W3C

- DRAFT -

XML Processing Model WG

Meeting 230, 24 Apr 2013

Agenda

See also: IRC log

Attendees

Present
Norm, Henry, Jim, Alex
Regrets
Chair
Norm
Scribe
Norm

Contents


Accept this agenda?

-> http://www.w3.org/XML/XProc/2013/04/24-agenda

Accepted.

Accept minutes from the previous meeting?

-> http://www.w3.org/XML/XProc/2013/03/20-minutes

Accepted.

Next meeting: 1 May 2013

Henry gives regrets for 1 May.

Review of open action items

Henry's items are on the agenda; no other progress reported.

Proposed changes to schemas/libraries

<ht> http://lists.w3.org/Archives/Public/public-xml-processing-model-wg/2013Mar/0028.html

Henry: It's a long message, but basically, I propose to adopt the defacto model for non-REC but REC-related resources.
... Follow the approach of the RECs themselves, but a little less formally. There's a URI that will be point to a mutable resource and another, dated, URI, that will never change.
... We should update the spec to point to both the dated and undated URIs.

Norm: Attempting to recall why we don't point to the pipeline library. At one time, you could import it if you wanted to; we had some weird rules about what to do with steps that werent' recognized, etc.
... We changed the rules at some point so that you can't import it and when we did that we removed the link; but I think we should put it back.
... It's still used in the construction of the spec itself.

Jim: I think we should put the link back.

Norm: I think we should do what Henry suggests.
... I think Henry can make the dated and undated URIs and I can propose the spec errata.

Henry: Yes, I think that makes sense.

Norm: Any objections to this course of action?

Accepted.

A-215-02: Closed

A-215-04: Closed

<scribe> ACTION: A-230-01: Henry to create dated and undated versions of the schemas and pipeline library in appropriate locations [recorded in http://www.w3.org/XML/XProc/2013/04/24-minutes#action01]

<scribe> ACTION: A-230-02: Norm to propose errata along the lines described in msg 2013Mar/0028 [recorded in http://www.w3.org/XML/XProc/2013/04/24-minutes#action02]

Use cases and requirements?

Jim: No progress. I'm trying to get zip/unzip done.

Zip and unzip steps?

Jim: No progress there either.

Bug 21003, errors in 4.4.1, p:xpath-context

-> https://www.w3.org/Bugs/Public/show_bug.cgi?id=21003

Norm: If the p:xpath-context is omitted, then the default readable port is used, I believe. If it doesn't say that, we should make an erratum to do so.

Henry: Yes, but what about Vojtech's comment?

Norm: I think what I said still applies; the default readable port is used if there's no p:xpath-context and it's explicitly not an error if there's no default readable port. The context is simply undefined.

<ht> Agreed

Norm: (with the standard XPath 1.0 hand wave at what undefined means)

<scribe> ACTION: A-230-03: Norm to propose the erratum to resolve bug 21003 [recorded in http://www.w3.org/XML/XProc/2013/04/24-minutes#action03]

Bug 21004, errors in 5.7.1, p:variable

-> https://www.w3.org/Bugs/Public/show_bug.cgi?id=21004

Jim: This appears to just be an editorial error.

Norm: I bet it's a cut-and-paste error by the editor.
... I think the solution is simply to remove the apparently conditionality of the select expression.

Norm:Something like: s/If a select expression is given, it is/The select expression is/

<scribe> ACTION: A-230-04: Norm to propose the erratum to resolve bug 21004 [recorded in http://www.w3.org/XML/XProc/2013/04/24-minutes#action04]

Bug 21005, specification error wrt in-scope bindings

-> https://www.w3.org/Bugs/Public/show_bug.cgi?id=21005

Henry: It happens in 2.6.1.1.
... The note in 'variable bindings' should be amended to be more precise. There's no straightforward referent for the phrase 'that variable' in the note.

<scribe> ACTION: A-230-05: Henry to propose an erratum that fixes the phrase 'that variable' in the note in 'variable bindings' in 2.6.1.1 [recorded in http://www.w3.org/XML/XProc/2013/04/24-minutes#action05]

<ht> "An option that has neither a specified value nor a default value will not appear as an in-scope variable. Consequently, an attempt to refer to that variable will raise an error." should change to "An option that has neither a specified value nor a default value will not appear as an in-scope XPath variable. Consequently, an attempt to refer to an XPath variable whose name is the name of such

<ht> an option will raise an error.

Norm: Looks good to me.

<scribe> ACTION: A-230-05: Norm to put Henry's erratum text in the errata document [recorded in http://www.w3.org/XML/XProc/2013/04/24-minutes#action06]

Henry: There's still a a problem because I don't think 'in-scope specified options' is well defined.
... No, I take that back. I think we can just use the phrase 'specified options' in clause 5 or perhaps in a new clause 6. Yes, a new clause 6 probably.

Norm: What happens if you say p:namespaces binding=fred and fred is an optional option with no value; is that just a gaping whole in the spec?

