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Re: [ISSUE-51] Formulae wrappers (2/2: required or optional)

From: Jos de Bruijn <debruijn@inf.unibz.it>
Date: Tue, 29 Apr 2008 13:59:28 +0200
Message-ID: <48170DA0.2080607@inf.unibz.it>
To: Christian de Sainte Marie <csma@ilog.fr>
CC: RIF WG <public-rif-wg@w3.org>
> 
> Beside the question of enabling different dialects to distinguish 
> different kinds of groups of FORMUALE without bloating FLD (see [1]), 
> and still leaving aside the orthogonal issue of where to hang metadata, 
> there might be another issue in the Group/Rule discussion that I did not 
> see explicited in emails nor telecon mminutes (but I missed some 
> telecons recently).
> 
> In a solution like the one in the first part of this message [1] 
> (similar to the one Chris proposed [2]), RULE formulae can be wrapped 
> directly in a Group (without each being wrapped in a Rule WRAPPER):
> 
>   Document       ::= 'Document' '(' Group? ')' /* leaving meta etc out
>   WRAPPER        ::= Group | Rule
>   Group         ::= 'Group' '(' (RULE | WRAPPER)* ')'
>   Rule         ::= 'Rule' '(' RULE ')'
> 
> Is that a issue for the people who want a specific Rule wrapper or isn't 
> it one?

It is not an issue for me.  The Rule wrapper can be optional; one would 
only use it if one wants to assign an identifier or attach metadata to a 
rule.

Best, Jos

> 
> As I mentionned already, a problem I can see with that solution is that 
> there are many different ways to serialise the same set of RULE formulae 
> (e.g. as a Group of RULEs or as a Group of Rules). Or isn't that a problem?
> 
> If it is, a solution could be to disallow Groups to wrap RULEs directly:
> 
>   Document       ::= 'Document' '(' Group? ')' /* leaving meta etc out
>   WRAPPER        ::= Group | Rule
>   Group         ::= 'Group' '(' WRAPPER* ')'
>   Rule         ::= 'Rule' '(' RULE ')'
> 
> But that would make wrapping each RULE in a Rule mandatory, instead of 
> optional: or is that desirable to some people in the group?
> 
> Another question regards the Document production: would it be a problem 
> to allow a Document to contain several Groups at the same level? If not, 
> we could have:
> 
>   Document    ::= 'Document' '(' WRAPPER* ')'
> 
> instead (same in FLD),which would allow a document to contain a set of 
> Rule WRAPPERs directly, where an additional Group is not needed.
> 
> Opinions? Comments?
> 
> Christian
> 
> [1] http://lists.w3.org/Archives/Public/public-rif-wg/2008Apr/0186.html
> [2] http://lists.w3.org/Archives/Public/public-rif-wg/2008Apr/0148.html
> 
> 

-- 
Jos de Bruijn            debruijn@inf.unibz.it
+390471016224         http://www.debruijn.net/
----------------------------------------------
An expert is a person who has made all the
mistakes that can be made in a very narrow
field.
   - Niels Bohr


Received on Tuesday, 29 April 2008 11:59:46 GMT

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