- From: didier ph martin <dmartin@cedep.com>
- Date: Wed, 5 Mar 1997 16:17:53 -0500
- To: <www-talk@w3.org>
During the past months we have worked on an implementation of the MCF language (ref: http://mcf.research.apple.com/hs/mcf.html). However, instead of using URLs identifier for units we used URNs. We looked at several draft: PATH URL: draft-ietf-uri-urn-path-01.txt PURL Handle We found in these projects very interesting things, but we got a major constraint. Independently of turf and religion wars (which remind me of some dark ages) we have market constraints. Concretely, this means that to implement name spaces (at the base of URN), we have to deal with Novell NDS, Microsoft Active Directory, DNS on some systems, the desktop name space and so on... Even if we grabbed ideas from these previously mentioned projects, we had, after more thought, to design a URN protocol that would take into account this reality. What is the procedure to propose a new protocol? At the same time, we want to propose a modified MCF language proposal as well as a new URN protocol. Thanx for your help. To get some immediate feedback from people that subscribe to this list. Here is some info about the URN protocol. We call it "tns" for transportable name service. The spirit behind this is to create a Uniform Resource Name naming convention for name spaces. It doesn't tell where are the objects, it just position them into a hierarchical name space that you can represent as a tree. Name servers implementing these name spaces have to keep a record of attributes associated to this name. As you already know there two kinds of name services (maybe more?) you give the name path and you get a record or a field associated to this name path. The other one being that you give an attribute and you receive an object associated to that. This is the white vs yellow pages thing. The syntax for tns is as follow: tns://<name server>:<name path> where <name server> could be something like dns:w3.org (the access protocol for this name server is DNS) or nds:w3.org if Novell directory service is used. If a local workstation support namesake conventions: the wks protocol is then used. This means that we are using a local name server resident on the workstation. <name path> is a set of names separated by "/" like for example "NameConvention/URN/OurProposal". As an example: "tns://dns:w3.org/ NameConvention/URN/OurProposal" would result on a query to a name server located at W3.org and the path "NameConvention/URN/OurProposal" as a hierarchy of names. the result can the be the associated URN's record. Used in a different context, a URN can be useful as well. The other context we tested is the MCF context. In MCF, each object is defined as a unit with an associated set of attributes. The syntax described in the document (http://mcf.research.apple.com/hs/mcf.html this is a real URL) states that attributes (and a unit may be seen as an attribute) has values associated to them. The syntax (only an idea not he complete specs) is as follow: <slot>:"<value>" (this only mention single value attributes, but he language can support multi valued attributes or slots) So if we use the tns protocol to uniquely identify an object, we then have: unit:"tns://wks:Desktop/MyWork/NameConvention/URN/OurProposal/" (this means that this object is part of a local workstation name space) location:"http://w3.org/specs.htm" (this is the location - be cautious, these are not real URLs or URNs that are only examples) subject: "new proposals" author:"Didier PH Martin" (the unit may have any number of attributes. Each interpreter just pick what's useful). So the "tns" protocol can be used in two (probably more) different contexts: to reach a name server particular name's record. to uniquely identify a unit within a MCF document To the original specs proposed by R.V Guha, we suggest a modification to the value syntax. To each attribute is associated a value. This value (or these values) are enclosed by a set of "". To unify the MCF language with RFC 822 we propose that attributes' values can be delimited by "" and by a space and a CTRLF. This way, a e-mail header would be treated by a MCF interpreter. Therefore a mail header could be treated as meta content (isn't that anyway what it is?) example: to: www-talk@w3.org subject: table of content tocOf: the proposal unit: tns://tns://wks:Desktop/MyWork/NameConvention/URN/OurProposal/ location: http://w3.org/specs.htm author: Didier PH Martin etc... If you want to give some feed backs you can in this list if it is appropriate (I don't know anymore what's appropriate and not we I get invaded by religion Microsoft vs Non-Microsoft war messages). or you can send me e-mail to dmartin@cedep.com Didier PH Martin Talva inc.
Received on Wednesday, 5 March 1997 16:28:24 UTC