REBOL3 - XML (xml related conversations [web-public])

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# User Message Date
498 Maxim the change in RebXML was to forego of a few limitiations and to allow direct xpath like useage of the loaded xml... which can't be done with RebXML out of the box. 5-Jun-07 20:31
497 Maxim I did not do it using parse for lack of knowledge ... and also the fact that schema and PARSE do not have the same traversal mechanisms... but its still very fast and error report is extremely precise (it gives you the full path of the error!) 5-Jun-07 20:30
496 Maxim hehe... I have a validating schema parser which uses a modified RebXML engine... but I still have not had the balls to ask my client if we would be willing to make it open source.... I'm sure he would benefit from the extra time people might put on it. 5-Jun-07 20:29
495 Maarten Has anybody done work on translating XML schemas (perhaps automagically) to REBOL parse rules that can work on REbelXML/RebXML like native syntax? 3-Jun-07 20:19
494 Anton I do not know much about the greater issues of XML, however. 18-Jun-06 18:35
493 Anton Well, I just had a quick look. It seems to be clean code, well organised. Perhaps I can find some time to test it out myself in a few days. 18-Jun-06 18:33
492 Christophe Seriously, I need this lib for my work. Is there anybody out there who has ANY comment about it ? Please ... 18-Jun-06 15:31
491 Christophe Well, Ashley, this is very kind of you :-) But after checking the links, it seems Google isn't my friend anymore :-)) 18-Jun-06 15:29
490 Ashley Folks seem to be using/talking about it ... just do a google search on "RebelXML". ;) 18-Jun-06 1:50
489 Christophe Well, no reaction to RebelXML. Do I have to assume it has no bugs or nobody is using it ? :-)) 17-Jun-06 20:07
488 Maxim (I hope my previous post was read as intended... ironically!) ;-) although schema is pretty well defined and actually not too badly designed, its just so huge. 8-Jun-06 17:35
487 Pekr I wonder if REBOL can get standards fully compliant XML parser/emitter .... 8-Jun-06 17:23
486 Maxim implementing schema is sooo much fun! 8-Jun-06 17:21
485 Christophe Is REBOL not pronounce REBEL ? It was just for the fun... 4-Jun-06 6:50
484 Graham why rebel and not rebol? 2-Jun-06 23:33
483 Christophe We'll use it in production very soon. I took a SAX approach because we've to manipulate big XML files, and it was a mean to boost performences. 2-Jun-06 17:10
482 Christophe I submitted RebelXML to rebol.org quite some time from now. I can see it as been examined by some people. Well, it should be great if I could get some feedback about it. 2-Jun-06 17:08
481 Christophe Well, I'm back after a long time off the air... Now back online and talking from a brand new iMac, and I enjoy it :-) 2-Jun-06 17:07
480 Anton Oh, I see, it has optimized the expression. 30-Apr-06 18:25
479 Anton That's pretty cool. But, isn't the output of the rewrite above missing the multiply ? 30-Apr-06 18:24
478 Gabriele do you have common examples that you consider problematic for parse? we can probably use rewrite on the parse rules themselves to extend them in a similar way that compile-rules does. 30-Apr-06 8:54
477 Gabriele (rewrite is currently 25 lines of code) 30-Apr-06 8:53
476 Gabriele >> rewrite [ [ plus [plus [mult [lit 3] [lit 1]] [lit 2]] [lit 0] [ ] [ [ ['lit set x number!] [push (x)] [ ['plus into ['lit 1 1 0] set x block!] [(x)] [ ['plus set x block! into ['lit 1 1 0]] [(x)] [ ['mult into ['lit 1 1 1] set x block!] [(x)] [ ['mult set x block! into ['lit 1 1 1]] [(x)] [ ['plus set x block! set y block!] [(x) (y) add] [ ['mult set x block! set y block!] [(x) (y) mul] [ ] == [push 3 push 2 add ] 30-Apr-06 8:52
475 Gabriele we want to compile it to a forth-like processor 30-Apr-06 8:52
474 Gabriele example: assume the AST for 3*1+2+0 is [plus [plus [mult [lit 3] [lit 1]] [lit 2]] [lit 0]] 30-Apr-06 8:52
473 Gabriele my rewrite function works quite well for search and replace. it still has the limitations of parse, though, but they don't seem a huge problem so far. 30-Apr-06 8:47
472 BrianH Yup. I've posted on rambo about everything I've suggested and more. I hope they consider these suggestions for REBOL 3. 29-Apr-06 22:35
471 Graham Brian, did you post a rambo on parse after a discussion we have a while ago ? 29-Apr-06 22:22
470 BrianH You can do some structural pattern matching with parse rules, but with how parse is currently implemented it can be a little awkward. The lack of arguments to parse rules make recursion quite difficult, and the lack of local variables make the rules difficult to use concurrently. It is difficult to examine both the data type and the value of elements in block parsing, to switch to string parsing mode for string elements, to parse lists, hashes or parens, to direct the parse flow based on semantic criteria (which is needed to work around any of these other problems).
And don't even get me started on the difficulties of structure rebuilding. The thing that is the most difficult to do in parse is the easiest thing to do with regexes: Search and replace. Didn't we make a web site years ago collecting suggestions for improving parse? Wasn't a replace operation one of those suggestions? What happened with that?
Structural pattern matching and rebuilding currently has to be done with a mix of parse and REBOL code that is tricky to write and debug. If parse doesn't get improved, I'd rather use a nice declarative dialect, preferably with before and after structures, and have the dialect processor generate the parse and REBOL code for me. If that dialect is powerful enough to be written in itself then we'll really be cooking.
29-Apr-06 22:00
469 Gabriele brian: do you think that structural pattern matching could be done with parse rules too? or, do you think we need something like "longest match" (which can be implemented in parse but is tedious to do manually) 29-Apr-06 8:30
468 Gabriele (maybe there just isn't any general solution to the problem of selection.) 29-Apr-06 8:28
467 Gabriele so maybe my question is: is graph navigation (or, if you think it is general enough, tree navigation) a general enough selection model, or do you think that it would be missing something? 29-Apr-06 8:28
466 Gabriele when i think about representing data conceptually, i tend to always come up with a graph or a tree (then i map the conceptual graph to a relational model, or maybe to a dialect). so for selecting data a "navigation" approach (which is basically what xpath does) seems rather natural for me; then you can map the navigation to SELECT statements etc if needed. 29-Apr-06 8:26
465 Gabriele i.e., if we think that dialects are better than trees for data. 29-Apr-06 8:20
464 Gabriele selecting dialected data 29-Apr-06 8:19
463 Gregg "can we think of a generic way to select data represented with a dialect?"
Do you mean "selecting dialected data" or "a dialect to select data that's in format X"?
