> You're mixing apples and oranges. Schema validation (even DTD
> validation) is explicitly optional in XML. Furthermore you can
> process an invalid document. That is definitely not true of a
> malformed document. Failing to check well-formedness is not an option.
Agreed, well-formednes must be checked. But surely it doesn't need to be
checked every time a document is parsed (if it is unchanged). I think there
is definitely room for a parser that can emit SAX events (or something)
without bogging down in Wellformedness checks. For example, if a document is
received from a partner, wellformedness is checked, and then pushed into a
database text field for later processing, there is no need to recheck
wellformedness. In fact, when it is parsed again later, there is no need to
do a lot of things-- like check end tags-- if wellformedness is known a
priori the start tag can be pushed onto a stack, and popped when </ is read.
Then the "parser" can simply skip the length of the end tag. There are lots
of savings like this-- duplicate attribute checking for example can be
costly-- but would be unnecessary if wfness was assumed.
All the best,
Jeff Rafter
