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Re: RE : Question on Adding undeclared productions

From: Kevin Braun <kbraun@obj-sys.com>
Date: Mon, 11 Nov 2013 11:17:43 -0500
Message-ID: <52810327.9070500@obj-sys.com>
To: FABLET Youenn <Youenn.Fablet@crf.canon.fr>
CC: "public-exi-comments@w3.org" <public-exi-comments@w3.org>
Hi Youenn,

Thanks for the reply.  Yes, I see that a similar thing can happen for CH 
events and also for SE events.  I had originally thought that when an 
event had more than one event code, they would necessarily be 
distinguishable by the presence or lack of the [untyped value] 
designation, but that is not the case.

So, as an example, it is possible to have a non-terminal with 
productions like:
     ElemX : AT(*) ElemX    a
     ElemX : AT(*) ElemX    b.c
     ElemX : AT(*) [untyped value] ElemX   b.(c+1).d

where the first two productions are completely interchangeable; whenever 
one could be used, the other could just as well be used.  I don't see 
anything that prevents an implementation from actually using the longer 
event code (though I can't imagine why they'd want to), so I suppose 
decode implementations are obliged to be ready to handle both the longer 
and the shorter event codes.

I personally find this is a little surprising, so I think it would not 
be a bad idea to note the possibility of interchangeable/redundant event 
codes in the text.  You might do so even in 8.5.4.4 as part of the 
introductory/overview text.

Thanks & Regards,
Kevin


On 11/10/2013 9:40 PM, FABLET Youenn wrote:
> Hi Kevin,
>
> The production Element (i,j) : AT(*) Element (i,j) with event code n.m, is always added to any schema-informed grammar that may have to represent attributes, even though there is  already a first-level  AT(*) production.
> This is similar to CH productions that may occur as first-level and second level-productions of the same grammar.
> This was deemed acceptable by the working group as a tradeoff between implementation complexity and compactness.
> Please let us know if further clarification would be needed in section 8.5.4.4.1 text.
>
> Regards,
>       Youenn
>
> ________________________________________
> De : Kevin Braun [kbraun@obj-sys.com]
> Date d'envoi : jeudi 31 octobre 2013 21:50
>  : public-exi-comments@w3.org
> Objet : Question on Adding undeclared productions
>
> Hi folks,
>
> In 8.5.4.4.1, where the text calls for adding a production:
>       Element (i,j) : AT(*) Element (i,j)
> with event code n.m,
>
> I assume this particular addition should only be done when there is not
> already a production for AT(*) (such as when there was an {attribute
> wildcard} for the type)?  I think it would be good to clarify this in
> the text.
>
> Regards,
> Kevin
Received on Monday, 11 November 2013 16:18:04 UTC

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