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This from the man who gave us the InfoSet.
Tell me, please, what the data model is for this. Because my mental view
of it looks something like a Klein bottle.
Michael Kay
> -----Original Message-----
> From: Richard Tobin [mailto:richard@cogsci.ed.ac.uk]
> Sent: 21 October 2003 15:14
> To: xml-dev@lists.xml.org
> Subject: [xml-dev] Alternative "character entity" proposal
>
>
> This is a proposal for a new mechanism for declaring internal
> entities, requiring a new version of XML.
>
> [I am not proposing this because I think it's a good idea - I
> can't see a good solution at all - but because it's an
> obvious approach that several people have talked to me about
> at W3C meetings and which has not been discussed in the
> recent threads on the subject. Henry Thompson proposed a
> similar mechanism a few years ago.]
>
> Since XML 1.0, replacements have been invented for most
> aspects of DTDs:
>
> - content restriction and typing is provided by XML Schemas,
> Relax NG,
> Schematron etc
>
> - something similar to external entity inclusion is provided
> by XInclude
>
> - ID-ness is being addressed by the current work on xml:id
>
> In each case the replacement uses (or can use) XML instance
> syntax rather than DTD syntax.
>
> The obvious missing item from the list is internal entities,
> especially in their use as names for characters.
>
> In theory, XInclude can replace internal entities. The href
> in an xinclude element can refer to a fragment of the same
> document. But this is hardly convenient: it is very verbose,
> and you have to find somewhere to put the text itself.
> XInclude works well for merging small documents into a large
> document, but not so well for defining frequently-used short
> sequences of characters.
>
> The proposal is to continue to use the existing entity
> reference syntax, while providing a new way to declare
> entities. The declarations would use XML instance syntax,
> and be scoped to allow multi-vocabulary documents where the
> vocabularies have their own entity sets - in particular, it
> is not necessary to change the prolog or higher-level
> elements to include a fragment which uses its own entity set.
>
> The syntax for declaring a single entity is an attribute of the
> form:
>
> xmlent:eacute="é"
>
> Within the scope of the element with that attribute, é
> will refer to the e-acute character.
>
> The replacement text is not restricted to a single character:
>
> xmlent:author="Richard Tobin"
>
> A file of entity declarations can be specified by an attribute of the
> form:
>
> xmlentfile="http://example.org/ents";
>
> or more than one file:
>
> xmlentfile="http://example.org/ents1 http://example.org/ents2";
>
> These files must contain a single element, whose name is
> arbitrary, and that element may have xmlent:* and xmlentfile
> attributes. All the entities declared in the file (and
> recursively) are in scope within the element with the
> xmlentfile attribute.
>
> Within the scope of such declarations, references to the
> entities are both well-formed and valid. This implies a new
> XML version number.
>
> There are many variations possible: the single inline
> declaration could be removed; the file syntax could use
> elements, the entity names could be namespaced, and so on.
> The key point is to have a scoped mechanism for declaring
> internal entities using xml-instance syntax.
>
> -- Richard
>
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