28-Apr-06 20:36
462 BrianH I have often missed structural pattern matching in REBOL, something like the match statement in Nemerle (I'm sure it's in other functional languages but that's the first that came to mind). You could combine a structural pattern specification dialect (like XPath) with a structure building dialect (like XSLT), and then make the dialect compilable to REBOL code that can be used over and over again. It would be like a regex compiler for structures - I would use this every day.
All you would have to do to implement actual XPath syntax would be to specify a standard mapping of XML semantics in REBOL data structures (see my block model in this group from last October) and then have compile the XPath syntax (in a string) to the structure matching dialect. Then you could work from there.
(Gabriele, sorry if this seems redundant - I'm trying to explain tree rewriting in more REBOL-like terms).
28-Apr-06 19:34
461 Gabriele can we think of a generic way to select data represented with a dialect? 28-Apr-06 18:16
460 Gabriele basically, what sql's select is for relational data, xpath is for xml data. 28-Apr-06 18:16
459 Gabriele now, it remains to consider something like xpath for selection 28-Apr-06 17:31
458 Gabriele on top of this, one could probably implement something similar to xslt, to translate a tree (parsed from xml) to another tree (maybe xhtml or another xml doc) 28-Apr-06 17:26
457 Gabriele and, it's a few lines of code (half a page or so) 28-Apr-06 17:25
456 Gabriele it turns out that i can do tree rewriting as a subset of dialect rewriting. it's a bit tricky but works well. 28-Apr-06 17:24
455 Ingo I once used XML as a file format, just to play around with it. And later I found out, that I'd broken so many rules, that no other gram was able to read it anyways. ;-) 28-Apr-06 16:43
454 Ingo I guess people have _very_ differing needs in this. Some _really_ need to handle XML with all strings attached to it, and others just want to interface to existing technoglogies and read / write xml. I'd put myself in the second category, if ever I have to work with XML again, that is. And I surely hope this won't happen ;-) 28-Apr-06 16:42
453 MichaelB Jaime: that's what I meant too. But the discussion jumps around quite a bit and as some of these terms are unfamilar (besides the simple I know what you're talking about) - it's hard to know what to vote for :-). 28-Apr-06 16:35
452 Pekr this group exists for a long time, and IIRC initially we were more or less discussing rebol - XML interoperability - SAX or DOM parser in rebol .... while from what is being discussed now, sounds like slightly bit different topic? 28-Apr-06 16:34
451 Pekr that sounds good ... so far my only experience with XML in rebol is Gawain's work - better than nothing .... but what exactly do you mean by XML here? 28-Apr-06 16:33
450 JaimeVargas I think Gabriel proposal is to rewrite the XML into an RXML "A easy to manipulate representation of XML in rebol". Then you rewrite back to XML if you need to. 28-Apr-06 16:27
449 Pekr I agree to MichaelB .... but maybe then I vote for 1, 2 and 3 as well, so that 3 can be translated to "standard" 28-Apr-06 16:25
448 MichaelB Actually I don't care what directly is available (as a user), if just some things can be done: e.g. people need to process XML - thus people already knowing XSLT and XPATH would like to leverage their knowledge (I asume) - so if we get a dialect for this (2.) this is nice, but even nicer if there is some mechanism (a generalization) which allows to import an XSLT (ast?) or some XPATH query and return the (more rebolesque) according Rebol dialect 3. three has always this kind of attitude of being able to do everything better in Rebol itself - even if true (?), that's one of the problems with Rebol, that outsiders can't afford the time to do many things better (themself) or don't care, because they want use some standards nevertheless and Rebol drops out as an option
so I vote for 2. with the ability for 1. maybe by the possibilities tree rewriting (or dialect rewriting) offers (I have not much glue about this - so some of the experts should know)
28-Apr-06 16:16
447 JaimeVargas BTW, Gabriele you have my vote on tree rewriting. 28-Apr-06 15:43
446 Pekr maybe, but maybe not. We need to be able to interface XML (DOM) anyway .... (e.g. for plug-in ) 28-Apr-06 15:09
445 yeksoon the lack of vote for xpath and xslt..
