- From: C. M. Sperberg-McQueen <cmsmcq@blackmesatech.com>
- Date: Thu, 8 Dec 2016 09:12:26 -0700
- To: Abel Braaksma <abel.braaksma@xs4all.nl>
- Cc: "C. M. Sperberg-McQueen" <cmsmcq@blackmesatech.com>, Public XSLWG <public-xsl-wg@w3.org>
> On Dec 8, 2016, at 8:42 AM, Abel Braaksma <abel.braaksma@xs4all.nl> wrote: > ... > Furthermore, I like the idea that the specification would be written in such a way that it does NOT limit performance improvements, and I believe expression rewriting is a performance improvement that we should not discourage. I think that you are once again conflating the concepts of guaranteed streamability and streamability in fact. Given that the concepts are distinct, as they are in our spec (though not, it seems, in every WG member’s mind) how does the phenomenon you describe work? How does our definition of guaranteed streamability serve to encourage or discourage performance improvements in processors? Perhaps you are interpreting the proposition “Construct C is not guaranteed streamable” as meaning “Construct C should not be streamed” — but that’s not what it means. Or perhaps you are interpreting the proposition “The failure of construct C to be guaranteed streamable must be detected by a processor” to mean “The processor’s streamability analysis must detect the failure of a construct to be guaranteed streamable.” But that’s not what it means — it has been clear since 2007 at the latest that the definition of guaranteed streamability given in the spec will not necessarily be isomorphic to an implementation’s internal analysis of streamability (i.e. its analysis of streamability in fact), nor to part of it. It seems to me a fairly obvious consequence that the analysis of guaranteed streamability may then need to be carried out independently of a processor’s analysis of streamability in fact, at least in part. All of your arguments seem to rest on the premise that there should be no difference between guaranteed streamability and streamability in fact — that is, it seems to me that you are conflating the two concepts. Please stop doing so; it is becoming harder and harder for me to believe that you are doing so in good faith. The only news in this bug report appears to be that the two implementors in the WG have decided to say, now when the spec is on the verge of completion, that after all they don’t want to calculate guaranteed streamability independently of their analysis of streamability in fact. That this will tend to leave users dependent on the processor with which they initially develop a stylesheet is, I am sure, a wholly unintended consequence of a purely technical preference on the part of the implementors. That it seems a minor consequence is also clear: when has user lock-in to one’s own product ever bothered an implementor? ******************************************** C. M. Sperberg-McQueen Black Mesa Technologies LLC cmsmcq@blackmesatech.com http://www.blackmesatech.com ********************************************
Received on Thursday, 8 December 2016 16:13:01 UTC