From: Tomasz Wegrzanowski <taw@...>
Date: 2001-12-29T09:16:49+09:00
Subject: [ruby-talk:29604] Re: promoting self to subclass (was extending method of class A ...)

On Sat, Dec 29, 2001 at 01:01:35AM +0100, Mark Hahn wrote:
> Why not allow a method to "promote" it's object to a subclass of the object?
> I've wanted to do this before in ruby and Java.  It should be somewhat easy
> in ruby and nearly impossible in a static language.
> 
> How about making it:  self.promote(Klass)  or maybe Kernel::promote(Klass) ?
> The same code that does the promotion could set the extra instance
> variables.  Or, even better, the initializer of the subclass could be called
> with params from the promote call: self = Klass.new(*params).  In general
> this could be considered "assignment to self".
> 
> Where I've run into this need is when an initializer realizes that, based on
> input params, there is a more specific class for this data.  Another case is
> when an object is created and the "type" gets refined later.  If you want a
> specific example of this being used, let me know.

How can it be used in presented Real/Complex case ?