[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] Proposal for src files
I am very pleased to see the namespace draft being discussed here because I think it has important bearing on implementation. I have been privileged to be on the XML-SIG and - without revealing confidentiality - there was a lot of closely argued discussion and this is clearly a tough problem [?tougher than some people initially expected?]. The clarifications given here have been spot-on - the provision is primarily syntactic, providing the identification of components of a name, and the namespace(s) referred to. The distinction between identification of the namespace (ns) and the details of it (src) is very welcome. Specific comment: The following example has been used in the namespaces draft: <Item T.Heat:Temp='5500'/> and suggests some special role for the '.' in the attribute name. There appears to be a widespread practice among SGML authors of using '.' as a means of indicating structure in names. There is no syntactic significance for the '.' in XML and I very much hope that there is no 'implied semantics' given to it. I believe the only reason for it is human readability, and it could be seen as misleading in the current discussion. As far as namespaces are concerned, processing software should treat T.Temp: and Plugh: on equal terms. Clearly anyone wishing to implement namespaces *now* has a problem in that there are no agreed semantics. Since namespaces are (in large part) about interoperability between different document designers (who are probably not in communication) it seems likely that uncoordinated approaches could give rise to confusion. By concern - and I'm sure it's shared by many - is that we get embroiled in 'namespace soup'. What the proposal *does* give us is the ability to find out *who* is responsible for a given tag. In principle, therefore, we can refer to that tagger's description of its semantics. The problem is the lack of standards for semantics (e.g. we don't know what is in the src file). It is clear that some people (e.g. RDF) will develop a de facto approach to the semantics of namespaces. I suspect that in the first instance most of these will lead to documents which cannot be validated against a DTD under XML 1.0 (excepting the ANY content spec). This is my own position - for reasons mentioned on XML-L, CML documents are not constructed to be validatable. Although having experimented with namespaces for some time and found them extremely useful, I don't have any simple answers to the problem. If there are any steps that we can take on XML-DEV to solve *part* of the problem, that could be very useful. Are there any operations which are common to all namespace processing? Is it useful to codify the de facto solutions that people provide so that - at least - we could identify the approach that an author uses? For those of us developing 'src' files is there a useful way of identifying the contents? possibly even standardising them? My own contribution would be to try the following (not to the exclusion of others): <AXIOM> There seem to be a significant number of people who expect an src document to be in XML. </AXIOM> I belong to them. <AXIOM> There are a lot of people who wish the schema to represent the validatory power of an XML DTD. Many wish it *to* be a DTD. </AXIOM> <PROPOSAL> Is it possible to combine these two so that we express a DTD in a standard XML notation? Many of us do this already, but I suspect that our tagset and syntax vary. If we could agree on this - and I don't see this as technically difficult - we could help both communities. Those who wished more power than a DTD can provide can extend it with further elementTypes (a la XML-data). Those who wish to use the DTD elementTypes alone can filter them out very easily and - if required - transform them to DTD syntax. Clearly this is only one of many things that could reside in an src file, so some means of identifying it would be required. We should, of course, create our own namespace for the elements - mapped to xml.org :-) </PROPOSAL> Given the achievement of creating SAX on this list, we can certainly solve this one if we wish to. P. Peter Murray-Rust, Director Virtual School of Molecular Sciences, domestic net connection VSMS http://www.nottingham.ac.uk/vsms, Virtual Hyperglossary http://www.venus.co.uk/vhg xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev@i... Archived as: http://www.lists.ic.ac.uk/hypermail/xml-dev/ To (un)subscribe, mailto:majordomo@i... the following message; (un)subscribe xml-dev To subscribe to the digests, mailto:majordomo@i... the following message; subscribe xml-dev-digest List coordinator, Henry Rzepa (mailto:rzepa@i...)
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