-inspired) code:
>
>    class String0 < String
>        def foo
>            123
>        end
>    end
>
>    Object.send :remove_const, :String
>    String = String0
>
> This makes the following two statements work as intended:
>
>    p String0.new("foo").foo # => 123
>    p String.new("foo").foo # => 123
>
> The following doesn't work though:
>
>    p "foo".foo
>    p eval %{"foo".foo}
>
>    undefined method `foo' for "foo":String (NoMethodError)
>
> Has somebody an idea if it is possible to make the ruby parser use
> the new String class somehow? I assume there is no way to make this  
> work
> but then: I'd be happy if somebody proves me wrong.

You can't do this without modifying the interpreter.