What you write (down below) is close to what I was thinking when I  
said have all #isXXX return false by default;
although I would test that the first two characters match 'i' and 's'  
and that more characters exist, if so, return false, otherwise, normal  
#doesNotUnderstand: behavior.

I would treat #is by itself differently... it is ... or it couldn't be  
tested! So I would do nothing for simple #is. and I don't like #is:  
because it looks like a class type test... but that is part of the  
point, eh?

I'll have to go back to the original example (by siguctua at gmail.com,  
and read more about lambdas) but I thought that CVLambda would  
implement #isCVLambda  to return true when it can be verified to be  
one. The example did not illustrate #doesNotUnderstand:.

Back to the question of adding behavior to classes that you don't own.  
VisualWorks has a means to extend a class in a different package ...  
as I recall. As I recall, squeak has no such capability, right?

Thanks. You have given me food for thought...

Ciao,
Cam

On Jun 29, 2009, at 3:43 PM, David Goehrig wrote:

> What I typically what I've been doing to eliminate all of these  
> methods with a single simple change:
>
> Object
>    doesNoUnderstand: aMessage
>        ^ false