Re: Why self describing data formats:

2007-06-25 Thread Steven M. Bellovin
On Fri, 01 Jun 2007 20:59:55 +1000 James A. Donald [EMAIL PROTECTED] wrote: Many protocols use some form of self describing data format, for example ASN.1, XML, S expressions, and bencoding. Why? Presumably both ends of the conversation have negotiated what protocol version they are

Re: Why self describing data formats:

2007-06-23 Thread James A. Donald
James A. Donald: In the case of XML, yes there is a parsing engine, and if the structure of the DTD reflects the structure of the algorithm, then indeed it makes things much easier. But usually the committee have not thought about the algorithm, or have unresolved disagreements about

Re: Why self describing data formats:

2007-06-23 Thread Nicolas Williams
On Mon, Jun 11, 2007 at 11:28:37AM -0400, Richard Salz wrote: Many protocols use some form of self describing data format, for example ASN.1, XML, S expressions, and bencoding. I'm not sure what you're getting at. All XML and S expressions really get you is that you know how to skip past

Re: Why self describing data formats:

2007-06-21 Thread James A. Donald
James A. Donald wrote: Many protocols use some form of self describing data format, for example ASN.1, XML, S expressions, and bencoding. Why? Presumably both ends of the conversation have negotiated what protocol version they are using (and if they have not, you have big problems) and when

RE: Why self describing data formats:

2007-06-21 Thread Bowness, Piers
On Friday, June 01, 2007 7:00 AM James A. Donald wrote: Many protocols use some form of self describing data format, for example ASN.1, XML, S expressions, and bencoding. Why? Presumably both ends of the conversation have negotiated what protocol version they are using (and if they

Re: Why self describing data formats:

2007-06-21 Thread Leichter, Jerry
| Many protocols use some form of self describing data format, for | example ASN.1, XML, S expressions, and bencoding. | | Why? | | Presumably both ends of the conversation have negotiated what protocol | version they are using (and if they have not, you have big problems) | and when they

Re: Why self describing data formats:

2007-06-21 Thread Richard Salz
Many protocols use some form of self describing data format, for example ASN.1, XML, S expressions, and bencoding. I'm not sure what you're getting at. All XML and S expressions really get you is that you know how to skip past something you don't understand. This is also true for many (XER,

Re: Why self describing data formats:

2007-06-21 Thread Will Morton
James A. Donald wrote: snip In the case of XML, yes there is a parsing engine, and if the structure of the DTD reflects the structure of the algorithm, then indeed it makes things much easier. But usually the committee have not thought about the algorithm, or have unresolved disagreements

Re: Why self describing data formats:

2007-06-21 Thread Nicolas Williams
On Fri, Jun 01, 2007 at 08:59:55PM +1000, James A. Donald wrote: Many protocols use some form of self describing data format, for example ASN.1, XML, S expressions, and bencoding. ASN.1 is not an encoding, and not all its encodings are self-describing. Specifically, PER is a compact encoding

Re: Why self describing data formats:

2007-06-21 Thread Nicolas Williams
But the main motivation (imho) is that it's trendy. And once anyone proposes a heavyweight standard encoding, anyone who opposes it is labeled a Luddite. Maybe. But there's quite a lot to be said for standards which lead to widespread availability of tools implementing them, both, open source

Re: Why self describing data formats:

2007-06-21 Thread Nicolas Williams
On Mon, Jun 11, 2007 at 09:28:02AM -0400, Bowness, Piers wrote: But what is does help is allowing a protocol to be expanded and enhanced while maintaining backward compatibility for both client and server. Nonsense. ASN.1's PER encoding does not prevent extensibility.

Re: Why self describing data formats:

2007-06-11 Thread Anne Lynn Wheeler
James A. Donald wrote: Many protocols use some form of self describing data format, for example ASN.1, XML, S expressions, and bencoding. Why? gml (precursor to sgml, html, xml, etc) http://www.garlic.com/~lynn/subtopic.html#sgml was invented at the science center in 1969

Re: Why self describing data formats:

2007-06-11 Thread Anne Lynn Wheeler
re: http://www.garlic.com/~lynn/aadsm27.htm#24 Why self describing data formats: for other archaeological trivia ... later i transferred from the science center to SJR and got to do some of the work on the original relational/sql implementation, System/R. a few years later, the L in GML also