xml-dev - Re: What is PI data exactly?

["Michael Kay" <M.H.Kay@eng.icl.co.uk>]

From: John Cowan >
>> So if a PI has a target and data, what is the data in the following
scenarios?
>>
>> <?Foo?>
>> <?Foo     ?>
>>
>> Is the first null data and the second a string of spaces?
>
>The first case is definitely null data.  Production 16 says that
>the optional data is prefixed by one or more whitespace characters
>which are not part of it

Are you reading the same spec as me? My version of production 16 doesn't
mention "data" at all; all it says is that if there are characters after the
PITarget, the first one must be white space. As it doesn't mention data, I
don't see how it can tell me whether or not the white space is part of the
data. Actually I think the notion of "data" in a PI is a SAX notion, not an
XML one.

Meta-comment: we're suddenly getting a spate of comments that point to
little inconsistencies or ambiguities in the spec, reflecting the fact that
it is written very informally. I think the problems are particularly acute
when the spec tries to talk about the actions of "XML processors" or
"applications" because these notions are very fuzzy. There's good scope for
a researcher to add value by producing a formal spec of XML+SAX which tells
me definitively which documents are well-formed, which are valid, and what
the SAX calls will be for any given document (or non-document). Anyone who
is spending time writing yet another XML parser would be adding a lot more
value to the community if they spent their time on producing a formal
specification instead.

Mike Kay


xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev@ic.ac.uk
Archived as: http://www.lists.ic.ac.uk/hypermail/xml-dev/
To (un)subscribe, mailto:majordomo@ic.ac.uk the following message;
(un)subscribe xml-dev
To subscribe to the digests, mailto:majordomo@ic.ac.uk the following message;
subscribe xml-dev-digest
List coordinator, Henry Rzepa (mailto:rzepa@ic.ac.uk)