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Re: New version of FLD

From: Dave Reynolds <der@hplb.hpl.hp.com>
Date: Mon, 06 Apr 2009 09:25:16 +0100
Message-ID: <49D9BC6C.2030506@hplb.hpl.hp.com>
To: kifer@cs.sunysb.edu
CC: RIF WG Public list <public-rif-wg@w3.org>
Michael Kifer wrote:
> 
> On Mon, 06 Apr 2009 08:28:44 +0100
> Dave Reynolds <der@hplb.hpl.hp.com> wrote:
> 
>> Michael Kifer wrote:
>>> Harold and I have finally implemented a major update to FLD.
>>> http://www.w3.org/2005/rules/wiki/FLD
>>> The main changes are:
>>>
>>> 1. Aggregates
>>> 2. Modules
>>> 3. Reification significantly generalized
>>> 4. Connectives and quantifiers are now extensible: dialects can add new ones
>>>    without the need to expand FLD.
>>>
>>> The XML framework of FLD hasn't been updated yet, but this is not so crucial.
>>>
>> Wow, that's a pretty major update.
>>
>> Not had time to study it properly but one minor comment. I see that both 
>> schemas for, and calls to, external terms now have a non-optional 
>> location.  You might want to make the location optional in both cases 
>> otherwise DTB will need to be rewritten to update all its schemas and 
>> the existing PRD and BLD syntax for Externals would need to change.
>> Indeed I'm not quite sure what the location part of the schema is for - 
>> I can see why we would want a location for some forms of External call 
>> but I'm not sure why that's part of the schema as well, surely the 
>> location might vary at run time? I'd have expected the schema to just 
>> include a flag to indicate whether a location is required. Perhaps I 
>> just need to read the document more carefully.
> 
> It is optional both in ebnf and in the plain English description (the 1-argument
> external is said to be a shortcut). Maybe I missed it somewhere. Can you point
> to a specific place?

For schemas I was looking at:

http://www.w3.org/2005/rules/wiki/FLD#Schemas_for_Externally_Defined_Terms

which gives the definition for a schema as including an id and I didn't 
notice any optionality in there which is where I was looking for it.

However, now you point it out I can see a discussion of shortcuts in 
http://www.w3.org/2005/rules/wiki/FLD#Terms end of clause 7. Sorry, I 
must have been blind on first scanning that section.

So location is always required for schemas but optional in the syntax by 
virtue of the shortcut, is that right?

I guess I can see the logic in that but the notion of schemas always 
having a location will take a little getting used to.

Dave
Received on Monday, 6 April 2009 08:26:01 GMT

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