maybe its because there is this thought of adding yet another layer just to manipulate the data etc (remember Carl's slide in DevCon 2004 ?... with REBOL on one side against a stack of others on the other side)
28-Apr-06 14:43
444 Pekr maybe noone votes for 3 because a) we have little understanding what xpath can do for us b) once we say "dialect" or rebol in general, we sometimess think it is cure for all proglems 28-Apr-06 14:23
443 Anton Hmmm..... 28-Apr-06 14:22
442 JaimeVargas But by avoiding the AST aren't you throwing the possibility for optimizations, a direct rewrite engine is more like a literal translator. The cool think of having an AST is all the tricks that you can play to produce more efficient code at the cost of pre-processing time. 28-Apr-06 14:19
441 Gabriele i don't know if this concept can be generalized easily. but it would be interesting to figure out. 28-Apr-06 14:15
440 Gabriele so it can be considered a superset of tree rewriting (since you can think of a dialect to represent trees) 28-Apr-06 14:14
439 Gabriele dialect rewriting is basically what my rewriting engine for rebcode does; it's rewriting where instead of using a regexp you use a parse rule; and instead of compiling a tree to another tree you compile a dialect to another dialect. 28-Apr-06 14:14
438 Gabriele there are only two votes so far, howeverr both voted for 3. maybe, we could introduce a new concept to CS, "dialect rewriting". :) it's the same as tree rewriting but without a tree. ;) 28-Apr-06 14:11
437 Gabriele xslt does something very similar; it matches a number of nodes (via xpath), then creates a new tree based on those nodes. rules are applied recursively so that you end up with a new tree starting from the initial tree. 28-Apr-06 14:09
436 Gabriele no, you specify a pattern that can match a subtree, and replace that subtree with something else. 28-Apr-06 14:08
435 Maxim ok, so you pre-specify how path /aaa/bbb/ccc/ specifies data in another tree /xxx/yyy/zzz ? 28-Apr-06 13:32
434 Gabriele "Tree rewriting is a model of computation which is used in a variety of contexts within computer science, for example in semantic specification and compiler implementation" 28-Apr-06 10:12
433 Gabriele basically, you have a tree, and you have a set of rules for rewriting; a rule is a pattern and a replacement for the matched node 28-Apr-06 10:09
432 Gabriele max: tree rewriting is the technique that compilers use to get from the source AST to the final machine code; you can also imagine purely functional languages as special tree rewriting engines. 28-Apr-06 10:07
431 ScottT well, if you can write a stylesheet that outputs a layout. Not at all impossible, <xsl:output method="text" /> 27-Apr-06 20:49
430 yeksoon does having XSLT also means we can map that into /View? 27-Apr-06 19:08
429 Maxim can you further define "tree rewriting" 27-Apr-06 16:40
428 Gabriele "we already have data as trees" - if you use that, then tree rewriting would be very useful for you, wouldn't it? 27-Apr-06 16:18
427 Maxim so my vote 3) 27-Apr-06 15:23
426 Maxim although getting XML:schema LOAD/SAVE , complete, native XML 1.0 LOAD/SAVE that would at least allow us to start using XML in the first place ;-) 27-Apr-06 15:23
425 Maxim and we already have data as trees in rebol, nested blocks and objects... so I don't think its going to help much. 27-Apr-06 15:20
424 Sunanda I'd lead towards 3. But that's because I heft XML into REBOL objects and fiddle with it from there. That gets away from the strict hierachy of XML, so I don't need to think about basically insane things like XSLT's axis processing 27-Apr-06 8:14
423 Gabriele i'm just trying to get some ideas. not a real poll. but maybe we can post this on reboltalk too. 27-Apr-06 8:09
422 yeksoon why not post this on REBOLTalk.com forum as a poll?
have AltMe, ML user participate in this poll
27-Apr-06 7:58
421 Gabriele (pick your choice :) 27-Apr-06 7:46
420 Gabriele 1) people want XSLT and XPath in rebol, because it's the standard and so on. 2) people want a dialect that offerst XSLT/XPath-like functionality to work on REBOL trees (as opposed to XML) 3) noone cares about representing data as trees in REBOL because dialects are much better anyway 27-Apr-06 7:46
419 Gabriele speaking of XPath (Reichart's msg on Altme group), I wonder if there's need for it in the community? 27-Apr-06 7:44
418 Maxim it seems powerfull, but I had a hard type getting it to work. I WAS pressed for time though. 26-Apr-06 16:29
417 Joe I used Gavin's code in the past and found very complete and useful, specially when using xml-object.r 26-Apr-06 16:27
416 Maxim its easy to use? and will get your job done within minutes of trying. ;-) 26-Apr-06 16:26
415 Joe How does rebxml compare to gavin withead xml-parser.r ? 26-Apr-06 16:25
414 Geomol Great to see my work is being used! :-) 26-Apr-06 11:08
413 Maxim also, although I have not looked at rebelxml in this regard, rebxml handles many of the xml idiosyncracies in the XML specification like empty tags, CDATA blocks, and some level of character conversion to handle unicode and & escaped chars. 25-Apr-06 21:06
412 Maxim rebxml can be found here, with docs :-)
http://home.tiscali.dk/john.niclasen/rebxml/
25-Apr-06 21:04
411 Graham Where's your script ? :) 25-Apr-06 21:03
410 Maxim that's my 2 cents. and a 2 minute overlook of rebelxml.r 25-Apr-06 21:03
409 Maxim I must admit that just by looking at the docs, I prefer Geomol's solution better, its more approachable. 25-Apr-06 21:02
408 Maxim Its news to me, but in my useage, Its easier for me to have rebol loaded blocks, cause I can use path notation directly, in order to access the data, just as if they where objects. 25-Apr-06 21:01
407 Graham what do think of this new script ? 25-Apr-06 21:00
406 Maxim I'm using rebxml as the loader and then write a dialect over it to convert to my preffered (easier to use) block format. 25-Apr-06 20:59
405 Graham ( I know nothing really of XML .. just know I have to parse some data, and rewrite out my data as xml ) 25-Apr-06 20:58
404 Graham which is best to use? 25-Apr-06 20:57
403 Graham what's the difference between RebXML, and rebelxml and other implementations? 25-Apr-06 20:57
402 Graham there's a new script in the library %rebelxml.r ( not sure why it isn't rebolxml.r ) 25-Apr-06 20:56
