I probably should point out that I would likely only need a fairly small subset of XML to do useful things. Pre-defined tags (i.e. known a priori by both "client" and "server") that could be very short (by convention) and probably custom set of attributes per whatever the application was. Thing is, the "easiest" way to implement parsers for Regular Grammars (such as what this would end up being) is to use recursion. (Now, some folks might feel more comfortable with other non-recursive methods, but that's *my* approach of choice). Recursion gobbles stack space, and there's the rub. I haven't had the chance to look at the 17xxx or 18xxx architectures yet; seems they might offer a better capability set for this sort of thing. The string manipulation stuff isn't my concern: once you have a couple of basic string methods you can do a lot (including parsers); "compare", "substring", "find character", "copy", etc. methods, and a decent hashtable are the basics. The data address space is probably the biggest issue, aside from stack. External RAM via Port access (not serial) might be fast enough to make this work; but then it wouldn't really be "generic". As for my usage of XML... for example, I'm currently working on a Process Controller device that can be (RS232) programmed from the PC. I've got a command protocol that the PC side uses to create an object hierarchy in the PIC device (I2C EEPROM). If I had XML reader on the PIC side, what I would do is have the PC generate XML description of this data, and just send it to the PIC. It's the same end result, but the difference is a data-driven vs. command-driven approach, which (in theory anyway) would allow a more robust object oriented implementation. Jim ----- Original Message ----- From: "Wesley Moore" To: Sent: Wednesday, August 13, 2003 6:56 PM Subject: Re: [PIC:] XML parsing on PIC? > I think a PIC based XML parser would certainly be a very daunting task. > String manipulation is not one of the things I consider a PIC does well and > then there's the memory and stack issues. I think you would proabably be better > of trying this with a chip that has a more flexible RAM configuration and > I think a stack would also be useful. Out of interest, what were you thinking > of doing with XML? > > Wesley > > On Wed, Aug 13, 2003 at 08:04:34AM -0700, Jim Tellier wrote: > > The earlier post re: "command string interpreter / parser" reminded me that > > I've wanted to dig into this a bit.. anyone ever written a PIC/mid-range > > parser for XML? Due to memory issues and stack limitations, I'm thinking > > this might be a daunting task...but sure would be useful! > > ...just thinkin' out loud! :^) > > Jim > > -- > Wesley Moore http://wmoore.freeshell.org/ > RMIT - BEng (Comp Sys Eng)/BApp.Sc. (Comp Sci) 5th (And Final!) Year > SDF Public Access UNIX System http://sdf.lonestar.org/ > > -- > http://www.piclist.com#nomail Going offline? Don't AutoReply us! > email listserv@mitvma.mit.edu with SET PICList DIGEST in the body -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu