Re: C.4 Undeclared entities? [CDATA #REQUIRED?]
At 2:25 AM 10/19/96, Harvey Bingham wrote:
>>So there is always a DTD. Now the question is: what does a parser do with
>>references to undeclared entities? There is no reason to do anything different
>>from what is done in SGML.
>An undeclared entity could be passed on to the application, and possibly
>retained as such when part of #PCDATA.
I think Harvey has this exactly right. Making this unbound entities visible
to the application, taken together with the synchrounous markup
restriction, means that parsing document fragments becomes trivially
similar to parsing a document without a DTD; the only difference is the
possiblity that the entity might not be a single element.
This lets us solve several problems at once, in a pretty clean general way.
And certainlty, at least for external entities, we will need to let an
application control when and whether they are resolved. Imagine a browser
where you couln't stop it from going out to the net for embedded files.
>>As for declaring entities automatically, I assume that means there will be a
>>piece of public text containing the "automatic" declarations that is
>>to be referenced by all DTDs (including the implied one). Or, to put it
>>way, all DTDs are partial; the "automatic" entity declarations are the other
>That "automatic" set of entity declarations is open-ended, effectively any
>apparent entity should be in it.
Not true. Some names will be predeclared to have fixed meanings, rather
than representing "free variables." Any entity currently in the HTML
declaration should be automatically declared with its current value. We may
also need entities for hexadecimal character codes, if Gavin's function
character proposal does not fly.
These are essentially hard requirements for acceptance. People get these
"features" for free to day, telling them that they have to add declarations
for the obvious and useful will, fail the "Stooopid" test.
The user-hostility of requiring a new convention for character
references that is different form the stadard reference material, and
requires a numberical base conversion ought to be evident on the face of
RE delenda est.
David Durand firstname.lastname@example.org \ david@dynamicDiagrams.com
Boston University Computer Science \ Sr. Analyst
http://www.cs.bu.edu/students/grads/dgd/ \ Dynamic Diagrams
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