Re: Static flagger belongs in static context

Michael Kay wrote:

>>"2.6.6.1 XQuery Flagger" says: "If the XQuery Flagger is 
>>enabled, a static error [err:XQ0015] is raised if the query 
>>contains a must-understand extension." This implies that the 
>>XQuery Flagger must be available in the static context.
>>
>>    
>>
>
>I personally think the XQuery Flagger is unenforceable and therefore
>should be removed.
>
>We cannot stop someone shipping a product that supports two languages,
>one of which is XQuery and the other is NotXQuery. Such a product can
>claim conformance. The fact that the language supported by NotXQuery is
>actually XQuery plus extensions, with no flagger, cannot alter the fact
>that the product as a whole is conformant. The XQuery specification
>cannot impose any constraints on the behavior of a NotXQuery processor.
>  
>
I think that the flagger solves an important problem for the language - 
it gives vendors a way to extend the language without changing the 
grammar of XQuery per se, and using a syntax that is obviously an 
extension. Some of these extensions may make it into future versions of 
XQuery as part of the XQuery BNF.

It also clearly signals to vendors that they should not monkey with the 
grammar of XQuery per se, and that the Working Group does not intend to 
grant precedent to proprietary extensions to XQuery. If you want to make 
a proprietary extension, use the mechanisms we have provided.

Jonathan

Received on Tuesday, 10 February 2004 19:04:05 UTC