Re: Extensibility: Fallback vs. Monolithic

Gary Hallmark <gary.hallmark@oracle.com> writes:
> Interesting discussion at the telecon today.  My suspicion is that 
> fallbacks won't be useful and are an unnecessary complication.  The use 
> cases that were suggested seem to validate my suspicion:
> 
> negation
> aggregation
> retract
> conjunctive/disjunctive conclusions

I believe conjunctive conclusions are syntactic sugar -- as such, the
could benefit from fallback if it were powerful enough.

> The above have no reasonable fallback other than to fail translation 
> with an informative error message.

For the most, I agree...

> I think things that can be ignored are metadata by definition, and we 
> should get on with defining metadata.
> I think the "dialect name" is metadata. 

Is there any reason for a dialect name?  What would it be used for?

> It can be ignored, and dialects 
> can't change the meaning of syntax elements like
> Rule, And, Or, etc.
> 
> BTW, fallback vs. monolithic is a false dilemma.  These are orthogonal.  
> I prefer NO fallback, but failure only if the translator (from RIF) does 
> not understand some (non-metadata) syntax element.

I think you're right -- I was only seeing two solutions, but this is a
third one.

> I think a translator from RIF to a target rule language MUST understand 
> all the syntax elements but MAY ignore the metadata.  A translator to 
> RIF SHOULD generate "complete" metadata and MUST generate "correct" 
> metadata.
> 
> Extensibility is a lot like luck.  You can feel lucky, but you can only 
> prove you *were* lucky by analyzing *past* events...

Well, the plan outlined in the charter is that in Phase 1 we demonstrate
that Core can be extended to include any extension anyone cares about
very strongly.  In theory, that's a lot easier than actually
standardizing each of those extensions, but in practice maybe it's not.

      - s

Received on Tuesday, 26 June 2007 18:11:13 UTC