Re: [XPath] Incompatibilities with XPath 1.0

I agree with Mike - if I have an existing XSLT 1.0 stylesheet, and I 
want to know what I have to make it work with XSLT 2.0, this list of 
incompatibilities tells me precisely what to watch out for. A global 
statement that "these are two different languages" does not tell me what 
I need to change. And of course it would be good to have the languages 
be the same, but there have been specific reasons for each change.

I'm classifying this as substantive, but I am not sure if you have 
specific requests for greater compatibility - if so, listing them would 
be helpful.

Jonathan

Michael Kay wrote:

>Thanks for the comment (this is a personal response).
>
>We've obviously done a lot of work to try and keep the list of
>incompatibilities to an absolute minimum. One reason that the list is
>long is that we've tried to document them meticulously, regardless how
>minor they are. We could have a debate about each one individually (for
>example, whether it is acceptable to change the string representation of
>very small numbers from "0.00000000001" to "1E-11") but it's not easy to
>respond to a general comment that says there are too many items in the
>list.
>
>We could try to put some of these under the control of the backwards
>compatibility switch.
>
>I don't think a switch that says "ignore everything you read in this
>spec and do what the XPath 1.0 spec says instead" would be useful.
>Implementations may provide such a switch, but that's a switch as to
>whether to run an XPath 1.0 processor or an XPath 2.0 processor; if they
>select an XPath 1.0 processor then the XPath 2.0 specification doesn't
>come into play, so there is nothing useful we can say about it.
>
>Michael Kay
>
>  
>
>>-----Original Message-----
>>From: public-qt-comments-request@w3.org 
>>[mailto:public-qt-comments-request@w3.org] On Behalf Of Martin Duerst
>>Sent: 13 February 2004 17:17
>>To: public-qt-comments@w3.org
>>Subject: [XPath] Incompatibilities with XPath 1.0
>>
>>
>>
>>I'm quite frightened by the long list of incompatibilities 
>>(even despite a special compatibility switch) between XPath 
>>1.0 and XPath 2.0. Each of these items seems to be small, but 
>>overall, this has a large potential for confusion, subtle 
>>errors, and so on. Not a big problem for a spec, but a 
>>potential nightmare for deployment.
>>
>>My guess is that to avoid this, implementations will probably 
>>implement both XPath 1.0 and XPath 2.0. If that's the case, 
>>it would be easier to make the compatibility switch switch 
>>all features, rather than just part of them. Bringing XPath 
>>1.0 and 2.0 closer together would be even better.
>>
>>
>>Regards,   Martin.
>>
>>    
>>
>
>  
>

Received on Monday, 16 February 2004 19:06:58 UTC