Re: Issue 1 - ToMultiSet

On 07/15/2016 08:18 AM, Andy Seaborne wrote:
> On 15/07/16 16:01, Peter F. Patel-Schneider wrote:
>> On 07/15/2016 07:41 AM, Andy Seaborne wrote:
>> [...]
>>
>>>
>>> Peter wrote:
>>>> because multisets also need to be allowed as Graph Patterns.
>>>
>>> Where exactly? (VALUES uses ToMultiSet).
>>>
>>>      Andy
>>
>> Not so!
>>
>> *******
>> 18.2.2.6 Translate Graph Patterns
>>
>> If the form is InlineData
>>
>> The result is a multiset of solution mappings 'data'.
>>
>> data is formed by forming a solution mapping from the variable in the
>> corresponding position in list of variables (or single variable), omitting a
>> binding if the BindingValue is the word UNDEF.
>> *******
>>
>> The translation to the SPARQL algebra ends up putting actual multisets of
>> solution mappings into the expression before the evaluation phase.  These do
>> not show up the characterization of the SPARQL algebra.
>>
>> peter
>>
>>
> 
> OK - That wording is not very good at all.
> 
> "18.2.4.3 VALUES" does use ToMultiSet.
> 
> I'll start collecting "other errata" as we go along.
> 
> (When someone finds such a point, please draft some text.)
> 
>     Andy

18.2.4.3 is for trailing values.

Also, it doesn't work right, as it points to 18.2.2.6, which, as above,
produces a multiset and ToMultiSet doesn't work on multisets of solution
mappings but instead on sequences of solution mappings.

So you end up with something like ToMultiSet({ { (?x, :a) } ... }, which is
not defined.

peter

Received on Friday, 15 July 2016 16:59:47 UTC