- From: Norman Walsh <ndw@nwalsh.com>
- Date: Thu, 30 Aug 2007 12:25:52 -0400
- To: public-xml-processing-model-wg@w3.org
- Message-ID: <m2hcmhat0v.fsf@nwalsh.com>
See http://www.w3.org/XML/XProc/2007/08/30-minutes
W3C[1]
- DRAFT -
XML Processing Model WG
Meeting 81, 30 Aug 2007
Agenda[2]
See also: IRC log[3]
Attendees
Present
Norm, Paul, Rui, Mohamed, Andrew, Henry, Richard
Regrets
Chair
Norm
Scribe
Norm
Contents
* Topics
1. Accept this agenda?
2. Accept minutes from the previous meeting?
3. Next meeting: telcon 6 September 2007
4. Charter extension :-(
5. Meeting at the W3C Technical Plenary
6. Comments on the new draft
7. p:pack
8. Type attribute on p:option, etc.
9. Namespace fixup
10. Error numbers
11. Any other business?
* Summary of Action Items
----------------------------------------------------------------------
Accept this agenda?
-> http://www.w3.org/XML/XProc/2007/08/30-agenda
Add: splitting the spec?
Accepted.
Accept minutes from the previous meeting?
-> http://www.w3.org/XML/XProc/2007/08/23-minutes
Accepted.
Next meeting: telcon 6 September 2007
No regrets given.
Charter extension :-(
Norm: Henry, what do we need to do?
Henry: I'm not sure, but as a tactical matter let's wait until we get to
Last Call before we do it.
Meeting at the W3C Technical Plenary
Norm: We should plan to meet at the plenary, Th/Fr 8/9 Nov 2007 in
Cambridge, MA, US
... I've requested a projector, a whiteboard, and a phone
Norm will be there
Henry will be there in part
Paul will be in the hotel, but at the XSL FO meeting
Comments on the new draft
-> http://www.w3.org/XML/XProc/docs/langspec.html
Henry: Woo hoo! seems appropriate
Norm: Did anyone look at Henry's editorial changes
Mohamed: I did and I think it addressed many issues.
... I think some of the type stuff isn't in the spec (options that must be
QNames, etc.)
Henry: I think that stuff is in 3.9
Mohamed: Yes, that's ok. But I think some of it is missing in required
steps.
Henry: At the moment, the changes in section 7 are only visible in the
copy attached to the email that I sent
Mohamed: Ok, maybe I was looking in the wrong place.
Henry: I've been trying to make the steps more regular (editorially).
... Alex had evolved towards a standard way, but they hadn't all been
updated
Norm regrets Alex's absence.
Henry summarizes his editorial changes.
Norm: I think we should accepted Henry's changes.
Norm and Henry will work together on the draft.
Mohamed: I'm very happy with the styling changes in the tableaus
Norm: Yeah, I think it worked out pretty well too, though I'm open to
suggestions for more improvements.
p:pack
http://lists.w3.org/Archives/Public/public-xml-processing-model-wg/2007Aug/0080.html[7]
http://lists.w3.org/Archives/Public/public-xml-processing-model-wg/2007Aug/0101.html[8]
Mohamed: We're only missing a few things, most of which we can get with
options.
... An option on p:count would allow it to return 0, 1, or more instead of
counting all of them
... Adding an option on split-sequence to stop after first false, that
could be an option too.
... And p:pack
... I'm not sure I want all of them, but I was trying to see what we
couldn't do.
... Some of them would require p:input="*" and p:output="*".
... But the three named above could be done pretty easily.
Norm: I'm sort of inclined leave these until the next release or as exproc
extensions.
... What do folks think of a 0, 1, or more sort of step as an
alternative/option to p:count?
Henry: I'm not sure how central the requirement for this is?
... I appreciate that there's an in principle need, but what is the
real-world use case?
Norm: I'm not hearing a lot of support
No consensus to add this.
Norm: What about a variation on p:split-sequence to stop after the first
false?
Henry: Same question
Norm: I'm not hearing a lot of support for this either
No consensus to add this.
Henry: I think it will be very reasonable during CR to respond to requests
of the form "please add a step such as..." with some optional step that we
might eventually make required.
Norm: That leaves us with p:pack
Mohamed: The use case for this one is to make a comparison of two
sequences of documents.
Norm: I see, so instead of having two sequences, you can just take the
first two and then the next two, etc.
Mohamed: You get the two documents in a single wrapper
<MoZ> <A><a/><b/></A>
Norm: Right.
Henry: I'm still not clear; if I have four documents on each input port,
how many do I get?
