Re: [xml-dev] The meaning of the "string" datatype?

[rjelliffe@allette.com.au]

C. M. Sperberg-McQueen wrote

> In XSD, date is not a restriction of string for much the same reason
> that in SQL, timestamp is not a subtype of VARCHAR, and in most
> programming languages, date objects or structs are not restrictions
> of char* arrays.

So you are saying that XSD's datatyping is based on the physical storage
constraints of non-XML technology, and nothing to do with the data
itself...

(And, no they were programmers.)

> On 15 Apr 2009, at 07:20 , Rick Jelliffe wrote:

>> The original XML Schemas datatype hierarchy was not designed with
>> document refinement in mind (i.e. marking up the document, passing
>> it as text through several different XML stages):
>
> That seems odd to me; it was certainly on the minds of some in the WG.
> Perhaps not on yours.

Then why, when the WG was reconstructing the functionality of parameter
entities, was there no reconstruction of IGNORE market sections?  (I was
not there at that time, so it is genuinely a question I don't know the
answer to.)

Does the new type switching proposed for XSD 1.1 pretty much reconstruct
IGNORE?

> But then I think it unwise to assume that processing a document through
> stages of a workflow will invariably result in restriction, or that the
> input and output of a transformation will always need to be described
> by the same schema.  YMMV, of course.

Certainly. So why isn't it equally unwise to assume that the output will
never be a restriction, nor that gathering into the same schema may not be
appropriate? (And I wrote 'refinement' there, not 'restriction.')


Cheers
Rick Jelliffe