Re: [xml-dev] XML spec and XSD

[Mukul Gandhi <gandhi.mukul@gmail.com>]

Hi Mike,
   At first thought, and even thinking a bit deeply I have quite a bit
of agreement to your arguments.

But I am trying to be very careful just now, before saying that "I
completely agree with you".

I still have a feeling in my mind, that "DTD validation" and "XSD
validation" both mean validating XML documents (i.e, conceptually DTD
and XSD validations are the same thing), but with different (XML)
Schema languages. I also think, the word validation in XML spec,
conceptually relates similarly to XSD or to any other XML validation
technology, as it means for DTDs.

You have said, "the word valid in the XML specification has a
different meaning from its use in the XSD specification". As I have
said above, unfortunately I am not entirely convinced by this
argumemnt :( But conceptually I agree with you, agreeing with your
argument that XML core specs, do not include the XSD spec.
Unfortunately it seems to me, that W3C XML activity sepcs are
structure in such a way, that XSD spec is separate from the XML core
specs (but the separation of XSD spec from XML core specs, look ok to
me), and that causes the confusion to readers when they read the word
"valid" in the XML spec, and that is referred to DTD only validation.

According to me, the XML spec (I am looking at the 5th edition spec,
of XML 1.0) clearly seems to convey, that XML validation is *only* a
DTD validation. And that is the main confusion to me. Because, in
present context XML validation can be done by other Schema language as
well like XSD, RelaxNG or Schematron.

I don't intend to have the core essence of XML spec changed. I even
like the description of entire DTD language in XML spec, and also
saying that DTD is a XML validation technology, in XML spec. But I
wish that if, a confusion regarding "XML validation" as mentioned in
the XML spec, which seems to be possible only with DTDs can be better
explained in the XML spec, that would be quite helpful, I believe.

Even if the word XSD cannot be mentioned explicitly in the XML spec, I
think a generic reference like "XML Schema" or perhaps "other XML
Schema languages" would look ok to me.

I feel though, that descriptions of DTDs in XML spec should definitely
be retained and being referred as a XML validation technology.

On Wed, Nov 11, 2009 at 2:41 PM, Michael Kay <mike@saxonica.com> wrote:
> When the XML specification uses the word "entity", it means something
> entirely different from what the UML spec means by "entity". That does not
> make the things it says about entities untrue: it just means that the reader
> has to be careful to remember what the meaning of the word is in the context
> of a particular specification. Similarly, the word "valid" in the XML
> specification has a different meaning from its use in the XSD specification.
> Also similarly, the word "processor" in the XML specification means
> something different from "processor" in the XSLT specification. Such
> differences are entirely legitimate. When discussing technology in a wider
> context, it's often wise to qualify your language to avoid misunderstanding,
> by talking of an "XML entity" or an "XML processor" or of documents being
> "DTD-valid". But it would be tedious to do that within a specification,
> where it's hard enough to avoid 6-tuple compound nouns at the best of times.



-- 
Regards,
Mukul Gandhi