[EMAIL PROTECTED] wrote: > > Ian Sparks <[EMAIL PROTECTED]> wrote: > > > > Mike Orr <[EMAIL PROTECTED]> wrote: > > > > > > XML is wonderful in theory, but in practice it takes something that > > > should be simple and makes it ridiculously complicated. > > Actually, depending on the nature of the data, the whole XML processing domain > encompasses things which can be quite difficult. When I made a statement > earlier about how XML is more than just an approach to representing data, but > actually a "movement" to solving certain kinds of problems more effectively, I > should have made the contentious-but-confident claim that there aren't that > many tools or technologies around that deal with "deep", hierarchical data > very effectively in the same way that relational databases provide robust > support for tabular data. (Of course, SGML has been around for years, so I > should qualify my claim by stating that there aren't that many "mainstream" > tools or technologies...)
Oh well, if you can't beat 'em, join 'em ... (yes, I'm the guy who said this whole discussion was off-topic, and I still think it is, but it's obviously not going away! ;^). No, XML *is* just an approach to representing data. IMO, the time was ripe for *any* general approach to representing data to become a gigantic trendy phenomenon, because of the Web and the state of computer technology (hardware, software, knowledge, etc.). The particular accidents that made XML the choice were (1) the existence of a huge lore of rigorous specifications and software for SGML and (2) the fact that everybody knew HTML. There are other approaches to representing data that are equally (or more) powerful, and that have equally powerful software associated with them. I will mention one: Express (ISO 10303-11). Express is a data definiton language (DDL) defined and used in the "STEP" standard (ISO 10303), a standard information model and exchange format for Computer-Aided Design (CAD), Product Data Mgt (PDM), Computer-Aided Engineering (CAE), and other engineering discipline models. There is an open-source (Lisp ;^) tool called "Express Engine" (http://exp-engine.sourceforge.net/) which can parse, validate, and create maps and views from Express schema definitions and data populations. The data populations are encoded using a format defined in ISO 10303-21, "Implementation Methods: Clear text encoding of the exchange structure". The maps (from an data population that conforms to Schema A to one that conforms to Schema B) and views are defined in the Express-X mapping language (ISO 10303-14), which I would suggest is at least as powerful as XSLT (and probably more powerful, since Express is a more powerful DDL than, say, XML Schema). If you are curious about STEP, one place to begin is my NASA STEP Testbed site ... http://step.nasa.gov/step_info.html ... some of the links are kinda old, but still good mostly. (I've been too busy lately to keep it updated as well as I should -- my NASA STEP Testbed project is developing a PDM system based on STEP, using Python and other open source technologies.) Of course, the STEP community is well aware that its complex information models and the Express language present a steep learning curve, so a lot of work has been done on developing an XML encoding for STEP data ... unfortunately, this has lead to 3 different XML bindings for STEP data, due to the flexibility of XML and the various types of applications that could use STEP data in different ways. Note that we (the Python community) could develop a probably more elegant mark-up language than XML for hierarchical data structures, "PyML" :^) ... based on recursive dictionary structures, which could have the advantage of being *executable* (and easier for us to write ;^). But you didn't hear that from me (of course it wasn't my idea ... lots of config files are written in PyML :^). I won't address the rest of Paul's message, but my own position on XML is pretty neutral (although it really bugs me when XML gets credit that is really owed to those who develop the software to deal with all the crazy things people try to do with it -- XML itself could have been developed by a 12 year old!). IMHO, XML is perfect for structured documents. Anything else is a maybe. However, XML is a fact of life, and we all have to deal with it, so bottom line: it really doesn't matter a [your expletive here] whether it's Good or Bad. -- Steve. http://misspiggy.gsfc.nasa.gov/people/waterbug.html _______________________________________________ Webware-discuss mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/webware-discuss
