On Sunday, May 4, 2003, at 11:56  AM, Anthony Hannan wrote:

> There are
> many benefits to capturing interfaces and few costs.  Interfaces add
> structure explicitly defining module boundaries.  It also facilitate
> type inference.

Well, as an Objective C progammer, I have to agree.  While Objective C 
is as dynamically typed as Smalltalk (it can be a little more typed but 
its the programmer's choice), there are protocols and the lovely method 
on NSObject>>conformsToProtocol: which lets you know that this object 
implements all of the methods defined in a particular protocol (or 
interface if you like) which gives you some interesting info on 
substitutability pretty quickly.

I like protocols for this reason.

-Todd Blanchard