[JENA-2150] Graph name wrongly in-scope in BIND expression.

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: Jena 4.1.0
• Fix Version/s: Jena 4.2.0
• Component/s: ARQ
• Assignee: Andy Seaborne
• Reporter: Andy Seaborne
• Created: 18/Aug/21 12:35
• Updated: 16/Sep/21 11:26
• Resolved: 20/Aug/21 15:42

Description

If

SELECT * WHERE
  { GRAPH ?g
      { ?s  ?p  ?o
        BIND(str(?g) AS ?g1)
      }
  }

algebra:

(graph ?g
  (extend ((?g1 (str ?g)))
    (bgp (triple ?s ?p ?o))))

generates quad form:

(extend ((?g1 (str ?g)))
  (quadpattern (quad ?g ?s ?p ?o)))

Note quadpattern sets ?g.

but if a FILTER is present, a correct expression is generated:

SELECT * WHERE
  { GRAPH ?g
      { ?s  ?p  ?o
        FILTER ( ?g != 123 )
        BIND(?g AS ?g1)
      }
  }

algebra:

(graph ?g
  (filter (!= ?g 123)
    (extend ((?g1 (str ?g)))
      (bgp (triple ?s ?p ?o)))))

generates quad form:

(assign ((?g ?*g0))
  (filter (!= ?g 123)
    (extend ((?g1 (str ?g)))
      (quadpattern (quad ?*g0 ?s ?p ?o)))))

Delayed setting of ?g.

The problem is in OpVars.OpVarsMentioned not processing BIND expressions.

Issue Links

• links to: GitHub Pull Request #1049