- From: Jeni Tennison <jeni@jenitennison.com>
- Date: Thu, 13 Apr 2006 20:44:11 +0100
- To: public-xml-processing-model-wg@w3.org
Hi, [Having read the minutes of the telcon.] I don't think that no side effects impacts on whether caching is allowed or not. A component with side effects can consistently produce the same side effects each time, after all. Rather, whether or not we allow side effects is important when considering reordering steps, or skipping them altogether. I'm in favour of a "no side effects" rule because I want to make sure that the same pipeline run at the same time on different pipeline engines produces the same result. I view that as the basis for interoperability, which is one of our design principles. I also want pipeline engines to be able to optimise, such as by not performing steps that don't need to be performed or by performing steps in parallel. I don't want those optimisations to effect the final result. I therefore think it's vital that if the pipeline language doesn't constrain a pipeline engine to run two steps in a particular order then the order in which the two steps are run doesn't have an effect: the steps have no side effects. Cheers, Jeni -- Jeni Tennison http://www.jenitennison.com
Received on Thursday, 13 April 2006 19:44:21 UTC