14:43:07 RRSAgent has joined #xproc 14:43:07 logging to http://www.w3.org/2006/09/07-xproc-irc 14:43:32 Meeting: XML Processing Model WG 14:43:33 Scribe: Norm 14:43:33 ScribeNick: Norm 14:43:33 Date: 7 Sep 2006 14:43:33 Chair: Norm 14:43:34 Agenda: http://www.w3.org/XML/XProc/2006/09/07-agenda.html 14:43:36 Meeting: 34 14:55:21 PGrosso has joined #xproc 14:59:25 XML_PMWG()11:00AM has now started 14:59:33 +Norm 14:59:41 +[ArborText] 14:59:45 +Murray_Maloney 15:00:08 ht has joined #xproc 15:01:29 MoZ has joined #xproc 15:01:53 zakim, who's on the phone? 15:01:53 On the phone I see Norm, PGrosso, Murray_Maloney 15:02:06 +??P17 15:02:15 zakim, ??P17 is MoZ 15:02:15 +MoZ; got it 15:03:29 zakim, please call ht-781 15:03:29 ok, ht; the call is being made 15:03:30 +Ht 15:03:39 +Alex_Milowski 15:04:01 alexmilowski has joined #xproc 15:04:10 zakim, who's on the phone? 15:04:10 On the phone I see Norm, PGrosso, Murray_Maloney, MoZ, Ht, Alex_Milowski 15:04:14 richard has joined #xproc 15:04:16 zakim, please call Michael-Office 15:04:16 ok, MSM; the call is being made 15:04:18 +Michael 15:04:41 +??P26 15:04:42 zakim, ? is richard 15:04:43 +richard; got it 15:05:06 zakim, who's on the phone? 15:05:06 On the phone I see Norm, PGrosso, Murray_Maloney, MoZ, Ht, Alex_Milowski, Michael, richard 15:05:18 Present: Norm, Paul, Murray, Mohamed, Henry, Alex, Richard, Michael 15:05:24 Regrets: Alessandro, Erik 15:05:31 Topic: Accept this agenda? 15:05:31 -> http://www.w3.org/XML/XProc/2006/09/07-agenda.html 15:05:54 Accepted. 15:05:57 Topic: Accept minutes from the previous meeting? 15:05:57 -> http://www.w3.org/XML/XProc/2006/08/31-minutes.html 15:06:02 Accepted. 15:06:06 Topic: Next meeting: telcon 14 Sep 2006 15:06:18 No regrets given 15:06:24 Topic: Review of open action items 15:06:47 A-13-01: Continued. 15:07:02 AndrewF has joined #xproc 15:07:04 Topic: Liason with GRDDL WG? 15:07:31 s/Liason/Liaison/ 15:07:38 +??P0 15:07:39 zakim, ? is AndrewF 15:07:39 +AndrewF; got it 15:07:56 Tag, you're it, Murray. 15:08:11 ACTION: Norm to send mail to the GRDDL WG chair 15:08:20 Topic: Technical discussion 15:09:05 Step Container Proposal: -> http://lists.w3.org/Archives/Public/public-xml-processing-model-wg/2006Sep/0003.html 15:10:01 Alex: First, I'd like to introduce the concept of a Component Type 15:11:57 ...Viewport and other language constructs create their own component type. 15:12:43 Henry: I agree with the idea. Viewports and things like them need declare-outputs. 15:13:00 ...Are there any substantive differences from the UML I sent out last week? 15:13:18 q+ to ask whether 'component type' as described in 1 has anything to do with what actually happens to the data - or is it just a signature? 15:14:30 Some discussion of how Alex's proposal and HT's diagram differ 15:14:56 Richard: Is there a distinction between the signature and the type? 15:15:35 MSM: If I have two components with the same inputs and outputs, are they the same type or different? 15:15:46 Alex: I think they'd be different because they'd have different names. 15:16:03 MSM: I'm perfectly happy to say that the name is part of the component type. 15:16:20 Richard: Type and signature seem to cover the two cases here. 15:16:58 HT: In my diagram, the signature includes the kind so they're the same. 15:17:20 MSM: I like the word signature without the kind. 15:17:54 HT: I don't see any need for a signature without the kind, but I'm happy to change the name on the diagram 15:18:18 Richard: We can introduce it as a term that may be useful without having an impact on the semantics. 15:18:25 ...The connections to a component must match its signature. 15:18:33 s/The/We could say that the/ 15:18:53 One point worth considering: it's useful to define terms if they will be useful to people discussing the spec, whether they have work to do in normative spec prose or not. 15:18:58 q+ to point out that the spec currently uses the word "signature" 15:19:01 ack MSM 15:19:01 MSM, you wanted to ask whether 'component type' as described in 1 has anything to do with what actually happens to the data - or is it just a signature? 15:19:27 Richard: Alex, you're proposing that we create subtypes that only have one instance. 15:19:31 Alex: yes. 15:19:51 ack Norm 15:19:51 Norm, you wanted to point out that the spec currently uses the word "signature" 15:20:30 Norm: We already use the word "signature" in the spec. 15:20:38 Alex: I'm happy to say that the component type is a signature with a name. 15:21:29 Alex: I wanted to have a name for these things like viewport, and for-each, etc. that contain steps. 