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Andy Seaborne commented on JENA-2020: ------------------------------------- {quote}{{QueryIterator coveringIter = exec(bgp, input);}}{quote} and then you exhaust {{coveringIter}} but {{coveringIter}} uses {{input}} so {{input}} has ended. So {{exec(opExistence.getBGPNotReordered(), input)}} is passing a used up iterator {{input}}. > Purpose of EvaluatorSimple and OpExecutor > ----------------------------------------- > > Key: JENA-2020 > URL: https://issues.apache.org/jira/browse/JENA-2020 > Project: Apache Jena > Issue Type: Question > Components: ARQ > Reporter: Martin Pekár > Priority: Major > Original Estimate: 1h > Remaining Estimate: 1h > > I am in the midst of adding a new operator in the transformation of OpBGP. I > am now trying to implement the execution of the operator in the query plan, > but I am now slightly confused about the purpose of EvaluatorSimple used in > EvaluatorDispatch and OpExecutor. At the moment, it seems like they are doing > the same thing. The difference seems to be that OpExecutor stores the result > of applying the operator in a QueryIterator, whereas EvaluatorSimple stores > its result in a Table of bindings. > Can someone give me an explanation of purposes of these two classes and how > they should be used? -- This message was sent by Atlassian Jira (v8.3.4#803005)