401 ? We have done a little in Qtask. WE save the tasks as XML (and call it XLS so that Excel can load it). We will be writing an RSS reader soon. 21-Apr-06 8:25
400 Maxim anyone know if any XML Schema integration has been done in REBOL? 20-Apr-06 20:41
399 Maxim Geomol, you might just have made yourself a new user :-) I'll try to stress-test RebXML next week, gauging speed, features and stability. 13-Apr-06 14:36
398 Geomol Maxim yes, RebXML can handle namespace tags and unicode. 13-Apr-06 11:08
397 Allen I always thought the c in W3c meant committee not consortium. ;-) 13-Apr-06 0:52
396 ? "my god reading the w3c spec for XML is insane." LOL 12-Apr-06 22:20
395 Rebolek pekr: no wonder there's still no fully compliant xml parser 12-Apr-06 14:21
394 Pekr no wonder what? 12-Apr-06 14:10
393 Maxim reading the xml spec... its no wonder. 12-Apr-06 14:07
392 Maxim yep. 12-Apr-06 14:05
391 Pekr hmm, I think that our problem is not lack of speed, but lack of fully compliant xml parser at first.... 12-Apr-06 14:05
390 Maxim I want to try out with rebcode one day. it would probably go about 10 times faster or more. 12-Apr-06 14:04
389 Maxim it does all in one shot. I read through the string once and have a nifty recursion with tail handling. 12-Apr-06 14:03
388 Pekr does it work SAX way or DOM way? I mean - load first, then parse, or parse while reading way? 12-Apr-06 14:02
387 Maxim yet builds a nested block of blocks much like RebXML. 12-Apr-06 14:01
386 Maxim my tool currenctly loads 1MB of xml tags in under a second. its almost as fast as load/markup. 12-Apr-06 14:01
385 Maxim it had to do with http dowloading of the chunks... 12-Apr-06 14:00
384 Maxim but there where some errors in the datafile itself, in the begining. 12-Apr-06 13:59
383 Maxim my own when I started the project I did not have many days to "get on with it" and for various reasons all the tools I tried didn't properly load the specification I was trying to load. 12-Apr-06 13:59
382 Pekr maxim - have you used Gawain's xml parser, or is it your own one? 12-Apr-06 13:58
381 Maxim Geomol, just looked over rebxml... I've build a similar engine, even simpler actually. but it might become a little bit smarter in a few weeks... maybe supporting more of the XML 1.0 specs like &chars conversion and such. 12-Apr-06 13:57
380 Maxim geomol, does RebXML handle namespaces and unicode? 12-Apr-06 13:53
379 Maxim saved out a 15 cell spread sheet in microsoft xml yesterday... 58kb of data HAHAHHAHAHAHAHA 12-Apr-06 13:52
378 Geomol If you choose to have your doc formats in something like the XML-based OpenDocument, where every tag is explained in an open specification, then it can be used. (Only problem then is XML itself with it's problems.) 12-Apr-06 9:54
377 Geomol I remember talk a few years ago, that MS would make their .doc format XML based. And people thought, that would mean, it would become an 'open' format, which could now be read and written by any wordprocessor. If you have somehing like: #{78797A7138373837} in binary, and choose to make it into XML: <xyzq>8787</xyzq> does that make you know, what it mean? No, of course not. Some MS employee later told in an interview, that MS of course would guard their IP - 'intellectual property'. I don't know, where the story ended, and I don't care much, as I keep away from MS formats. 12-Apr-06 9:49
376 Pekr I think that current situation of XML world shows, that it is rather absurd situation .... the idea of automatic exchange of docs, their specs, without involvement of ppl, is naive .... 12-Apr-06 9:39
375 Geomol If you need a simple XML spec, don't forget my RebXML: http://home.tiscali.dk/john.niclasen/rebxml/ (Only a couple of pages.) It's an easy way to work with XML inside REBOL, and on the same page you'll find scripts for converting between XML and RebXML. 12-Apr-06 9:35
374 Pekr not to mention browser incompatibilities, because in the case of XML, browser is your "preview" interface ... 12-Apr-06 9:06
373 Pekr I think not, Graham .... we have such a problem ... big corporation, we try to define xml formats. The trouble is, big products do wrap it for you, but what about smaller companies? 12-Apr-06 9:06
372 Graham Possibly an exaggeration on their part. 12-Apr-06 8:45
371 Graham I'm on a list discussing, inter alia, CCR .. which stands for continuity of care record. It's XML, and so guys are saying it's taken them 50,000 lines to write the parsing code etc. 12-Apr-06 8:45
370 Allen I think that might be why the microformats are taking off. They use XML in its simplest, intended form. 12-Apr-06 8:17
369 Allen XML was a simple 2 page spec originally. 12-Apr-06 8:16
368 Sunanda XML was intended to be a simplification of SGML. But they forgot to ask first "why is SGML apparently some complicated?" So they ended up adding back in most of the complications in an ad hoc way. 12-Apr-06 7:42
367 Maxim XML overcomplicates soooo many things. its like the standard, for people who can't make up their minds:
You can do this, or that or this too, but only when this and that or this occur outside and inside that other thing.
12-Apr-06 6:02
366 Maxim my god reading the w3c spec for XML is insane. 12-Apr-06 5:59
365 Th�r manual resync... 4-Apr-06 18:19
364 ? Agreed. So, write a Rebol block ML that does everything as well as XML, and we will support it. 23-Mar-06 19:25
363 Anton no need to convince us :-) 23-Mar-06 15:46
362 Maxim I left the tabs at 2 spaces in the rebol output, so that the comparison is fair. 22-Mar-06 17:46
361 Maxim 693 kb in xml form ==> 90 kb in nested rebol blocks 22-Mar-06 17:43
360 Maxim an empiric test (subjective to the xml structure and tag names obviously, but this IS a real world xml file) 22-Mar-06 17:41
359 Maxim xml is such bloat.. I am parsing xml these days and for two characters of data, I often have a 100+ characters of nested stupidity. 22-Mar-06 16:47
358 Will http://tech.motion-twin.com/xmllight.html 8-Jan-06 23:58
357 Christophe Has somebody already give a try to a SAX implementation ? 27-Nov-05 13:15
356 Maxim will be reading top to bottom ... not that this is any fun... ;-) 15-Nov-05 3:49
355 Maxim thanks Chris ! 15-Nov-05 2:45
354 Chris http://www.w3.org/TR/REC-xml/ 14-Nov-05 5:27
353 Maxim out of the blue, can anyone point me to the (or one) official XML spec ? (if there are many, it should be the one most used on windows and in things like PHP)
thanks!
