The Non-Virtual Interface idiom in D

[Michel Fortin]

On 2009-09-26 10:06:24 -0400, Andrei Alexandrescu 
<SeeWebsiteForEmail at erdani.org> said:

> Michel Fortin wrote:
>> I think you're writing a lot of boilerplate code for something that the 
>> compiler should be able to do by itself. I mean, it's a lot cleaner 
>> with contracts, and there is no reason the compiler couldn't generate 
>> itself that "contract-verifying" non-virtual function.
> 
> I think it would be a mistake to latch on my quick examples. It's not 
> only about before and after checks, it's more about low-level 
> customization points versus higher-level interfaces.

Then your examples should have shown this instead.

I fully support having a way to specify a default implementation for a 
function in an interface. It might get handy for a few things (like 
implementing the delegate pattern you see everywhere in Cocoa). But 
it's a bad replacement for contracts.

-- 
Michel Fortin
michel.fortin at michelf.com
http://michelf.com/