XProc Minutes 28 June 2007

See http://www.w3.org/XML/XProc/2007/06/28-minutes

W3C[1]

                                   - DRAFT -

                            XML Processing Model WG

Meeting 73, 28 Jun 2007

   Agenda[2]

   See also: IRC log[3]

Attendees

   Present
           Norm, Henry, Alessandro, Rui, Paul, Richard, Andrew, Alex

   Regrets
           None

   Chair
           Norm

   Scribe
           Norm

Contents

     * Topics
         1. Accept this agenda?
         2. Accept minutes from the previous meeting?
         3. Next meeting: telcon 5 July 2007
         4. Review of 25 June 2007 Editor's Draft
         5. Defaulting
         6. Proposal to add "group-by" option to p:wrap
         7. Wrapper name in p:wrap-sequence?
         8. Recursion?
         9. Any other business?
     * Summary of Action Items

     ----------------------------------------------------------------------

  Accept this agenda?

   -> http://www.w3.org/XML/XProc/2007/06/28-agenda

   Norm suggests discussing the defaulting story after review of the editor's
   draft

   Accepted.

  Accept minutes from the previous meeting?

   -> http://www.w3.org/XML/XProc/2007/06/21-minutes

   Accepted.

  Next meeting: telcon 5 July 2007

   Richard give regrets for the next three weeks

  Review of 25 June 2007 Editor's Draft

   -> http://www.w3.org/XML/XProc/docs/langspec.html

   Henry: I had one comment, but it probably comes up on the defaulting
   thread.
   ... In section 2, it says "each step declares its input and output ports"
   ... that's not true, they have bindings, but not declarations.
   ... editorially, I think it might be good to distinguish between steps and
   types of steps somewhere around here.

   Norm: It sounds like it might be a little premature to publish this draft.

   Henry: Assuming that whatever we decide about defaulting is judged by the
   editor to be straightforward, I'd be prepared to do a New Orleans vote for
   next week.

   Norm: Yeah, maybe that's the way to go.
   ... So can we assume that we'll publish this draft, plus any defaulting
   story, next Friday if there are no objections.

   No objections.

   Paul: When's last call?

   Some discussion of scheduling; Henry, Richard out for July

   Henry: I'm happy to go to last call before I return.

   Norm: Let's aim to have the last call go/no go vote on 26 July

   Henry: I suggest a New Orlean's vote on the 26th too

   More discussion

   Last call before Extreme, CR in August, PR in September, if we have enough
   impls.

  Defaulting

   -> http://lists.w3.org/Archives/Public/public-xml-processing-model-wg/2007Jun/0171.html

   Richard reviews the proposal

   Richard: Only default inputs and outputs get connected up automatically.
   ... A disadvantage of defaulting in general is that it allows you to make
   mistakes.

   Norm: How do folks feel about that?

   Accepted.

   Norm: A pipeline with no declared inputs gets a default one if the first
   step needs one.

   Richard: Right. If you want a pipeline with no inputs, make sure the first
   step doesn't have an unbound default input.
   ... We do a similar thing for outputs.
   ... Unconnected default output on the last step becomes the pipeline
   output.
   ... We also propose that other default outputs not be left unconnected.
   ... The store component, for example, would be declared not to have a
   default output.
   ... So you'd have to connect that up exlicitly.

   Henry: Inputs and outputs and defaulting are now completely symmetrical.
   ... A single input/output is the default, otherwise you have to specify.

   Richard: I think this natural. The thing you think of as flowing through
   the pipeline will usually flow throw the default inputs and outputs.

   <Zakim> ht, you wanted to request an independent decision about what, if
   it's allowed, is meant by "<p:input port="..."/>

   Norm: Does anyone object to the proposal so far?

   Accepted.

   Henry: The first separable question is, should we continue to allow inputs
   with no bindings, and what should it mean?
   ... I think there are two choices: given that if you want an empty
   sequence, you write <p:empty>.
   ... First is, it's an error. You must give an input content.
   ... Alternatively, it means give me the default readable port.
   ... I marginally prefer the latter.

   Richard: It let's you bind to the preceding step without using its name.

   Henry: Ok.

   Norm: I'm ok with this and I think it should bind to the default readable
   port.
   ... Anyone object to connecting a named, but unbound, input port to the
   default readable port?

   Accepted.

   <Zakim> ht, you wanted to suggest treating all containers alike wrt
   missing outputs

   <ht> <p:pipeline><p:xinclude/></p:pipeline>

   Henry: It seems like what we've said about pipelines ought to also work
   for other compound steps.

   <ht> <p:choose><p:when
   test="..."><p:xinclude/></p:when><p:otherwise><p:identity/></p:pipeline>

   Norm: I'm worried a little bit about the complexity of our story, but I do
   agree.

   Henry: So I propose that we allow compound steps to get a default output.

   Some discussion.

   Henry: The names and cardinalities should remain the same, this is only
   for the case where none of the branches declare any outputs.

   Norm: If any branch declares an output then they all have to declare them
   the same.

   Henry: The spec should say that they all have to be the same.

   Richard: What about the case where choose has multiple outputs because all
   of the branches have multiple outputs.

   Henry: They must all be the same.

   Norm: Any objections to this proposal?

   Accepted.

   <Zakim> Norm, you wanted to reintroduce p:sink

   Norm: Can we p:sink, please?

   Henry: Yes.
   ... Although it is the case that p:store could be used for this purpose if
   we invented a /dev/null URI, but it would be harder to optimize.

   Richard: We now have possibility of pipelines themselves with unnamed
   inputs and outputs. It will be a question for implementations how they
   connect these up?

   Norm: Anyone object to p:sink?

   Accepted.

  Proposal to add "group-by" option to p:wrap

   ->
   http://lists.w3.org/Archives/Public/public-xml-processing-model-wg/2007May/0377.html

   Henry: I made a proposal, I stand by it.
   ... I know that Mohamed wants a subsidary XPath that identifies what you
   can ignore.
   ... I think that's the wrong end of the 80/20.

   Norm: We can add that later, if we're convinced.
   ... Any objections to Henry's proposal?

   Accepted.

  Wrapper name in p:wrap-sequence?

   ->
   http://lists.w3.org/Archives/Public/public-xml-processing-model-wg/2007Jun/0190.html

   Norm: We ought to make the wrapper a QName.

   Alex: Yes.

   Norm: Any objections?

   Accepted.

  Recursion?

   ->
   http://lists.w3.org/Archives/Public/public-xml-processing-model-wg/2007Jun/0198.html

   Norm outlines the state of play as he understands it.

   Norm: I think we should make it explicitly allowed.
   ... Any objections?

   Accepted.

  Any other business?

   None.

   Adjourned

Summary of Action Items

   [End of minutes]

     ----------------------------------------------------------------------

   [1] http://www.w3.org/
   [2] http://www.w3.org/XML/XProc/2007/06/28-agenda.html
   [3] http://www.w3.org/2007/06/28-xproc-irc
   [11] http://dev.w3.org/cvsweb/~checkout~/2002/scribe/scribedoc.htm
   [12] http://dev.w3.org/cvsweb/2002/scribe/

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    $Date: 2007/06/28 18:10:35 $