On 13-Jul-08, at 1:01 PM, Janko Mivšek wrote:

> Hi Colin,
>
> Colin Putney wrote:
>
>>> I'm willing to migrate to such MC immediately if available. I think
>>> working with overrides is such a powerful feature (not to mention  
>>> that
>>> VisualWorks have that) that Squeak needs the proper support as  
>>> soon as
>>> possible.
>> MC2 doesn't have a concept of overrides as such, but it does allow  
>> packages to overlap, and uses versioning history to determine which  
>> of the two versions of a method should be used.
>> I'm doing the final clean up for the first release, which will be  
>> Real Soon Now™.
>
> That means if I extend some method in another package and it happens  
> that the method has the same name (this is regarded as override in  
> VW for nistance), MC2 will deal with that situation right and won't  
> change an original package as that this method is removed there?

Right, more or less.

There's really no distinction between "orignal package" and  
"overriding package." Only one variant of the method can be loaded at  
a time, but both packages will consider the method to be part of the  
package.

A common case will be wanting to change a method in another package.  
Say I have a web app in AIDA/Web, and I want to change on of the base  
methods. I add the method to my package, and make my change. When I  
save a snapshot of my web app, it'll include the history of that  
method, and as long as the base version doesn't change, my version  
will supersede it. But if you then change the method in AIDA/Web, I'll  
get a conflict when I load my web app, which I'll have to resolve, by  
choosing your new version, my existing version, or some new version  
that I write taking both into account.

Colin