14-Nov-05 1:30
352 Volker I guess in rebol we have fewer problems than java, as rebol is dynamic and java has to emulate that? So it cant map its own classes because the format is not known at compile-time? While we can. And then xml in memory should be in the order of rebol-blocks? 12-Nov-05 11:15
351 CarstenK DOM: in java APIs there were allways problems with dom - big amount of memory, not optimized for a language, so there was a need for optimized tools like JDOM, XOM or DOM4J, they all prefer SAX for parsing and have their own internal model - of course the API is special for all these tools and no standard like DOM 12-Nov-05 11:11
350 CarstenK in the moment i play a little bit with xml-parse.r, it has a lot of things done, some are still open (like <!ENTITY ...> parsing) and it is like SAX - I try to implement some handlers to learn REBOL, but it's still in progess. A benefit of xml-parse is, that there would be only one parser and some kind of standard API and the handler could then generate rebxml or some other desired format 12-Nov-05 11:08
349 Volker xml is used to store word-files, rebol not? :) 11-Nov-05 19:42
348 Chris Any less than you'd want a 10mb Rebol interchange file? What % of cases would this be an issue? 11-Nov-05 19:36
347 Pekr hmm, couldn't we just somehow mix the aproach, so to have some streamed dom? :-) I don't like the idea of having 10MB XML interchange file to load into memory .... 11-Nov-05 18:40
346 Chris Using DOM methods, you can do this albeit clumsily, but completely. All through a set of standard functions, with no need to manipulate the structure directly. 11-Nov-05 16:46
345 Chris But this is the issue here with Rebol and XML, there are solutions that suit one XML operation or another. Aiming for loosely implementing DOM gives us loading, extraction, modification, and saving without affecting the integrity of the data structure. Examples: changing the title of an HTML page, adding an entry to an RSS file, etc. 11-Nov-05 16:44
344 Geomol RebXML is meant for conversion to/from the RebXML format and other formats (incl. XML). I use the RebXML format with NicomDoc, which makes it a lot easier to handle document formats. Let's say, you've got an XML file, and want to convert it to a format easily read by some application, then you first use xml2rebxml to get the XML file to RebXML format. Then make a converter from RebXML to the final format by renaming the rebxml2xml script and change it to do the output, that is wanted. rebxml2xml holds the structure of the RebXML format, so it's easier to start with that script. Search for "output" in rebxml2xml. Maybe I should make a converter from RebXML to some format very easily manipulated directly within REBOL, like the python tool, Carsten found. 11-Nov-05 8:50
343 Chris I've also noticed a tendency to kick the DOM (no doubt for good reason) -- though worth noting that it is a complete api to xml and it is a standard api, I wouldn't underestimate the value of the latter, particularly when it comes to Rebol advocacy... 11-Nov-05 4:50
342 Chris note: this group isn't showing on the web site, is this due to [web public] instead of [web-public] ? 11-Nov-05 4:46
341 Chris Catching up a little. Be interesting to summarise this thread as there are many different ideas expressed. rebxml looks interesting for loading, saving and likely extracting xml, but still perhaps difficult to manipulate. 11-Nov-05 4:43
340 CarstenK John: Thank you, I'll play with it.
I found this python tool - maybe some interessting ideas there: http://uche.ogbuji.net/uche.ogbuji.net/tech/4suite/amara/quickref He uses objects but I like the idea for accessing xml - replacing the dots with slashes it looks for me like REBOL: doc/a/nodeName doc/a/b/1 ... doc/xml
9-Nov-05 13:53
339 Geomol total-length? will count elements, and another block is also an element. 9-Nov-05 13:49
338 Geomol Carsten, a recursive function to count length of blocks with nested blocks:
total-length?: func [b [block!] /local n] [ n: 0 foreach e b [if block? e [n: n + total-length? e] n: n + 1] ]
9-Nov-05 13:47
337 CarstenK With length? i need some recursion, otherwise I get only the first level of the block if it is nested? How to serialize an object tree in REBOL - is there some function available? 9-Nov-05 13:41
336 Geomol About encoding in RebXML, rebxml2xml let you produce utf-8 by specifying the /utf-8 refinement: rebxml2xml/utf-8 <some rebxml data> 9-Nov-05 13:41
335 Geomol About memory for block or object, If you mean in bytes internally in REBOL, I don't know. But you could save the block or object to a file and see a size that way. You can of course see the length of a serie with: length? 9-Nov-05 13:38
334 CarstenK I have no idea about comparision of XML documents (input and output of rebxml for instance ) to ensure correctness, but it seems to be difficult. 9-Nov-05 13:37
333 CarstenK RebXML: I did some testing with rebxml, the documents I used can be found here: http://www.simplix.de/rebol/resources/xml/xmltests.zip There is also a simple script that reads the XML docs in and writes them back.
Some problems I found: - empty attributes, I have fixed this in the zip - entities in content: all should be escaped, because they can be found there, otherwise a " gets &quot; - comments after last element missed - comments before first element - missing line feed - missing PIs in output
Another question: encoding - it seems that all output files will be written in iso-8859-1 ?
9-Nov-05 13:36
332 CarstenK I've also had a look inside xml-parse, it seems to be really like SAX - ready to use. But nobody is maintaining it, I think. As far as I understand, somebody could create a Handler to get the desired block structure (for instance a Handler for RebXML or any other model). I have to learn about this in REBOL.
A question: how can I measure memory for a block or an object tree in REBOL?
9-Nov-05 13:30
331 Christophe hum... i will digg a little more into the the theory i think. I had learnad another approach to that. Thanks anyway for showing the way ! 8-Nov-05 21:49
330 BrianH No, parse-xml generates a (broken, incomplete) DOM tree. Gavin McKenzie's xml-parse is more like a SAX parser. 8-Nov-05 21:47
329 Christophe Did you have a look at the source of 'parse-xml ? Is this what is meant to be event-driven ? 8-Nov-05 21:41
328 CarstenK John: I''ve downloaded the scripts and will check them. 8-Nov-05 20:00
327 BrianH (abut = about) 8-Nov-05 19:28
326 BrianH The important thing is to make sure that the events or data structures are a good map of the semantic model of XML. They have standards abut that too. 8-Nov-05 19:28
325 BrianH Those tag "/bbb" end tag events might be better named closetag "bbb" since close tags aren't supposed to have attributes anyway. 8-Nov-05 19:25
324 BrianH Balancing the detail of the events against the function-call overhead of the language may be appropriate. One advantage to SAX-like apis is that you can register handlers for certain events and ignore others you aren't interested in, making your code even more efficient. 8-Nov-05 19:22
323 BrianH As for that data, let's assume a normal, fine-grained model. I'll just list the events:
tag "aaa" attribute "attaaa" "aaa1" end tag tag "bbb" end tag "contentbbb" tag "/bbb" end tag tag "/aaa" end tag
If you use a more coarse-grained model, you could have an event for a whole tag, its attributes, namespaces and such, rather than seperate events for each. This might be more appropriate for a more powerful language like REBOL. Fine-grained events are really more appropriate for languages with poor data structure support, like C or rebcode.
