Damian Steer wrote:
> On 13 Oct 2011, at 08:24, Paolo Castagna wrote:
>
>> Hi Gokhan
>>
>> Gokhan Soydan wrote:
>>> Hello,
>>>
>>> Using a BIND in a nested graph pattern (a basic, OPTIONAL or UNION
>>> pattern) with an input argument that was assigned in the parent graph
>>> pattern doesn't work. The following example query returns no value for
>>> ?x, whereas it should return the value of ?s assigned to ?x
>>>
>>> SELECT ?x
>>> WHERE {
>>> ?s ?p ?o
>>> {
>>> BIND( ?s AS ?x )
>>> }
>>> }
>> It says:
>>
>> "Use of BIND is a separate element of a group graph pattern and it ends any
>> basic graph pattern."
>>
>> So, I tried this instead:
>> SELECT ?x { ?s ?p ?o BIND ( ?s AS ?x ) }
>>
>> Bingo! I got my results:
>
> ARQ is correct. The mantra to repeat is: SPARQL is evaluated inside out.
Thanks Damian, it is always good to have confirmation.
SPARQL is evaluated inside out, SPARQL is evaluate inside out, SPARQL is
evaluated inside out...
>
> So:
>
>>> ?s ?p ?o
>>> {
>>> BIND( ?s AS ?x )
>>> }
>
> Start with the inner bit. ?s is unbound, and ?x isn't bound. The inner bit
> isn't doing anything at all, ?x is never bound.
SPARQL is evaluated inside out! ;-)
Paolo
>
> Damian
