- From: Cullen Jennings (fluffy) <fluffy@cisco.com>
- Date: Tue, 3 Dec 2013 16:38:24 +0000
- To: Jim Barnett <Jim.Barnett@genesyslab.com>
- CC: "public-media-capture@w3.org" <public-media-capture@w3.org>
I find these emails very hard to follow but I don't like the new syntax. On Nov 27, 2013, at 8:55 AM, Jim Barnett <Jim.Barnett@genesyslab.com> wrote: > I prefer the current syntax. It is more compact and makes back-off easier. Furthermore, it makes the semantics of ‘best effort’ values like min/max/mid easy to understand, at least in the case of optional constraints. Suppose we have optional constraints “prop1 max, prop2 max, prop3 max”. This would mean: set prop1 to the largest value you can, the set prop2 to the largest value you can without changing prop1, then set prop3 to the largest value you can get without changing prop1 or prop2. The ordering of the constraints specifies the ordering of the optimizations. > > The use of max/min/mid in mandatory constraints is trickier, because mandatory constraints are unordered. But it’s not clear that these values are useful in mandatory constraints, given that their semantics has to be something like: any value that the UA picks satisfies the constraint, but the UA SHOULD pick the largest/smallest/middlingist value that it can find. So in mandatory constraints max/min/mid will never fail, and the app won’t be able to control the order in which they are applied (that’s up to the UA). It’s harmless to use these values in mandatory constraints, but sophisticated developers will realize that they work better as optional constraints. > > - Jim
Received on Tuesday, 3 December 2013 16:38:56 UTC