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Re: 1.a: (David's Archform declaration gloss)



At 9:33 AM 2/3/97, Michael Sperberg-McQueen wrote:
>   <?XHL link=a,footnote>
>
This indicates that the Link XHL architectural form is the only one in use
in this document, and that it applies to the element types <a> and
<footnote>.

The DTD must declare the required attributes for that form, and the
processor _may_ validate the attribute specifications against the XHL
definition. An architectural form would specify:

    1. A set of attributes that should be present, and whether they are
optional or required (optional attributes need not be declared, as long as
not used).

    2. A content model to which every instance must corespond (and against
which the processor may validate the element's content model, for
compatibility).

    The processor _should_ (must?) apply appropriate link semantics to
those elements in context.


Of course, if you don't have a DTD, the attributes are still there in the
instance.

This method of doing archforms does not require #FIXED attributes to signal
an element with an archform, or indeed any architecture-signalling
attributes at all. We might prefer to continue imposing such a requirement
for compatibility with SGML practice, or we could simply allow it, on the
principle that anyone who needs the compatibility could ensure it
themselves.

The other suggestion:
<?XHL all?>
would activate all XHL architectural forms for this document, and would
apply them to elements with the same names (e.g. the "link" form, if it
exists, would apply to the <link> element type). In this example, I changed
the confusing keyword "on" to "all" for greater clarity that a shole set of
declarations is actually being made.

I just realized that this should be:

<?XHL 1.0 all?>

so that when XHL 2.0 adds 500 element types, we don't create name conflicts
in existing documents.

I thought we might make "all" the default, but then we would not have an
XHL version number -- unless we make XHL and XML version numbers track
exactly...

  -- David



I am not a number. I am an undefined character.
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