[Zope-dev] A summary of "Interfaces vs ZCA concepts"

[Thomas Lotze]

Chris McDonough wrote:

> I'll throw out the obvious...
> 
> Why not subclass Interface in zope.component and make the required API
> additions there?  If it were anybody but us thinking about doing this,
> they'd probably just subclass.

Because then, if you use third-party code that uses
zope.interface.Interface and other code (third-party or your own) that
uses the subclassed interfaces, you'll have to deal with both types at the
same time in your client code. You could use the new API on some
interfaces but not on others, possibly on the same line of code. How
readable or maintainable would such code be?

-- 
Thomas