[Zope3-dev] Re: proposal: replace zope.schema.Sequence with zope.schema.Collection

[Philipp von Weitershausen]

Fred Drake wrote:
>  > IMO, Stephan has identified a clear place in which our model could be
>  > improved.  Rather than merely making ISet not subclass ISequence (and
>  > make it just subclass IField, I suppose), I propose that
>  >
>  >     * "Sequence" be renamed to "Collection" (and "ISequence" to
>  >       "ICollection");
>  >     * "Collection" include an "ordered=True" keyword argument;
>  >     * "List" and "Tuple" subclass "Collection" (and same for interfaces)
>  >       and disallow setting of "ordered" (it must always be True);
>  >     * "Set" subclass "Collection" (and same for interfaces) and disallow
>  >       setting of "ordered" (it must always be False); and
>  >     * (less importantly) "Set" default to creating a Sets.set.
> 
> I just spoke with Gary, and am proposing a slight modification of this change:
> 
> - Collection is added as a base for Sequence (and ICollection for ISequence)
> 
> - Sequence will set ordered=True and disallow changing it
> 
> - List and Tuple subclass Sequence

This also makes more sense to me, although this will result in some deep 
inheritance chains just for fields. It might confuse people. OTOH, it 
just makes sense :)

Philipp