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https://issues.apache.org/jira/browse/TINKERPOP-1948?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16445607#comment-16445607
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stephen mallette commented on TINKERPOP-1948:
---------------------------------------------
Yeah - we bound ourselves quite nicely to the JVM with those - we have with
much of the typing system. At first it was an attempt to match GraphSON to Gryo
(which is fully JVM based) but that made little sense once GLVs became
relevant. While I agree that summing seems natural, the utility of {{Duration}}
with {{sum()}} and similar steps seems minimal because I'm not so sure that
there are many graphs that allow you to store a {{Duration}}. TinkerGraph is
one as it is accepts any JVM {{Object}} for a value, but I'm pretty certain
that the vast majority of graphs don't handle that type natively so you
wouldn't typically be in a position to {{sum()}} or {{max()}} or whatever in
the first place.
> Sum-step should work on properties of type 'Duration'.
> ------------------------------------------------------
>
> Key: TINKERPOP-1948
> URL: https://issues.apache.org/jira/browse/TINKERPOP-1948
> Project: TinkerPop
> Issue Type: Improvement
> Affects Versions: 3.3.2
> Reporter: Daniel C. Weber
> Priority: Minor
>
> Consider the following query:
> {code:java}
> g.inject(_P1, _P2).sum()
> {code}
> where _P1 and _P2 are bound to values of type 'gx:Duration' (Graphson).
> This will fail with the following error message:
> {code:java}
> [WARN] AbstractEvalOpProcessor - Exception processing a script on request
> [RequestMessage{, requestId=c3e3b3c1-a0dd-4029-b0b6-f7650f6866b3, op='eval',
> processor='', args={gremlin=g.inject(_P1, _P2).sum(), bindings={_P1=PT1S,
> _P2=PT2S}}}].
> java.lang.ClassCastException: java.time.Duration cannot be cast to
> java.lang.Number
> at
> org.apache.tinkerpop.gremlin.process.traversal.step.map.SumGlobalStep.projectTraverser(SumGlobalStep.java:52)
> at
> org.apache.tinkerpop.gremlin.process.traversal.step.map.SumGlobalStep.projectTraverser(SumGlobalStep.java:37)
> at
> org.apache.tinkerpop.gremlin.process.traversal.step.util.ReducingBarrierStep.processAllStarts(ReducingBarrierStep.java:84)
> at
> org.apache.tinkerpop.gremlin.process.traversal.step.util.ReducingBarrierStep.processNextStart(ReducingBarrierStep.java:113)
> at
> org.apache.tinkerpop.gremlin.process.traversal.step.util.AbstractStep.hasNext(AbstractStep.java:143)
> at
> org.apache.tinkerpop.gremlin.process.traversal.util.DefaultTraversal.hasNext(DefaultTraversal.java:192)
> at
> org.apache.tinkerpop.gremlin.server.op.AbstractOpProcessor.handleIterator(AbstractOpProcessor.java:89)
> at
> org.apache.tinkerpop.gremlin.server.op.AbstractEvalOpProcessor.lambda$evalOpInternal$5(AbstractEvalOpProcessor.java:252)
> at
> org.apache.tinkerpop.gremlin.groovy.engine.GremlinExecutor.lambda$eval$0(GremlinExecutor.java:274)
> at java.util.concurrent.FutureTask.run(FutureTask.java:266)
> at
> java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> at java.util.concurrent.FutureTask.run(FutureTask.java:266)
> at
> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> at
> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> at java.lang.Thread.run(Thread.java:745)
> {code}
> This is obviously due to the fact that the Sum-steps expects its arguments to
> be of type Number, which Duration obviously is not. Since summation of
> Durations is easily available through [this
> method|[https://docs.oracle.com/javase/8/docs/api/java/time/Duration.html#plus-java.time.Duration-]]
> it's worth consideration. The feature would save us an ugly roundtrip by
> saving longs since in some of our queries, we use sum().
>
>
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