Henry: Seems likely.
... But I think the proposed cure is way more expense than is necessary.
... I think it's true if it's a static error if the namespace binding isn't there, but it's also a dynamic error if something you thought was going to be there turns out not to be.

Norm: Yes, I agree that special casing that one issue seems better.

Henry: The reason it's not statically known is that you might have a declared step with a declared option with no default which is invoked in two different places in the pipeline and in one of those places the value is supplied and in the other it isn't. So without complete NP-complete flow analysis, you can't tell whether it's going to be called with or without the option.
... You could imagine we make a rule that says that static analysis has to make the worst case assumption....but that seems unreasonable.

Norm: I'd like to do an experiment or two.

<scribe> ACTION: A-230-07: Norm to setup a test case for the optional option/p:namespaces binding and see what implementations do. [recorded in http://www.w3.org/XML/XProc/2013/04/24-minutes#action07]

<jf_2013> +1

Norm: We'll see what happens in the wild and then come back to this one.

Bug 21006, errors in 4.4, p:choose

-> https://www.w3.org/Bugs/Public/show_bug.cgi?id=21006

Jim: Why aren't p:when and p:otherwise steps?

Norm: Uhhh...because they don't inherit from their preceding siblings etc.

<ht> because they can't appear outside of p:choose

<ht> Right, "substitutions for the body" -- think of it that way

Henry: I'd be tempted to actually think about re-casting the whole section or at least adding a note that says something along those lines. i.e., processors should behave as if the p:choose was the p:choose was replaced by a step consisting of the chosen branch.

Norm: It's ugly; there's static and dynamic behavior.

Henry: Yes, but that's about picking which one is chosen. The fact that you don't know until runtime which one is going to be chosen, but you have to know the static features of the step, you get a whole bunch of constraints that follow naturally.

Norm: Henry, would you be willing to review the section and see how much violence you think would be inflicted if we attempted to recast it along the "substitutions for the body" idea?

<ht> yes, happy to give that a go

thanks

<scribe> ACTION: A-230-05: Henry to examine our discussion of p:when etc. and see if it can be easily recast along the lines of 'substitutions for the body' without the confusion about subpipelines. [recorded in http://www.w3.org/XML/XProc/2013/04/24-minutes#action08]

Any other business?

Jim: When might we be able to have another f2f?

I'm going to Balisage and TPAC.

scribe: We could attempt to have a f2f of our own.

<jf_2013> 15-26 July I am on holiday

Norm: There's been some discussion of a meeting in July

<jf_2013> I can do any other time in July

Norm: In Edinburgh. Not specifically XProc, but...

<jf_2013> +!

Henry: If Jim and Vojtech could come to Edinburgh or London...

<jf_2013> London better, but I hvae friends in Edinborough

<ht> Week of the 8th would be good

<scribe> ACTION: A-230-06 Norm to send email about possibly meeting in London/Edinburgh the week of 8 July [recorded in http://www.w3.org/XML/XProc/2013/04/24-minutes#action09]

<ht> Sounds like 10--12 July would suit

Jim: I'm giving a talk on XProc at XML London.

Norm: I'll consider getting to London in mid-June

Adjourned.

Summary of Action Items

[NEW] ACTION: A-230-01: Henry to create dated and undated versions of the schemas and pipeline library in appropriate locations [recorded in http://www.w3.org/XML/XProc/2013/04/24-minutes#action01]
[NEW] ACTION: A-230-02: Norm to propose errata along the lines described in msg 2013Mar/0028 [recorded in http://www.w3.org/XML/XProc/2013/04/24-minutes#action02]
[NEW] ACTION: A-230-03: Norm to propose the erratum to resolve bug 21003 [recorded in http://www.w3.org/XML/XProc/2013/04/24-minutes#action03]
[NEW] ACTION: A-230-04: Norm to propose the erratum to resolve bug 21004 [recorded in http://www.w3.org/XML/XProc/2013/04/24-minutes#action04]
[NEW] ACTION: A-230-05: Henry to propose an erratum that fixes the phrase 'that variable' in the note in 'variable bindings' in 2.6.1.1 [recorded in http://www.w3.org/XML/XProc/2013/04/24-minutes#action05]
[NEW] ACTION: A-230-06: Norm to put Henry's erratum text in the errata document [recorded in http://www.w3.org/XML/XProc/2013/04/24-minutes#action06]
[NEW] ACTION: A-230-07: Norm to setup a test case for the optional option/p:namespaces binding and see what implementations do. [recorded in http://www.w3.org/XML/XProc/2013/04/24-minutes#action07]
[NEW] ACTION: A-230-08: Henry to examine our discussion of p:when etc. and see if it can be easily recast along the lines of 'substitutions for the body' without the confusion about subpipelines. [recorded in http://www.w3.org/XML/XProc/2013/04/24-minutes#action08]
[NEW] ACTION: A-230-09 Norm to send email about possibly meeting in London/Edinburgh the week of 8 July [recorded in http://www.w3.org/XML/XProc/2013/04/24-minutes#action09]
 
[End of minutes]

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$Date: 2013-05-07 14:46:36 $