W3C home > Mailing lists > Public > xproc-dev@w3.org > June 2009

streaming vs p:iteration-size()

From: Michael Sokolov <sokolov@ifactory.com>
Date: Wed, 3 Jun 2009 00:31:31 -0400
Message-Id: <200906030419.n534JnJY023577@hades.falutin.net>
To: "'XProc Dev'" <xproc-dev@w3.org>
I've been reading the xproc spec today.  I'm really excited, because I had
actually started implementing something with a similar flavor (with
pipelines and actions instead of pipelines and steps, but hey) and then
realized xproc was going to basically do pretty much everything that I
wanted, and save me lots of time, so thanks to all your all hard work,
specifiers and implementers!
Naturally I have some questions.. Now I hope these questions haven't all
been thrashed out in great detail on this list before, but I am catching up
and it was more than I could do to read *all* the posts, so please bear with
It seems as if support for streaming implementations was a major
consideration in the design of xproc.  I wonder if the requirement to
support p:iteration-size() in the context of p:for-each and p:viewport isn't
at odds with the ability to create a streaming implementation though.  For
example, wouldn't an implementation be required to count all the matches,
thus parsing the entire document, before processing any of them?
I haven't looked through any implementations to see what's going on there,
but this seems designed in to the spec anyway. Am I missing something?
Received on Thursday, 4 June 2009 10:25:11 UTC

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