Philipp von Weitershausen wrote at 2006-9-30 02:30 +0200: > ... >> You want to stick this interface to individual objects, >> while Lennart proposed to stick it to a type and use >> some kind of inheritance to make it effective on all objects >> instantiated from this type. > >But where does this type come from? Persistent classes are hard (hence >ZClasses cannot be maintained by anyone except a few people).
I remember that Jim proposed "PersistentModule"s, currently a ZODB proposal, to implement functionality similar to ZClasses in an easier way. But, I cannot yet answer your question sincerely. >> For me, Lennart's approach seems to be far more economic, as >> he does things on an abstract (the type) level rather than >> always work on the concrete (the individual object) level. > >I don't see how introducing another concept (a type) would be more >economic. I find that the introduction of classes with (multiple) inheritance has been very economic. It was another concept but a highly fruitful one, despite the fact that they are not so liked in Zope3 land. As a former mathematician, I also like the introduction of abstraction layers (object -> type/class -> metatype/metaclass -> ...) as abstraction often drastically increases economicity. >It'd be one more thing to worry about wrt persistency etc. Your answer to Lennart made me a bit unsure. It appears as if an interface could live on different abstraction levels -- at least together with ZCML and adapter magic. I am not yet really familiar with this. Let's see what Lennart answers. -- Dieter _______________________________________________ Zope-Dev maillist - Zope-Dev@zope.org http://mail.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope )
