> >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).
>
> How do you know no other process or person has modified the field in
> the mean time?
>
Why not define a standardized checksum, that can be included in the XML
declaration, e.g.
<?xml version="1.2" checksum="08bd37f1"?>
with the rules:
(a) nothing other than a parser that checks well-formedness may generate a
checksum
(b) at user option, a parser may skip some or all well-formedness checks if
a checksum is present and correct?
A user who doesn't trust the originator of the XML should still check for
well-formedness.
I personally don't think that XML parsing is that time-critical to most
applications, but I can imagine that there are applications where avoiding
the cost of repeatedly checking (for example) that every name is made up of
valid characters would be beneficial.
Michael Kay