8-Nov-05 19:19
322 Christophe So we can call it RebSAX approach :-)) ? 8-Nov-05 19:13
321 BrianH If you say "I want to do a SAX-style XML parser", you mean event handling. Other data models have their own apis to copy, or don't so you have to come up with something new :) 8-Nov-05 19:09
320 Christophe Ok, I'm not a SAX specialist :-/ for my understanding, could you give an example of how <aaa attaaa="aaa1"><bbb>contentbbb</bbb></aaa> should be SAX-handled ? 8-Nov-05 19:09
319 BrianH The only difference is whether it is push (callbacks) or pull (state machine, I think). 8-Nov-05 19:08
318 BrianH For SAX, the event handling is the data model, the whole thing that makes it efficient. 8-Nov-05 19:06
317 Christophe I thought SAx was about finding the most suitable data structure - not a tree representation, which is DOM. I don't know if the event handling part is mandatory (BTW, to whom ?). isn't all about accessing XML data the best way a PL can ? 8-Nov-05 19:04
316 BrianH SAX apis don't work like that. They generate a series of events, not a series of data. 8-Nov-05 18:51
315 Christophe Has anybody think about a rigth data structure to use with a SAX-implementation ? I was thinking of the hash! and its performence for level 1 data retrieval. Perhaps an appropriate data structure could be a binary array labeling each element with a concatenation of the access path. Like this: <aaa attaaa="aaa1"><bbb>contentbbb</bbb></aaa>
becomes
make hash! [aaa id2 aaa-attaaa "aaa1" aaa-bbb "contentbbb"]
based on a mapping table
make hash! [id1 aaa id2 bbb]
or something similar...
just a rough though !
8-Nov-05 18:49
314 Christophe Carsten: "how different is EasyXML from rebXML?" I don't know :-) The most of our REBOL development is conditioned by the need of my job. Now I need an easy way to access to the parsed data. Xpath is an easy way. So we are creating a structure which facilitate the access to nested data. And it's fun :-) Now it could be john create something similar, and that we like it and adopt it. Who knows ? 8-Nov-05 18:41
313 Geomol Carsten, I've uploaded new versions of the RebXML scripts to: http://home.tiscali.dk/john.niclasen/rebxml/ Comments are now handled as strings, they are simple preserved without modifications, and in rebxml2xml I then check for " ** Near: (line 9) -->
So I replaced insert tail output load join "<!--" data with insert tail output join "<!--" data and it works fine with my files!
You were right, the replacements in text nodes are only & > <. In attributes we need to escape the other 2 entities as allready done by you.
7-Nov-05 20:31
285 CarstenK ... using a XML port 7-Nov-05 20:30
284 CarstenK to michael: maybe you can show some rebol pseude code, how to read all chapters from a book.xml file, so we had some nice use case to think about 7-Nov-05 20:30
283 MichaelB carsten: I should have kept my mouth shut about XOM and asked you before :-) the port-idea was just that a thought - in any case if one wants to use a dialect there has to be an entity to interpret the dialect, whether that's an function or something else doesn't matter, but a port seams to be a common rebol entity to encapsulate things - that's why I thought it would maybe even make sense to use a port as abstraction .... opening a port to an xml file and the port will parse it in whatever way - by sending (inserting) a dialected block into the port the xml document could be worked on - at least from the users point of view one wouldn't have to handle the xml-code-block/rebol code block separetely - even though it might be nice to access it directly .... well maybe I have too little glue about ports so the idea might not make too much sense when I forgot about some important drawbacks and the like 7-Nov-05 20:17
282 Graham lol 7-Nov-05 19:53
281 Volker Hat-man? :) 7-Nov-05 19:52
280 Geomol He's like a Marvel Super Hero! :-) 7-Nov-05 19:49
279 Christophe Gregg: as fast as lightning :-) 7-Nov-05 19:14
278 Gregg Done. 7-Nov-05 19:02
277 Pekr Gregg - I think no problem here to make it web-public ... 7-Nov-05 19:01
276 Gregg Should this group be web public? 7-Nov-05 18:57
275 Christophe rebcode could be an issue. But still under development .. 7-Nov-05 18:20
274 Christophe Volker: i got your point. I don't know yet. I will study it tomorrow. 7-Nov-05 18:20
273 BrianH Or for that matter, block parsing. 7-Nov-05 18:13
272 Volker And with blocks there is a better chance to use rebcode? 7-Nov-05 18:02
271 Volker but 10-20% is not much anyway. 7-Nov-05 18:01
270 Volker because you can use an object as long as there is only one value. But not sure if that helps. 7-Nov-05 18:01
269 Christophe I do not get where you gain in performance? Or do i get it wrong ? 7-Nov-05 17:56
268 Volker A rough idea: Maybe like vid does it? /color /colors ? it puts the first color in color if there is only one. if there are more, they are put in /colors-block . 7-Nov-05 17:54
267 Christophe I was fighting today to find the best internal data format. Out of the tests seems object! the most performant when using nested data structure. hash! when not nested. but the problem with object! is that we cannot have a recurrent element in the structure, like: <aaa> <bbb>content</bbb> <bbb bbb_attrib="attrib1"></bbb> </aaa> because, of course, when evaluated the last definition of bbb overrides the others. So, we are trying to work with hash! We got a little diminution of the overhead comparing to XML, but the processing time compare to block! seems from 10 to 20% more. I need some more tests about data retrieving in the structure to find the right combination; Any suggestion is welcome ! 7-Nov-05 17:50
266 Christophe Geomol: you've done a great job with your rebxml. But we really need some kind a dialect to easilly acces nested data. Like Xpath... I need to be able to say get-data [//*/bbb/ccc[@id='geek']] and get the info. I think xpath have a great notation for that (and a standard). So e have to find the format wich best fit this dialect... 7-Nov-05 17:18
265 Christophe MichaelB: about unicode handling. That's a point we didn't think about, because we're working in iso-8859-1 (western european) and not utf-8 or-16. So we've to see what would the cost be of it. If here is any suggestion about how to handle this, those are mostly welcome ! (I handled a similar problem with a simple replace/all, but i don't know if it's the best approach) About a port-approach... What should be the advantages ? 7-Nov-05 17:13
264 Christophe Pekr: I do not know XOM, i will study it. Maybe it fits beter than our idea of DOM. 7-Nov-05 17:12
263 Christophe Well this is a great place to learn ! 7-Nov-05 17:12
262 Pekr Thanks Carsten, that clarifies things clearly to me .... I like Sax aproach more too .... IIRC Gavain's stuff was Sax like too ... it just could not write back to XML ... 7-Nov-05 12:26
261 Geomol Carsten, to insert second sect1, do something like: append last my-doc [sect1 id "sct_about" name "Another about" [title "etc....."]] 7-Nov-05 12:23
260 CarstenK To Michael: I'm not sure if need DOM and SAX, there problem is, that the commitee tried to develop language independant interfaces - so both APIs have problems in the targeted programming language. DOM is inefficient, and you should avoid it. The best way seems to be: 1. have a parser like SAX with events 2. build the model in the best way for your language 3. provide a API for your language Basically XOM does it for JAVA very well, E.R.H. uses a SAX parser and converts to its own object model that is optimized for java. For REBOL this should be something like a block, I think. (Blocks are best way to store things in REBOL ?). But thats internal side of the the tool and could be the rebxml block structure. As api there should be a dialect, maybe one that uses a port (there I have less knowledge - have to learn about this). 7-Nov-05 12:13
