- From: Hugo Haas <hugo@w3.org>
- Date: Fri, 5 Jan 2001 14:36:06 +0100
- To: Henrik Frystyk Nielsen <frystyk@microsoft.com>
- Cc: "Martin J. Duerst" <duerst@w3.org>, xml-dist-app@w3.org
On Wed, Dec 20, 2000, Henrik Frystyk Nielsen wrote: > > R700b: This seems to be thinking only about indepenent extensions. > > Despite trying hard, in many cases extensions are not > > independent. > > It should be possible to express e.g. that the message is > > successful if either extensions A and B OR extensions C and D > > are known. This can not be expressed with a simple mandatory/ > > optional distinction. > > The requirement should make clear what combinations are > > needed, and should include combinations as described above. > > The problem with negotiation is that it can only be done within a > context. In other words, in order to negotiate, you need to know what > you are negotiating. As the purpose of XP is to *not* know about any > particular area (which can be expressed as an XP module) all we need is > a single optional/mandatory bit. That allows for any negotiation, logic > language or dependency language to be expressed in a layer or layers > above (neither of these are described by the charter btw.). That is, by > having a single bit XP can support the model you describe but XP doesn't > have to define it. I am not sure that it is really a negotiation problem. I do not see much difference between "must deal with A" and "must deal with A or B". I think that it is more a simplicity problem. An optional/mandatory bit is easy to define; a combination of and's and or's is more complex to represent and process. -- Hugo Haas - W3C/MIT mailto:hugo@w3.org - http://www.w3.org/People/Hugo/ - tel:+1-617-452-2092
Received on Friday, 5 January 2001 08:36:13 UTC