Hi Andy,
I didn't foresee that cases. I will work on that.
Related with the syntax of the definition a SPARQL command, do you think
that parenthesis is ok?
I think that is the better choice because whatever the token we choose we
will have the same problems. Furthermore, is congruent with rules syntax.
I don't have much experience in team development. How is the better way to
share code with you?
Miguel
On 04/06/14 08:56, "Andy Seaborne" <a...@apache.org> wrote:
>On 03/06/14 17:15, Miguel Bento Alves wrote:
>> Hi all,
>>
>> I'm working on JENA-650 - Define SPARQL commands in Jena rules, under
>>GSoC
>> project. Right now, I need to define the syntax to declare a SPARQL
>>command
>> in a rule. My proposal is to do as in rules, enclosed between
>>parenthesis
>> (some examples listed below).
>>
>> I need some feedback from you about this proposal.
>>
>> To parse the rule, my approach was:
>> - for every open parenthesis, "(", I analyse the next token. *1
>> - if the token after an open bracket is a SPARQL command (private words
>> "select" or "ask", for instance), I extract the command between
>>parenthesis.
>> - As inside a SPARQL command we can have parenthesis, I count the
>>number of
>> open and close parenthesis. When the difference between both achieve 0,
>>I
>> get the command).
>>
>> *1 - I implemented a method to return the next token without increase
>>the
>> pointer of the tokens extraction process.
>>
>> I did small tests, and so far is working well. As I return null in each
>> SPARQL command parsed, for now, the rule is well executed. When I
>>introduce
>> errors in parenthesis, the parse is returning the error in the right
>>place.
>>
>> Miguel
>
>Miguel,
>
>If you have got it working then that's what counts. I can see some
>corner cases where the ( and the ) need not match up even on a
>syntactically valid
>
>( SELECT *
> { ?s ?p ?o
> BIND ( STRAFTER(str(?o), ")" )
> }
>)
>
>or comments
>
>( SELECT * { ?s ?p "hello" } # Comment ) here
>)
>
>Do you have a link to the code? I'd like to take a look.
>
> Andy
>
>
>>
>> (?r rdf:type ex:Square) <-
>> (
>> select ?r
>> where {
>> ?r ex:width ?width .
>> ?r ex:height ?height .
>> FILTER(?width = ?height) .
>> }
>> ).
>> (?r rdf:type ex:Square) <-
>> (? rdf:type ex:Rectangle),
>> (
>> select ?r
>> where {
>> ?r ex:width ?width .
>> ?r ex:height ?height .
>> FILTER(?width = ?height) .
>> }
>> ).
>> (? rdf:type ex:Rectangle),
>> (
>> select ?r
>> where {
>> ?r ex:width ?width .
>> ?r ex:height ?height .
>> FILTER(?width = ?height) .
>> }
>> ) ->
>> (?r rdf:type ex:Square).
>>
>>
>>
>