259 CarstenK John, I've downloaded it from your website - thank you!
One more question from an unexperienced REBOL-user: What is the most commen way to enhance a block I've got with xml2rebxml, source is <?xml version="1.0" encoding="iso-8859-1"?> <chapter id="ch_testxml" name="Test XML"> <title>A chapter with some xml tests</title> <sect1 id="sct_about" name="About my Tests"> <title>What kind of tests I will do</title> <body> <para>Some simple paragraph.</para> </body> </sect1> </chapter>
After read in the file with my-doc: xml2rebxml read %test.xml I'd like to insert a second sect1-element in the block my-doc, whats the best way - just to avoid some stupid mistakes.
7-Nov-05 12:05
258 Geomol Carsten, I've added suport for " and ' in xml2rebxml. I've also added preservation of comments, if xml2rebxml is called with /preserve refinement (just call it like: xml2rebxml/preserve <xml code>). I've uploaded the scripts to my page: http://home.tiscali.dk/john.niclasen/rebxml/ I think, they need some testing, before they go to the library at www.rebol.org. 7-Nov-05 11:41
257 MichaelB Would it make sense to have XML files be represented as a port like xml:// . This could make sense for DOM and for SAX. But please correct me if that's stupid. For SAX this would enable one to copy from the port and get events by copying, for some one could navigate with some dialect and position the cursor in the document. A copy would read the data at the current positon - but then a block or something which represents an element could be returned. But I guess that's not well thought out. :-) 7-Nov-05 11:36
256 MichaelB As Christophe told on the mailinglist - we actually need both SAX and DOM, because if you have a large document and are only interested in a sequence of appearings of elements one at a time, you don't need DOM, but if you need information about the overall structure of a document you have to read in the whole document and that's DOM. But if Christophe is doing DOM already - don't know to what extend - this would be very nice and might be ok for now. 7-Nov-05 11:32
255 Pekr I liked the discussion Chris and Brian hold here week or so ago ... simply let's find a way of how to work with XML in rebol - once we know what do we want, we can start coding ... 7-Nov-05 11:23
254 MichaelB For sure we shouldn't try to simply port something. But maybe it's anyway better to see what Christophe (Coussement) is doing (or his team). But XOM as a base for ideas might not be bad, as it's well designed based on some simple principles which I would sign at least. But it's completely object oriented, so there might be a more Rebol like way to go - don't know. What I would be interested to know is how Christophe is going to handle Unicode files? There are some scripts to help converting utf8 and the like, but I can'f oversee right now how well this will work. 7-Nov-05 11:19
253 Pekr hmm, not so easy and small anyway ... probably the best aproch will be to decide what direction we go and then starting to build rebol-oriented solution, not trying to port something. Looking at some stuff it seems to me sometimes it is designed to fit target language, e.g. java .... 7-Nov-05 11:13
252 Pekr I seem to like XOM, at least upon what author says about it - of course, he eventually might be biased towards his own work - http://www.artima.com/intv/xomdesign.html - if it is true that simplicity was his motivation, then we could look into XOM as possible way to go ... 7-Nov-05 10:40
251 Pekr http://www.artima.com/intv/dom.html - The Good, the bad and the DOM - "a camel is a horse designed by committee" :-) 7-Nov-05 10:30
250 Geomol Carsten, you're right about the " and '. As I read the DTD (http://www.w3.org/TR/2004/REC-xml-20040204/), those can only be found in attribute values (see [10] AttValue), not in character data (see [14] CharData). Is that correct? 7-Nov-05 10:30
249 Pekr What is wrong with XML apis - http://www.artima.com/intv/xmlapis.html 7-Nov-05 10:10
248 Pekr at xom.nu, you can find various articles too ... 7-Nov-05 10:09
247 CarstenK I will try the new xml2rebxml.r, I think it would be nice to preserve the comments. If somebody writes xml in a text editor and makes some annotations, so it its nice, if he gets these comments back after processing the files with some other (REBOL) tool. But this feature has some lower priority. I found some more thing in xml2rebxml.r, only the entities replace/all att-data ">" #">" replace/all att-data "<" #"<" replace/all att-data "&" #"&" will be replaced, the other two are missed, I think: replace/all att-data """ #"^"" replace/all att-data "'" #"'" 7-Nov-05 9:55
246 Pekr taken from ML - http://www.xom.nu 7-Nov-05 9:02
245 Geomol I've uploaded the script to the library. 6-Nov-05 18:35
244 Geomol Carsten, the script still strip comments. Do you need the comments to be lead through to the output? (I'm a bit in two minds about, how it should work.) 6-Nov-05 18:24
243 Geomol Carsten, ok I found a bug related to multiple comments after each other. Get fixed script here: http://home.tiscali.dk/john.niclasen/rebxml/xml2rebxml.r 6-Nov-05 18:22
242 CarstenK cool, thank you for your time! 6-Nov-05 18:06
241 Geomol Carsten, yes, I get the same problem here. I'll look into it. 6-Nov-05 18:03
240 CarstenK I played around with some shorter XML document, to figure out, how it works - my REBOL experiences are from last week, so maybe I'm doing something wrong. The comments will be parsed and the block looks also complete but during writing it stops after an element that is followed by some comments. So far as I have seen these comments are left out in the block but there are a lot of whitespaces between the last printed element and the next missing element. 6-Nov-05 17:47
239 Geomol By "handle", I mean parse them, but comments ain't in the output. The script shouldn't stop for valid XML input. 6-Nov-05 17:40
238 Geomol Carsten, xml2rebxml should be able to handle comments. Are you sure, your simple.xml is valid xml? 6-Nov-05 17:34
237 CarstenK One more thing about XOM: E.R Harold has collected a lot of test XML files with many sophisticated XML things that can happen regarding to the XML 1.0 specs. 6-Nov-05 17:33
236 CarstenK Doing my first steps with REBOL I tried to do something with XML (reading/eventually modifing/writing). I looked for some scripts helping me to do this and found:
1. xml2rebxml/rebxml2xml: I got the following problems: - missing/loosing comments - missing/loosing elements - that's realy serious my steps were: my-doc: xml2rebxml read %simple.xml write %simple2.xml rebxml2xml my-doc
The second documents finishes outputting elements after some comment block in the source xml doc.
