Re: [xml-dev] Is the set of languages expressible using XML asuperset of

[Michael Kay <mike@saxonica.com>]

The only thing left from Roger's original question is the title, which talks of "the set of languages expressible using XML". He didn't ask about the set of all instance documents, he asked about the set of languages, which can only refer to XML vocabularies defined in (say) a schema or DTD. And we know that (some) schema languages can tell you that a particular attribute is an integer or a date.

What they can't tell you, in a formal way that computers can understand, is that an attribute called date-of-birth is supposed to contain the date on which someone was born, but in some cases it might contain the date on which the birth was registered. That's what I mean when I say "semantics".

Michael Kay

Saxonica

On 29 Jan 2022, at 06:59, Mukul Gandhi <mukulg@softwarebytes.org> wrote:

On Sat, Jan 29, 2022 at 9:21 AM Rick Jelliffe <rjelliffe@allette.com.au> wrote:

OK, so show me in the "massive" XML standard (without resorting to any other layer or standard) how to say that some specific string (i.e an attribute value ir element contents) containing digits is a number, say a decimal number?

I think that, you're right. We cannot express data types like decimal using XML vanilla syntax. For that, I guess we'd need something like XML Schema capabilities.

 

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Regards,

Mukul Gandhi