- From: Lucas Gonze <lgonze@panix.com>
- Date: Wed, 10 Jan 2001 14:23:49 -0500 (EST)
- To: Henrik Frystyk Nielsen <frystyk@microsoft.com>
- Cc: Hugo Haas <hugo@w3.org>, Noah Mendelsohn <Noah_Mendelsohn@lotus.com>, Martin Duerst <duerst@w3.org>, <xml-dist-app@w3.org>
> How > would the server find out that M and L are in fact substitutable? This is doable if there is an object hierarchy. If M is a class of message handler that is derived from L, so that its functionality is a superset of L's, the the message can be treated polymorphically depending on context. This is the approach we took with the WorldOS internal protocol and it has worked out quite well. It takes an OOP approach to object binding and applies it to node binding. The main impact is in using intermediaries, since you can have a complex chain of proxies, each with different capabilities. A usecase is with different versions of a protocol. Message M contains an XP v2 envelope, and it is derived from message L, which contains an XP v1 envelope. To make this work all you have to do is assure that * extensions made in v2 don't break v1. * v1 forwarders can pass on the message without losing the v2 characteristics. * a node which receives a message can figure out enough about the derivation tree to make a sensible decision. - Lucas Gonze
Received on Wednesday, 10 January 2001 14:25:56 UTC