- From: Norman Walsh <Norman.Walsh@Sun.COM>
- Date: Fri, 07 Apr 2006 16:49:27 -0400
- To: public-xml-processing-model-wg@w3.org
- Message-ID: <873bgp5cx4.fsf@nwalsh.com>
See also: http://www.w3.org/XML/XProc/2006/04/06-minutes.html
W3C[1]
- DRAFT -
XML Processing Model WG
6 Apr 2006
Agenda[2]
See also: IRC log[3]
Attendees
Present
Alessandro, Andrew, Henry, Mohamed, Norm, Rui
Regrets
Erik, Jeni, Michael, Richard, Paul
Chair
Norm
Scribe
Norm
Contents
* Topics
1. Accept this agenda?
2. Accept minutes from the previous teleconference?
3. Next meeting: 13 Apr telcon
4. Publication status
5. Face-to-face meeting: 2-4 August 2006, north of Toronto
6. Starting a working draft
7. Richard's proposal
8. Conditionals and sub-pipelines
9. What about XPath 1 vs. XPath 2?
10. Any other business?
* Summary of Action Items
----------------------------------------------------------------------
Accept this agenda?
-> http://www.w3.org/XML/XProc/2006/04/06-agenda.html
Accepted.
Accept minutes from the previous teleconference?
-> http://lists.w3.org/Archives/Public/public-xml-processing-model-wg/2006Mar/0069.html
Accepted.
Next meeting: 13 Apr telcon
Any regrets?
No regrets given
Publication status
Norm submitted the transition request and got approval.
Norm submitted the publication request dated 11 Apr 2006
-> http://www.w3.org/XML/XProc/docs/WD-xproc-requirements-20060411/
Face-to-face meeting: 2-4 August 2006, north of Toronto
Norm proposes: who can commit to attending?
Rui: unsure; Norm: yes; Alessandro: unsure (also for Erik); Henry: yes;
Mohamed: unsure, but probably; Andrew: no; Paul: yes; Henry says Alex,
Michael, Jeni say yes; Richard: unsure
Tally: 7=yes; 5=unsure; 1=no
Proposed: we will meet in Toronto on the dates specified.
Accepted.
Henry points out that formally we can't decide to do this, all we can do
is ask the CG to allow us. No one seriously expects the CG to say anything
but "yes"
<scribe> ACTION: Norm to get this into the CG calendar [recorded in
http://www.w3.org/2006/04/06-xproc-minutes.html#action01[7]]
Starting a working draft
The chair asks if we have a volunteer editor.
Norm volunteers.
Norm warns that editing, chairing, and taking minutes may prove too much
for one person. He suggests that Henry, Michael, and perhaps others may
get called upon to take minutes.
Norm wonders if rotating the minute taking is the right thing.
Richard's proposal
-> http://www.cogsci.ed.ac.uk/~richard/pipeline.html
Norm wonders if it makes sense to consider Jeni's proposal of passing URIs
instead of documents around.
Henry doesn't think passing filenames (URIs) around is really going to
work.
Henry: Jeni's story could be read either way (as passing filenames or
using filenames)
... I'm still interested in thinking about this in terms of giving local
names to things (inputs/outputs) and using those names to refer to them.
Norm: With respect to giving names to local things, did you mean inputs
and outputs
Henry: Yes, but I also mean static resources/secondary inputs/whatever you
want to call them.
... In the pure piped ontology which Richard offered at the f2f, there is
a qualitative difference between an XSLT component that has one pipe
coming in and one going out and a parameter which is the name of a static
stylesheet and an XSLT component that has two pipes coming in and one
going out.
Norm: My proposal, to unify these, is to allow a shortcut for a
"read-from-URI" component that attaches to the stylesheet input pipe.
... Do you see any problem with that approach?
Henry: No, but I'm still swinging back and forth between thinking of the
pipeline runtime as a resource manager and the pure dataflow model.
Norm: I tend to swing back and forth as well. I hope that we don't have to
pick one.
... The resource manager view has the problem of dealing with a pipe that
contains a sequence of otherwise anonymous docments.
Henry: Local names are just conveniences. They are single documents or
doucment streams as appropriate.
... The only interesting case is when you use a non-local name.
... In MT pipe, the convention is if you use a #-ed name, it just plugs
together. If however it's a primary input/output connection and you give
it a non-#'d name, then you get the single document if it's one or the
last document if it's a sequence.
... There's no clear answer to the question of what does the label mean if
a sequence of documents is addresed by a lable in the resource-manager
view.
Norm ponders the idea of a resource manager that handles a collection
Norm suggests the fragment question as a next reasonable point to discuss
Norm describes the situation as an interoperability issue (since some
implementations might not even notice and others might fall over)
Henry: It's entirely reasonable for some implementations to fall over if
you pass anything other than real XML "Document"s .
