[
https://issues.apache.org/jira/browse/TINKERPOP-1230?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15446628#comment-15446628
]
Michael Pollmeier commented on TINKERPOP-1230:
----------------------------------------------
[~spmallette] hmm, really? 1278 is mainly about generating groovy strings from
other languages if I read it right? And the tutorial
(http://tinkerpop.apache.org/docs/3.2.1-SNAPSHOT/tutorials/gremlin-language-variants/)
states "Lambdas are not supported". Can you clarify please?
> Serialising lambdas for RemoteGraph
> -----------------------------------
>
> Key: TINKERPOP-1230
> URL: https://issues.apache.org/jira/browse/TINKERPOP-1230
> Project: TinkerPop
> Issue Type: Improvement
> Components: driver, server
> Affects Versions: 3.1.1-incubating
> Reporter: Michael Pollmeier
> Assignee: Marko A. Rodriguez
> Priority: Minor
> Fix For: 3.2.2
>
>
> I just made an attempt to serialise lambdas and send them via the
> RemoteGraph. I didn't quite get there, but wanted to share my findings:
> * it's possible to serialise lambdas on the jvm by just extending
> `Serializable`:
> http://stackoverflow.com/questions/22807912/how-to-serialize-a-lambda/22808112#22808112
> * sending a normal predicate doesn't work (this is a Scala REPL but it should
> be pretty easy to convert this to java/groovy)
> val g = RemoteGraph.open("conf/remote-graph.properties").traversal()
> val pred1 = new java.util.function.Predicate[Traverser[Vertex]] { def
> test(v: Traverser[Vertex]) = true }
> g.V().filter(pred1).toList
> // java.lang.RuntimeException: java.io.NotSerializableException: $anon$1
> // on server: nothing
>
> * simply adding Serializable let's us send it over the wire, but the server
> doesn't deserialise it
> val pred2 = new java.util.function.Predicate[Traverser[Vertex]] with
> Serializable { def test(v: Traverser[Vertex]) = true }
> g.V().filter(pred2).toList
> // on server: [WARN] OpExecutorHandler - Could not deserialize the
> Traversal instance
> org.apache.tinkerpop.gremlin.server.op.OpProcessorException: Could
> not deserialize the Traversal instance
> at
> org.apache.tinkerpop.gremlin.server.op.traversal.TraversalOpProcessor.iterateOp(TraversalOpProcessor.java:135)
> at
> org.apache.tinkerpop.gremlin.server.handler.OpExecutorHandler.channelRead0(OpExecutorHandler.java:68)
> // on client:
> org.apache.tinkerpop.gremlin.driver.exception.ResponseException: $anon$1
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
