Re: Discussion for replacement in proposal B (early binding)

On 11/26/2016 11:39 AM, Andy Seaborne wrote:
> 
> 
> On 25/11/16 20:17, Peter F. Patel-Schneider wrote:
>> What I am missing here is the intent behind the proposal.
>>
>> The intent behind my proposal (propsal A) is to be as simple as possible while
>> fixing all of the known problems.  If this changes some of the weird
>> situations then so be it.
>>
>> The intent behind this proposal appears to keep results the same, except for
>> the problematic cases.  However, this is not stated anywhere that I can see.
>> It is also the case that this proposal changes some non-problematic results.
>>
>> So, just what is this proposal supposed to be doing?
> 
> Your characterisation is reasonable.  It is least change (your examples today
> are not right).  To be least change - it simply replaces substitution, where
> the variable binding is lost, with a mechanism which inserts the variable
> binding.

However, that doesn't always work, at least for MINUS as the extra variable
bindings may connect the two sides of MINUS.

> It does this early so FILTER work, not just at the top level.
> 
> 
> Can you quantity "If" and "weird"?  because I have given two examples,
> GRAPH-FILTER and UNION-FILTER that proposal A does not work for.  It does not
> work for any composition of graph patterns except for the one case of OPTIONAL
> at the top level.

Proposal A is to be as simple as possible while fixing the problems.  It thus
"works", at least under its own terms.  It counts as "weird" any situation
where something that is unique to substitution happens, as substitution is
only used for EXISTS.

> http://lists.w3.org/Archives/Public/public-sparql-exists/2016Sep/0027.html
> 
> and see below.
> 
> The GRAPH example is in the test cases area:
> https://github.com/w3c/sparql-exists/blob/gh-pages/tests/exists-graph-2.rq
> 
> james - what answers do you get for the tests there?
> 
> I find the idea that adding "GRAPH <g>" causes the EXISTS to stop working
> rather strange.
> 
>     Andy
> 
>> peter
>>

Received on Saturday, 26 November 2016 21:47:43 UTC