Norm expresses a view that either the pipeline author has to fix it, or
the pipeline engine has to fix it.
Norm: I suggest for V1 that we say it's the pipeline author's problem
Henry: works for me
Norm wonders if the rest of the group agrees
Rui: I believe that just documents is good enough for me.
No one objects.
Proposal: only XML 1.x documents (proper Documents in the XML sense) pass
between components; if you need to pass something else in your pipeline,
the pipeline author has to wrap and unwrap as necessary.
Accepted.
<scribe> ACTION: Norm to begin summarizing the points of consensus
[recorded in http://www.w3.org/2006/04/06-xproc-minutes.html#action02[9]]
Conditionals and sub-pipelines
Norm: Richard proposed a single standard conditional that takes a document
and an XPath, is that enough?
Norm wonders if the WG thinks that's all we need
Henry: If you need something really complicated, you can write an
arbitrarily complicated computation that produces a document.
... And then switch on that conditional.
Proposal: The pipeline conditional component is XPath expression over
document. If you need more, build a document and use that?
Accepted.
What about XPath 1 vs. XPath 2?
Murray: We could put the statement in terms of the available processor.
Norm suggests that won't work
Henry: Several possibilities:
... 1. Use a convention for naming XPath expressions that are the values
of attributes; xpath=, xpath1=, or xpath2=
... A question we have to address is, are we going to subset XPath in
order to guarantee that it isn't hard to do this.
... I think we should subset.
Henry proposes that the XPath expressions that you can use in conditionals
to being ones that are streamable
<MoZ> ht, what about attribute minxpathversion="1.0" to parse
Henry: bearing in mind again that if you need the full power of XPath,
then you can use an XSLT processor to build a document ove rwhich a
streaming test will succeed.
Alessandro: We can say that the expression is going to be XPath 1 or 2 and
the engine can analyze the expression and stream if it wants to.
Otherwise, it can just run a full XPath engine
Norm asks if Alessandro is opposed to the subset
Alessandro: Yes
Henry: The problem I have is that it puts a huge burden on the implementor
for functionality that we've already determined most users won't ever use
Norm: My concern is inventing the subset. Do you think the XML Schema
schema subset is appropriate.
Henry: Not quite.
... The thing that's missing is [@foo]
Norm: So the tradeoff is inventing a subset or using an off the shelf
processor. Or is the problem really the analysis for streaming?
Henry: The analysis is hard. Can we float a trial balloon and examine the
possibility of using that in V1?
... Two issues for V.next are, should we accept any XPath or should we
require people to detect a certain class as streamable
Norm: Why detect? Non streaming will always work.
Henry: One of the crucial things about a viewport is that the XPath
expression be streamable because that's how you deal with documents that
are too large to read into memory.
... Conditionals are not the only place where XPath expressions are going
to turn up.
... It seems plausible to try to tell a consistent story.
Norm: I agree, I don't want XPaths on different components to have a
different flavor.
Henry: Maybe the regex for detecting the streaming subset isn't too hard.
Norm ponders the plausibility of using a regex
Henry: I think a regex could detect the the Schema subset
Norm objects to the idea of *requiring* a processor to support streaming
Norm proposes that we take the XPath 1/2/subset question to email
Any other business?
Alessandro: Did we have a conversation about setting up bugzilla
Norm: Yes
-> http://www.w3.org/Bugs/Public/
<Alessandro> Excellent
Norm will make the XPath question an issue as an example
Summary of Action Items
[NEW] ACTION: Norm to begin summarizing the points of consensus [recorded
in http://www.w3.org/2006/04/06-xproc-minutes.html#action02[11]]
[NEW] ACTION: Norm to get this into the CG calendar [recorded in
http://www.w3.org/2006/04/06-xproc-minutes.html#action01[12]]
**
[End of minutes]
----------------------------------------------------------------------
[1] http://www.w3.org/
[2] http://www.w3.org/XML/XProc/2006/04/06-agenda.html
[3] http://www.w3.org/2006/04/06-xproc-irc
[7] http://www.w3.org/2006/04/06-xproc-minutes.html#action01
[9] http://www.w3.org/2006/04/06-xproc-minutes.html#action02
[11] http://www.w3.org/2006/04/06-xproc-minutes.html#action02
[12] http://www.w3.org/2006/04/06-xproc-minutes.html#action01
[13] http://dev.w3.org/cvsweb/~checkout~/2002/scribe/scribedoc.htm
[14] http://dev.w3.org/cvsweb/2002/scribe/
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$Date: 2006/04/07 20:44:34 $
Received on Friday, 7 April 2006 20:49:41 UTC