Cart
[Home] [By Thread] [By Date] [Recent Entries]
Tim Bray scripsit:
> I have not suggested a solution for
> how to solve the *hard* problem, namely how to go about making a
> compound DTD, and would like to hear input on that. -Tim
As far as I can see, such a thing is not possible even in principle,
except through the promiscuous use of ANY content models. Given
that you want to combine two separate DTDs, {A} and {B}, with or without
prefixes, initially only {A} elements will be permissible content
for other {A} elements, and likewise for {B} elements. So whatever
the root element of a document may be will dictate what elements
are to be used within it.
In order to make this otherwise, someone must decide exactly which
elements from {A} can have {B} content and vice versa. That is
inherently beyond the ability of an algorithmic process unless it
has detailed semantic information on the elements, *far* beyond
what any DTD provides.
IBTWSH uses a trick, a parameter entity that a containing DTD may
define in order to specify elements from the containing DTD that
can appear within IBTWSH elements. But average DTDs don't have
such a mechanism, and it may not even be possible. (Nonetheless,
this trick suggests how DCD/XML-Data elements with "open" content
might be translated back into DTD element declarations.
--
John Cowan http://www.ccil.org/~cowan cowan@c...
You tollerday donsk? N. You tolkatiff scowegian? Nn.
You spigotty anglease? Nnn. You phonio saxo? Nnnn.
Clear all so! 'Tis a Jute.... (Finnegans Wake 16.5)
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...)
|
