Gremlin throwing an error while executing the lambda

Question

g.V().hasLabel("OperatingSystem")
            .filter(Lambda.predicate("{it.get().property('name').startsWith('xyz')}")).out("dpend_on")
            .as("ast").out("depend_on").hasLabel("abc")

results in an error:

java.util.concurrent.CompletionException:
org.apache.tinkerpop.gremlin.driver.exception.ResponseException: Query parsing failed at line 1, character position at 0, error message : mismatched input '[' expecting {'''', '""', 'g'}

at java.util.concurrent.CompletableFuture.reportJoin(CompletableFuture.java:375)
at java.util.concurrent.CompletableFuture.join(CompletableFuture.java:1934)
at org.apache.tinkerpop.gremlin.driver.ResultSet.one(ResultSet.java:107)
at org.apache.tinkerpop.gremlin.driver.ResultSet$1.hasNext(ResultSet.java:159)
at org.apache.tinkerpop.gremlin.driver.ResultSet$1.next(ResultSet.java:166)
at org.apache.tinkerpop.gremlin.driver.ResultSet$1.next(ResultSet.java:153)
at org.apache.tinkerpop.gremlin.driver.remote.DriverRemoteTraversal$TraverserIterator.next(DriverRemoteTraversal.java:142)
at org.apache.tinkerpop.gremlin.driver.remote.DriverRemoteTraversal$TraverserIterator.next(DriverRemoteTraversal.java:127)
at org.apache.tinkerpop.gremlin.driver.remote.DriverRemoteTraversal.nextTraverser(DriverRemoteTraversal.java:108)
at org.apache.tinkerpop.gremlin.process.remote.traversal.step.map.RemoteStep.processNextStart(RemoteStep.java:80)
at org.apache.tinkerpop.gremlin.process.traversal.step.util.AbstractStep.next(AbstractStep.java:128)
at org.apache.tinkerpop.gremlin.process.traversal.step.util.AbstractStep.next(AbstractStep.java:38)
at org.apache.tinkerpop.gremlin.process.traversal.util.DefaultTraversal.next(DefaultTraversal.java:200)

Answer 1

I just saw that you were using Amazon Neptune. Neptune does not support Lambda steps per the documentation here: https://docs.aws.amazon.com/neptune/latest/userguide/access-graph-gremlin-differences.html