Re: [xml-dev] What does an empty element denote?

[Michael Kay <mike@saxonica.com>]

and in the world of schema languages, that alphabet is typically the set of permitted element names.

[mukul] Is it not that, alphabet in the world of schema languages (XSD in particular) consists of the set of permitted element names and also optionally attribute names and XML namespace names? But I think as what made me felt from Mike's point, that XML documents always ought to have elements, but they can have attributes and XML namespaces optionally.

In DTDs and in XSD (I think also in RelaxNG, correct me if I’m wrong), a grammar for a content model is defined in terms of permitted sequences or choices of element names (where an element name in DTD is a lexical QName, and in XSD is an expanded QName). Attributes don’t come into it.

In my Balisage paper on FtanML a couple of years ago I explored the idea of using a grammar where the alphabet consists of types, so the grammar could allow <p class=“table”> and disallow <p class=“figure”>.

Michael Kay

Saxonica