15:21:38 I called them "step containers" 15:21:47 s/I called/Alex: I called/ 15:22:10 I suggest "container step" rather than "step container", to emphasize that it's a step 15:22:46 Norm: I was resistant, because I don't want to make them too special, but it will help in the exposition of where bindings can occur. 15:23:31 Norm: I sort of like "container step" better 15:23:46 Richard: It's only one of the aspects of the steps that they're containers. They have other specialnesses to them. 15:24:08 ...In particular, they provide control flow. 15:24:23 Murray: Can I suggest the word "procedure" as a grouping of steps. 15:24:43 MSM: There's lots of baggage connected with that term. 15:25:34 Alex: Maybe we need more terms, but having a term for just the container nature seems useful. 15:26:05 Richard: I agree. It may not be immediately apparent that there's an analogy between these control structures and pipelines themselves. 15:26:10 [Would 'compound step' be a useful term?] 15:26:30 [by analogy with 'compound statement' in other pgoramming langauges] 15:27:19 q+ Murray 15:28:31 HT: Pipelines are not in the category of things that a graph is made of. I'd rather not give this a name thta's associated with stage. 15:28:52 Alex: But a pipeline library is for pipelines that you use as steps 15:29:33 HT: I thought we said that there may be a component that allows you to call a component by name, but you can't put a p:pipeline inside a choice. 15:30:46 HT: There are common or garden steps and language constructs which assemble into the graph. 15:31:00 ...We distinguished from that pipelines that are packaging for graphs for unitary invocation. 15:31:08 ...I thought on that basis that pipeline was special. 15:31:17 so is there a name for what you write when you invoke a pipeline as a step? 15:31:32 Yes, MSM, p:step name="pipelineName" 15:31:40 s/name=/component=/ 15:31:54 HT: We need a category for the things you can join up with inputs and outputs. Pipeline is not in that category. 15:33:00 q+ 15:33:20 Alex: Pipelines are pretty much exactly like group. One way out of this box is to say that a pipeline is an extension of a group. 15:33:31 ...When you use it in a step you're invoking that group. 15:33:41 HT: But it may be named, may contain component declarations, etc. 15:34:05 [It seems we are talking about two sets: the set of things that contain steps, and the set of things that can go inside a choice or other container. Set 1 seems to be equal to Set 2 + {p:pipeline}. 15:34:48 ack Murray 15:35:12 Murray: Rather than simply saying that it has a lot of baggage, can someone explain why "procedure" is not a good choice? 15:35:55 Richard: I find it anti-intuitive. In other programming languages, procedures are the things that aren't syntactic constructs. 15:36:14 [My concern with the term "procedure" is that it suggests to me very strongly an association with parameters and arguments, which I think doesn't match up very well with these constructs.] 15:36:19 ...In C or Algol, or any of those things, a procedure is something you call, it's not a control structure. "If" is not a procedure in any language like that. 15:36:39 Murray: But in everyday language, it is fine. 15:36:57 Richard: Indeed, but in the context of programming languages, it doesn't match very well. 15:37:10 ack Norm 15:37:23 [I think Richard has enunciated another aspect of my concerns, too.] 15:37:31 Murray: We seem to have trouble sticking with the metaphore of pipelines that we've adopted. 15:37:47 Murray: In wikipedia, the description of a pipeline includes "processes" 15:38:25 ...I keep tripping on various english language constructs where there seem to be simpler english words. 15:39:03 I think 'procedure' would be a good alternative for what we have called 'group' heretofore 15:39:21 MSM: I think that there are two different sets we're talking about. 15:39:23 but not for the category including group-as-was and choose and for-each 15:39:35 ...One is the set of constructs that can contain other constructs, of which the pipeline element is clearly a member 15:39:54 ...And the other is non-atomic constructs that can occur as constructs, of which pipeline is not a member. 15:40:25 HT: They both need names. One needs input/output decls everytime they're used and the other is something that can be connected together. 