18:01:39 RRSAgent has joined #xproc 18:01:39 logging to http://www.w3.org/2016/01/27-xproc-irc 18:01:47 rrsagent, set logs world-visible 18:01:47 Meeting: XML Processing Model WG 18:01:47 Date: 27 Jan 2016 18:01:47 Meeting: 297 18:01:48 Chair: Norm 18:01:48 Scribe: Norm 18:01:49 ScribeNick: Norm 18:01:54 Present: Norm, Murray, Alex, Jim 18:01:59 Regrets: Henry 18:03:13 Alex: I don't agree with Henry (from email); I don't want to go back to first principals. We've done all the requirements analysis. 18:03:28 ...I want to build something useful, not recast the requirements yet again. 18:03:33 ...We've done lots of analysis. 18:04:19 Murray: I acknowledge that you've been doing this for a long time. But it's only been a few months since the new ideas came forward as the beginning of a proposal. 18:04:50 ...It feels like things aren't being explained very well. I think we should talk today, even though I said I agree with Henry. 18:05:39 Alex: I feel like we have requirements; they're a guide. We need to go back to them to make sure we do the right thing in the spec. 18:05:54 ... That was always true; this isn't XProc 2.0, this is a proposal for a different direction. 18:06:06 ... There's no consensus that this has any standing at all. 18:06:15 Murray: Let's move beyond the meta-conversation and have the conversation. 18:07:09 Norm: I wanted to talk about the new syntax proposals. 18:07:31 Alex: I think we should talk about the append operator, >> 18:07:45 ... We also need to talk about the upcoming face-to-face. 18:08:14 ... If we're going to polish this as a proposal, we need to make it read like something mortals could understand. 18:09:29 Alex reviews the latest version of the document. 18:09:52 Alex: What Henry identified was that $1 on the left hand side has a different meaning than when it was on the right hands side. 18:10:00 ... We need a way to have a positional output. 18:10:30 ... The farthest right-hand side of things, when there's an output that needs to go someplace, we assign it to a variable.. 18:10:47 ... That's not the same as "send the output of the previous to the output of the next". It's a different thing. 18:10:59 ... I thought we needed a different operator for that. 18:11:06 ... Jim and I chatted about it and came up with ">>". 18:11:53 ... There happens to be a single Unicode character fo rit. 18:12:00 s/fo r/for / 18:12:14 ... So now there's nothing to do with output in the first section. 18:12:49 Alex: I did add square brackets in the 'Step Chains' section. 18:13:00 ... It's an ordered list of sorts, it's an array kind of thing. 18:14:33 Alex reviews Appending Chains and Outputs 18:14:41 Alex: The identity becomes $in >> $out. 18:14:50 ... We can use >> "filename.xml" for storing to that URI> 18:15:00 s/URI>/URI./ 18:15:16 Murray: Are you appending to that file, or replacing it? 18:15:24 Alex: Appending if it exists. 18:15:32 ... If you do it more than once, we have to define what it means. 18:16:30 ... We have to define the semantics for what "append to a URI means" 18:16:37 s/URI means"/URI" means/ 18:17:00 Murray: It's really confusing if you say this is what it means and then say that you have to define what it means. 18:24:00 Some discussion of the order of outputs in >> $included. Order is implementation determined. 18:33:45 Some discussion of the use of $1 in XPath expressions 18:34:06 Alex: You're going to have to do static analysis on the expressions. There just isn't going to be any way around that. 18:36:47 Jim: Do we have a default context within the curly braces? 18:37:01 Jim: Could it be the "." instead of $1? 18:37:09 Alex: We're going to have to define the context. 18:38:04 ... In a block expression, you're going to have to have a way of talking about positional inputs and ouputs. 18:38:17 Murray: I understand about positional inputs. There's more than one stream coming into this process. 18:38:40 ... Or more than one command line argument. 18:39:31 Norm attempts to explain xslt() -> { $1, $2 } 18:39:53 Murray: When I see a '$', I think of a variable. But we're using them to be a variable representation of a port. 18:40:00 ... When I suggested @, I was suggesting @ instead of $. 18:40:20 ... If you're going to create a reference to a port then any subsequent uses of that port would use @. 18:40:33 ... So you'd write to @out, >> @out, and then later you'd refer to @out. 18:41:20 Alex: We could have a different syntax for port references. That would be more consistent with @1, @2, etc. 18:41:28 ... We have scoping questions that go along with that. 18:41:42 ... You have scoping rules for port references and for variable references. 18:42:16 ... My want had been to make the rules on the input side be the same. We should be able to use the output port assigned to some variable as a variable reference. 18:42:36 ... There's an immediate correlation between the variable output port and the variable in the expression. 18:42:43 ... I need a way to talk about the input and make an expression against it. 18:43:42 ... If we use a different syntax ,then we don't get that for free. We have to have some way to convert a port name into a sequence of things. 18:44:05 ... Some variables point to ports that have a conversion syntax within XPath. 18:46:07 Murray: I just want to observe that I understood the arguments about using variables. If we have variables and port names, you wouldn't have to use the port names. 18:46:17 ... You could use variables everywhere. But you could write it out "full-hand". 18:46:47 ... Part of the message I'm trying to give here is that I want to see the long version before the contraction. 18:48:57 FWIW I am fine with @ on left hand side .. I think it clearly delineates ports vs options 18:52:11 Topic: Meeting planning 18:52:14 XML Prague 18:52:15 http://www.xmlprague.cz/day1-2016/ 18:52:28 Norm: I propose three half days: half a day to work on the proposal, half a day to prep for the public meeting, half a day for that meeting 18:52:39 ... An introduction, a presentation of the new syntax, and discussion 18:55:06 Jim: I think we need an answer for XML syntax for this language. 18:55:17 ... I don't know what that would be. 18:55:42 ... One question will be: what do we do now that we don't have an XML syntax. 18:57:03 Alex: We only get a few vocal people. 18:58:00 Topic: Any other business? 18:59:17 Jim: For the f2f meeting, for people who aren't attending, is there going to be any attempt to have telepresence? 19:00:39 Adjourned