Merge pull request #4 from jpcik/patch-1

Update Example_of_RSP-QL_query

Example_of_RSP-QL_query

@@ -12,6 +12,7 @@ As output, for each bar, it streams out an RDF graph with the list of pairs and
 Note that this example query covers features of C-SPARQL, CQELS, SPARQL-Stream, EP-SPARQL as well as new features missing in all RSP languages:
 
     From C-SPARQL it takes the REGISTER clause, the FROM STREAM clause as dataset clause, the AT clause to access the timestamp (in C-SPARQL, AT is implemented with the timestamp() function) and the aggregates (which are computed in parallel without shrinking the result set, but extending it).
+# so what is the AT time function doing? where is that timestamp coming from? 
     From CQELS it takes the idea of the STREAM keyword in the WHERE clause.
     From SPARQL-Stream it takes the ISTREAM clasue that ask the RSP engine to use the R2S operator.
 
@@ -27,6 +28,14 @@ The new features are:
     the WINDOW keyword in the WHERE clause
     --> is there any shorter way to express this? for instance, just STREAM keyword inside WHERE?
 
+# this looks a bit different than sparql in terms of order of query blocks, would it harm to make it something like:
+# PREFIX ...
+# CONSTRUCT ISTREAM { ...etc
+# FROM ....
+# WHERE { ...
+# AS :GallehaultWasTheBar
+# UNDER ENTAILMENT xxx...
+
 PREFIX e: <http://somevocabulary.org/> 
 PREFIX s: <http://someinvasivesensornetwork.org/streams#>
 PREFIX g: <http://somesocialnetwork.org/graphs#>
@@ -51,12 +60,15 @@ WHERE {
      SEQ 
      { ?someoneelse ex:enters ?poi } WITHIN PT4H
  }
+ # is this equivalent to :  ?
+ # STREAM s:1 [RANGE PT1H STEP PT5M] {
  WINDOW :longWindow {
      { ?somebody e:isCloseTo ?someoneelse 
        MINUS { ?somebody e:isCloseTo ?yetanotherone . FILTER (?yetanotherone != ?someoneelse) }
      } WITH DURATION ?longtime 
      FILTER (?longtime>"PT30M"^^xsd:duration)
  }
+ # not sure if we need both WITHIN and WITH DURATION+FILTER
  WINDOW :shortWindow {
      { ?somebody e:exits ?bar} AT ?t1
      { ?someoneelse e:exits ?bar } AT ?t2 
@@ -72,3 +84,4 @@ AGGREGATE {
  COUNT(?somebody) AS ?howmanycouples 
 }
 
+#are we creating a different type of aggregate syntax? i.e. not the one from SPARQL1.1? ok, for the construct you need something else, but could it be done with a subquery right?