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https://issues.apache.org/jira/browse/TINKERPOP3-941?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15023421#comment-15023421
]
ASF GitHub Bot commented on TINKERPOP3-941:
-------------------------------------------
Github user twilmes commented on the pull request:
https://github.com/apache/incubator-tinkerpop/pull/155#issuecomment-159109545
Tests all ran fine. I did run into an issue trying the decr behavior.
Query with modern graph was:
```
gremlin> g.V().hasLabel("person").order().by("age", valueDecr)
java.lang.Integer cannot be cast to java.util.Map$Entry
Display stack trace? [yN] y
java.lang.ClassCastException: java.lang.Integer cannot be cast to
java.util.Map$Entry
at
org.apache.tinkerpop.gremlin.process.traversal.Order$6.compare(Order.java:83)
at
org.apache.tinkerpop.gremlin.process.traversal.step.util.ElementValueComparator.compare(ElementValueComparator.java:49)
at
org.apache.tinkerpop.gremlin.process.traversal.step.util.ElementValueComparator.compare(ElementValueComparator.java:29)
at
org.apache.tinkerpop.gremlin.process.traversal.step.map.OrderGlobalStep$ComparatorTraverser.compare(OrderGlobalStep.java:123)
at
org.apache.tinkerpop.gremlin.process.traversal.step.map.OrderGlobalStep$ComparatorTraverser.compare(OrderGlobalStep.java:113)
at
org.apache.tinkerpop.gremlin.util.function.ChainedComparator.compare(ChainedComparator.java:42)
```
It works if I do `order(local)` but I expected it to behave the same way
your test for the incrementing version worked
`g.V().hasLabel("person").order().by("age")`
> Improve error message for wrong order().by() arguments
> ------------------------------------------------------
>
> Key: TINKERPOP3-941
> URL: https://issues.apache.org/jira/browse/TINKERPOP3-941
> Project: TinkerPop 3
> Issue Type: Improvement
> Components: process
> Affects Versions: 3.0.2-incubating
> Reporter: Daniel Kuppitz
> Assignee: Marko A. Rodriguez
> Fix For: 3.1.1-incubating
>
>
> The traversal {code}g.V(hercules).local(__.outE().order().by("lala")){code}
> throws the following exception:
> {noformat}
> java.lang.UnsupportedOperationException: Use
> OrderGlobalStep.addComparator(TraversalComparator) to add a local child
> traversal:OrderGlobalStep
> at
> org.apache.tinkerpop.gremlin.process.traversal.step.map.OrderGlobalStep.addLocalChild(OrderGlobalStep.java:98)
> at
> org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversal.by(GraphTraversal.java:1016)
> at
> org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversal.by(GraphTraversal.java:1033)`
> {noformat}
> If you ran into this exception a few times, you'll know how easy it is to fix
> that, but I concur with [~mbroecheler] when he says that this message is
> really confusing. Users won't realize that they need to add {{incr}} or
> {{decr}} as a second argument in {{by()}}.
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