Re: [xsl] Re: What is the Venn diagram for XPath, XQuery, andXQuery Update?

["Martin Honnen martin.honnen@xxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>]

On 2/1/2023 9:05 PM, Roger L Costello costello@xxxxxxxxx wrote:
> Thanks Martin for the pointer to the Saxon web page on XQuery Update. That
web page says this:
> ---------------------------------------------
>
> Saxon implements XQuery Update Facility 1.0, which reached Recommendation
status on 17 March 2011. All features, including optional features, are
implemented.
> The XQuery Update specification defines a number of extensions to the XQuery
1.0 grammar. Saxon implements these as extensions to the XQuery 3.1 grammar.
> ---------------------------------------------
>
> Huh? I'm confused.  What is that saying? Is it saying:
>
>
>
> (a) Saxon implements XQuery Update 1.0 which is a superset of XQuery 1.0
which is a superset of XPath 1.0
> (b) Saxon implements XQuery Update 1.0 which is a superset of XQuery 3.1
which is a superset of XPath 3.1
> (c) Something else - what?

I think you are on the wrong way with your subset/superset idea or
terminology, I did already post a simple XPath expression (a string
literal with an ampersand) that doesn't work as an XQuery expression.


As for XQuery Update being a superset of some XQuery, I don't think so,
it has extensions in the form of new expressions but also restrictions
on how expressions can be composed, once you use XQuery Update your are
bound to ensure your expressions/programs follow the rules for XQuery
update. You can't freely and arbitrarily mix updating and non-updating
expressions, for instance, at least as far as I understand it.