15:40:38 HT: Stages is the word in the diagram for things that you can connect with pipes. 15:40:48 HT: It doesn't have a name for the superclass of things that have things inside them. 15:41:27 Richard: I find Alex's description quite compelling. We need a name for things which contain steps and need declarations. 15:41:48 ...Then we can say that so-and-so is a step container and you know how it's connected up. 15:42:13 [The need for the latter is: what can go into a 'when' ? ] 15:42:23 Richard: In HT's diagram, stage is that plus ordinary steps. 15:43:30 Alex: I want to observe that pipelines are a lot like a group. 15:44:42 Group is a local scope for a set of parameters. 15:44:46 s/Group/Murray: Group/ 15:46:07 Norm: Is one of these names the least controversial? 15:46:21 Step container 15:46:26 Container step 15:46:31 Procedure 15:46:34 Compound step 15:47:53 Step container looks to be a minimally controversial choice 15:48:03 Murray objects but encourages us to proceed anyway 15:48:16 We'll go with "step container" provisionally. 15:48:54 HT: This is the first time where I'm moved to do double inheritence in the diagram 15:49:03 Norm: Where? 15:49:12 HT: Pipeline and construct are both going to be subclasses of step-container 15:49:23 ...And step container will have a body that is a flow graph 15:49:30 ...Which is fine, that is actually accurate. 15:50:59 Norm: I think the rest of Alex's message describes the constraints on input/output bindings in terms of what we've just discussed. 15:51:05 Alex: Yes. We don't say enough about this yet. 15:51:20 Alex: This is the point that we had heartburn about at the f2f. 15:52:14 Richard: Step containers bind their input ports to other steps. Right. 15:52:55 Alex: The input binding can't be to something inside you. 15:53:05 Alex: You could bind to the input of some ancestor. 15:53:55 Alex: It might be nice if we could get away from this input/output problem. 15:54:17 Richard: We bind inputs ot sources and sources can either be outputs of siblings or declare-inputs of ancestors. 15:54:21 s/ot /to / 15:54:50 Topic: Any other business 15:55:17 Alex: I sent out a standard library definition. I think it would be good to start writing definitions of the standard components. 15:56:05 Alex: I could start with the use cases and put it together in a more formal way. 15:56:16 Norm: Go, man, go! 15:56:21 Murray: I've come up with another term. 15:56:27 Murray: How about a work flow? 15:57:10 Norm expresses reservations because we're not doing choreography 15:57:48 Adjourned. 15:57:50 -Murray_Maloney 15:57:51 -richard 15:57:52 -PGrosso 15:57:53 -Norm 15:57:53 -MoZ 15:57:54 -Alex_Milowski 15:57:54 -AndrewF 15:58:01 -Michael 15:58:03 PGrosso has left #xproc 15:58:06 rrsagent, set logs world visible 15:58:06 I'm logging. I don't understand 'set logs world visible', Norm. Try /msg RRSAgent help 15:58:17 rrsagent, draft minutes 15:58:17 I have made the request to generate http://www.w3.org/2006/09/07-xproc-minutes.html Norm 15:58:36 ht, maybe you and I can chat for five minutes after you've published the next diagram 15:58:56 I'm sure there's an "aha!" moment in UML for me somewhere :-) 15:59:09 Sure 15:59:33 rrsagent, set logs world-visible 15:59:37 I propose writing the semantics in French so that we get a whole new set of words 15:59:50 richard++ 15:59:59 We could use private use characters from unicode. 16:00:06 Then we could choose our own glyphs too! 16:00:07 (except of course in the French translation of the spec, in which they would be in German) 16:00:09 Private use? 16:00:19 Surely there are Unicode characters for "flow" and "graph" and such? 16:00:32 And then we'd have an unpronounceable name. 16:00:32 There's all those VT100 graphic symbols 16:00:45 yes, but private use is much more fun - if you don't use the PUA, how will we ever manage to get into a catfight with I18n? 16:00:47 Kinda like Prince. 16:01:19 We already grabbed the private use characters starting #xED for EDinburgh use 16:05:00 disconnecting the lone participant, Ht, in XML_PMWG()11:00AM 16:05:03 XML_PMWG()11:00AM has ended 16:05:04 Attendees were Norm, Murray_Maloney, PGrosso, MoZ, Ht, Alex_Milowski, Michael, richard, AndrewF 16:05:19 alexmilowski has left #xproc 17:22:55 Norm has joined #xproc 18:01:36 Zakim has left #xproc 19:33:49 Norm has joined #xproc 21:27:36 Norm has joined #xproc