2. xml-parse/xml-object: The versions I found on the reb library didn't work, I used some older versions from rebXR-1.3.0, I've got my objects, but it would be nice to have a third module like xml-write to get the object tree back to xml. Is somebody developing something like this?
3. mt.r: I tried to figure out how it works. Basically I can write some XML based on a REBOL block but I couldn't figure out how to define the rules about elements and attributes. Where can I find an example about writing for instance svg with mt.r, how looks the coresponding REBOL block and the rules for svg?
Where can I find more about xml and REBOL, I think it would be very nice to have some REBOL scripts, doing things like some-elem: xml-create [ elem "foo" namespace "myns" attribs [ bar "something" xyz "123"] ] xml-modify [ elem another-elem append some-elem ] and finally xml-write %mynewxml.xml my-doc
Is somebody developing something like this with REBOL? Some scripts giving me the same comfort in REBOL like maybe XOM (http://www.xom.nu) is giving for XML in Java. Of course done with some nice REBOL dialects? What is the above mentioned "EasyXML" - is it available for use/testing?
Thank you for any tips, carsten
6-Nov-05 17:19
235 Pekr We should choose the way of how we integrate it into rebol - SAX, DOM, other ... 5-Nov-05 17:25
234 Pekr look at Technews - E4X for Javascript - I like the simplicity they integrated it into the language .... 5-Nov-05 17:24
233 JaimeVargas (Continued in the !Beer group...) 2-Nov-05 18:20
232 Graham Well, I would like to know as otherwise it's very insecure at present :( 2-Nov-05 18:15
231 JaimeVargas Complete LNS when we have the final spec. 2-Nov-05 18:15
230 JaimeVargas Nope. There is a way around this. Without your fudge. 2-Nov-05 18:15
229 Graham So, when are you guys going to complete LNS ?? 2-Nov-05 18:14
228 Graham But if someone had the source, they can pretend to be an administrator, and start to damage my data :( 2-Nov-05 18:14
227 Graham At present I fudge it by asking initiators to send a userid with each request so I can determine their rights. 2-Nov-05 18:13
226 Graham oh... well, I may have to backtrack on that .. it could be dangerous to release the source code while LNS doesn't have a way to restrict access to functions. 2-Nov-05 18:12
225 JaimeVargas I mean the src code? 2-Nov-05 18:11
224 Graham up to 0.0.70 now. 2-Nov-05 18:11
223 Graham It's being continually released all the time. 2-Nov-05 18:11
222 JaimeVargas BTW. When are you releasing your medical application? I guess is going to be open-source due to GPL licensing issues ;-) 2-Nov-05 18:08
221 Graham No... just thinking about an upcoming code review :) 2-Nov-05 18:05
220 JaimeVargas Do you want Rebol to run C code? 2-Nov-05 18:03
219 Graham How hard would it be to write a C to Rebol translator ? 2-Nov-05 18:01
218 JaimeVargas With a support contract. 2-Nov-05 17:59
217 JaimeVargas Better let the customer know what he is getting up front. Even if it is hards or sell the solution as closed-source. 2-Nov-05 17:59
216 JaimeVargas Pekr. I agree. But believe in the politics of truth instead of deception. 2-Nov-05 17:58
215 Pekr customers usually don't want to see a code ;-) And it is same like we coded with CA-VO ... we bought a library and did not care for its internals, if things worked ....:-) 2-Nov-05 17:57
214 Graham I guess you could then drag out dockimbels R# compiler 2-Nov-05 17:57
213 JaimeVargas C++ is now a language that is directly compilable. It doesn't go thru a translation to C. 2-Nov-05 17:56
212 JaimeVargas I can do a code review. And C++ is compilable by any standard compiler. 2-Nov-05 17:56
211 Graham C++ is a domain specific language which is then converted to C. Is there a difference? 2-Nov-05 17:54
210 JaimeVargas But the cosomter may ask to see the code. If you say your code is C. Then you are trapped? 2-Nov-05 17:53
209 Graham C source for Rebol is closed. 2-Nov-05 17:52
208 JaimeVargas What happens if the ask for a code review? 2-Nov-05 17:51
207 Graham Do what other people say - tell them you're using C :) 2-Nov-05 17:48
206 Christophe But we are Off topic here :-) Shouldn't we move to the "Chat" group ? 2-Nov-05 11:30
205 Christophe Yes, they want to be able to look forward. And REBOL stays "risky" in their critical eyes :-) 2-Nov-05 11:29
204 Pekr it is simply about feeling safe, so that IT manager can be sure and tell himself - look, someone other uses it too .... 2-Nov-05 11:26
203 Pekr well, try to keep up your good work. What is standard anyway? Or just make some calculation, how using different technology makes process more complicated/expensive (unless your opponents don't use other open-source technology, e.g. python) ... the bad thing is, e.g. here in our company, that the price is not always deciding factor. RT does wery bad job here. Our managers want to read some success stories, want to see list of other customers who do use such technology .... some case studies etc. Maybe simply Europe uses different kind of logic than US. 2-Nov-05 11:23
202 Christophe Since 2000, exclusively REBOL work! But I do not know how long I will be able to stand the position, because, despite the great results, we got a lot of opposition (not a standard, too cheap, no future, en so on...) :( 2-Nov-05 11:20
201 Pekr so you use rebol oficially at your work? That is nice. So far I used it only for few small utils here ... 2-Nov-05 11:18
200 Christophe FYI, I have set 2 ppl working on an implementation of XPath into our XML function lib (temporary called "EasyXML"). Basically, we'll have 5 functions encapsulated into a context: 'load-xml file!, 'save-xml file!, 'get-data path! or block!, 'set-attribute string!, 'set-content string! 2-Nov-05 11:17
199 Pekr yes, let's hope so, as then ashley can restart his work on otherwise excelent rebdb! :-) 2-Nov-05 10:30

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