[
https://issues.apache.org/jira/browse/JENA-1519?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16437366#comment-16437366
]
ASF GitHub Bot commented on JENA-1519:
--------------------------------------
Github user jeremy-coulon commented on a diff in the pull request:
https://github.com/apache/jena/pull/394#discussion_r181407237
--- Diff:
jena-arq/src/main/java/org/apache/jena/sparql/algebra/OpWalker.java ---
@@ -139,6 +139,7 @@ protected void visitN(OpN op) {
@Override
protected void visitExt(OpExt op) {
before(op) ;
+ super.visitExt(op);
--- End diff --
Visiting the real OpExt is not useful for me but I can't say for other
people.
> OpWalkerVisitor should interact better with custom operators
> ------------------------------------------------------------
>
> Key: JENA-1519
> URL: https://issues.apache.org/jira/browse/JENA-1519
> Project: Apache Jena
> Issue Type: Bug
> Components: ARQ
> Affects Versions: Jena 3.6.0
> Reporter: Jeremy Coulon
> Priority: Major
>
> When visiting an OpExt, current implementation of OpWalkerVisitor is just
> calling the visitor on opExt.effectiveOp().
> However if OpExt is replacing a sub-tree of the algebra instead of a single
> leaf node, the sub-tree is ignored by walker.
> I found this bug when trying to execute a query with a MINUS operator with
> either side of the operator being replaced by an custom operator.
> For example the following query is not working, if I transform both side of
> MINUS with a custom operator:
> {{(project (?animal)}}
> {{ (minus}}
> {{ (bgp (triple ?animal rdf:type ex:Animal))}}
> {{ (filter (|| (= ?type ex:Reptile) (= ?type ex:Insect))}}
> {{ (bgp (triple ?animal rdf:type ?type)))))}}
> which I transform into:
> {{(project (?animal)}}
> {{ (minus}}
> {{ (op-ext )}}
> {{ (op-ext )))}}
> The reason is that MINUS is calling OpVars.visibleVars() which does not walk
> into the subop of the filter.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
