Cart
[Home] [By Thread] [By Date] [Recent Entries]
From: Tim Bray <tbray@t...> > Meaning is only conveyed by > > (a) running code, or > (b) human-readable prose. > >To generate (a), you have to have (b) first. I would go further than this, and say that if a) does not allow retrieval of b), the system is not suitable for portions of a document production chain in which human intervention is required. So, not only direct documentation of the schema, but the schema should also provide a minimal level of diagnostic information. The systems THETIS and Schematron take the approach that a) and b) should to a great extent be coupled. In Schematron, machine-processable tests are attributes on text elements which state the assertion that is being made. I think there is a fundamental unresolved issue that there are lot of situations in which we can use various kinds of schema validation information: creating systems & tools, creating documents, validating documents, giving error messages, giving diagnostics, triggering defaulting behaviour, being used to allow logical combination of schema, and so on. To support these adequately, I believe a general-purpose schema language has to not only tightly integrate human-readable components, but also provide clear machine-processable enumerations of each possible error (& categorizing it against som controlled vocabulary) in a way that allows schema-processors to have a standard API that can be used to create validators, editors, etc. For an example of such an approach, see proposal http://www.ascc.net/xml/en/utf-8/error.html Rick Jelliffe 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/ and on CD-ROM/ISBN 981-02-3594-1 To unsubscribe, mailto:majordomo@i... the following message; unsubscribe xml-dev To subscribe to the digests, mailto:majordomo@i... the following message; subscribe xml-dev-digest List coordinator, Henry Rzepa (mailto:rzepa@i...)
|
