[Zope-dev] summary of discussion was: adapter vs factory Re: implementing zope.component 4.0

[Gary Poster]

On Dec 1, 2009, at 8:21 AM, Martijn Faassen wrote:

> Hi there,
> 
> I'd like to summarize the options I've seen appear in the discussion so far.
> 
> We have the following options:
> 
> 1) introduce a new method, such as "instance()" or "lookup()" on 
> instance. It unifies utilities with adapters. We can make it do whatever 
> we want without worrying about backwards compatibility.
> 
> 2) introduce several new methods that distinguish between utility and 
> adapter lookup. We can make them do whatever we want without worrying 
> about backwards compatibility.
> 
> 3) call the interface, which unifies adapter and utility lookups. Use 
> tuples for multi adaptation. We think could make this work without *too* 
> much backwards compatibility issues (pending research on how prevalent 
> tuple adaptation really is). In the long term we can even map out a 
> deprecation strategy that can smoothly migrate us to a "multi argument" 
> approach.
> 
> 4) call the interface, which unifies adapter and utility lookups. Use 
> multiple arguments for multi adaptation. The backwards compatibility 
> obstacles are largest here as we already have the "default" argument. 
> We'd need to introduce multiple "modes" to selectively upgrade.

You are leaving out the variants of 3 and 4 that allow calling the interface to support multiadaptation, but do not unify utilities.

My impression is that I am not the only one who is not pleased with the proposed unification of utilities and adaptation.

My impression is that we are nearing consensus on the variation of 3 that does not include utilities.

Gary