Mohamed: You get four output documents; each of which contains a wrapper
that has two documents.
Henry: I think this probably is a good idea.
... It's the dual of split-sequence to some extent and it matches a unix
utility that I use occasionally
Norm: Anyone object to adding p:pack?
None heard; accepted.
Type attribute on p:option, etc.
Norm: There's been some discussion in email.
Proposal: Add a type attribute on p:option?
No support heard, at least one object; proposal fails.
Namespace fixup
Scribe interrupted by FedEx
Henry: At the beginning of 2.2, we say that it's XML that flows between
steps.
... There is no statement here which says that the XML must be
serializable as an XML document.
Richard: I don't think that's what we should be saying.
Henry: As it stands, as an implementor, I don't think I'd have any
obligation to throw an error if a step produced as output an
unserializable document information item.
... e.g., I am XML 1.0 based implementation and you give me a document
which has two elements with an undeclared namespace.
<root xmlns="foo"><child xmlns=""/></root>
You can't do that in XML 1.0
(That example doesn't actually work, but hopefully the idea is clear)
Henry: The problem arose in p:add-attribute. Do we require namespace
fixup? That is, should we say that the output document contains an
in-scope namespace binding for the prefix used in the attribute if there
isn't one already.
Richard: It seems that on the individual questions of what steps should
do, we should say.
Henry: I think that's a question we should put to the WG.
<MoZ> <p:root xmlns:p="foo"><p:child xmlns:p=""/></p:root> is impossible
in XML 1.0 but we just have to change the prefix !
Richard: As to the general question, we say that the things that flow
between the steps are XML documents. So if you attempt to pass an
unserializeable infoset, that's clearly an error.
... I think this should be partitioned between a general statement like
that statements about the individual steps.
Henry: I think there's a finer granularity that's worth considering.
... There are at least two senses of serializable:
... Given a fairly close transcription of the infoset, one possible
reading of "serializable" is, if you express every property in your object
model, the result will be a WF XML document.
... The next step is to say, no, that's too weak, the sensible meaning is
that with the addition of namespace bindings and possibly additional
prefixes, the document could be serialized successfully.
Richard: I'd say that the definition is that there's a textual XML
document that has the same infoset.
... If we wished to allow some latitude on that then the components
themselves should say what the latitude is.
Henry: I think that means: in one case the spec says, if serialization is
called for then it must be possible with namespace bindings synthesized as
necessary.
... The other alternative is to say that that must obtain at every
transition between steps.
Richard: I would be happy to allow implementations the latitude of not
fixing up namespaces until they actually serialized the output.
... But that should be considered an optimization
... Each step should say that it works as if such a document was possible
at every transition
Henry: So this means describing namespace fixup for at least all ten of
these steps
... I'm happy to do that, but it seems overkill.
Richard: I'd abstract the problem and write a single paragraph that says
that.
Norm: Anyone disagree with the strict reading of serialization between
steps?
Henry: Yes, I think this is an unbearable burden on implementors.
Richard: Where do errors occur if you don't?
Henry: Given that we have an XSLT 1.0 step, it's clear that this can be
done.
... All you have to do is do add attribute and then check the namespace
bindings with XSLT.
... It's definitely detectable.
Richard: I'm not against it being an allowed optimization to do this, the
thing that I want is that the spec be written as if every step produced
and consumed textual XML and anything else is an optimization.
Some discussion about what 2.2 meant.
Henry: I'm happy to reword this paragraph but I think we need to do it
with our eyes open.
Mohamed: I object to the idea that we put this burden on implementors too.
Norm: Let's take this to email
Richard: I think the minimum position is that steps be allowed to
serialize between every step and be allowed to produce an error if they
can't.
Error numbers
No value in fiddling with the error numbers and non-zero chance of screw
up.
Any other business?
None.
Adjourned.
Summary of Action Items
[End of minutes]
----------------------------------------------------------------------
[1] http://www.w3.org/
[2] http://www.w3.org/XML/XProc/2007/08/30-agenda
[3] http://www.w3.org/2007/08/30-xproc-irc
[7] http://lists.w3.org/Archives/Public/public-xml-processing-model-wg/2007Aug/0080.html
[8] http://lists.w3.org/Archives/Public/public-xml-processing-model-wg/2007Aug/0101.html
[9] http://dev.w3.org/cvsweb/~checkout~/2002/scribe/scribedoc.htm
[10] http://dev.w3.org/cvsweb/2002/scribe/
Minutes formatted by David Booth's scribe.perl[9] version 1.128 (CVS
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$Date: 2007/08/30 16:18:24 $
Received on Thursday, 30 August 2007 16:26:07 UTC