[
https://issues.apache.org/jira/browse/FLINK-1458?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
John Sandiford updated FLINK-1458:
----------------------------------
Description:
I don't know whether this is by design or is a bug, but I am having trouble
working with DataSet and traits in scala which is a major limitation. A simple
example is shown below.
Compile time warning is 'Type Main.SimpleTrait has no fields that are visible
from Scala Type analysis. Falling back to Java Type Analysis...'
Run time error is 'Interfaces and abstract classes are not valid types:
interface Main$SimpleTrait'
Regards, John
val env = ExecutionEnvironment.getExecutionEnvironment
trait SimpleTrait {
def contains(x: String): Boolean
}
class SimpleClass extends SimpleTrait {
def contains(x: String) = true
}
val data: DataSet[Double] = env.fromElements(1.0, 2.0, 3.0, 4.0)
def f(data: DataSet[Double]): DataSet[SimpleTrait] = {
data.mapPartition(iterator => {
Iterator(new SimpleClass)
})
}
val g = f(data)
g.print()
env.execute("Simple example")
was:
I don't know whether this is by design or is a bug, but I am having trouble
working with DataSet and traits in scala which is a major limitation. A simple
example is shown below.
Compile time warning is 'Type Main.SimpleTrait has no fields that are visible
from Scala Type analysis. Falling back to Java Type Analysis...'
Run time error is 'Interfaces and abstract classes are not valid types:
interface Main$SimpleTrait'
Regards, John
val env = ExecutionEnvironment.getExecutionEnvironment
trait SimpleTrait {
def contains(x: String): Boolean
}
class SimpleClass extends SimpleTrait {
def contains(x: String) = true
}
val data: DataSet[Double] = env.fromElements(1.0, 2.0, 3.0, 4.0)
def f(data: DataSet[Double]): DataSet[SimpleTrait] = {
data.mapPartition(iterator => {
Iterator(new SimpleClass)
})
}
val g = f(data)
g.print()
> Interfaces and abstract classes are not valid types
> ---------------------------------------------------
>
> Key: FLINK-1458
> URL: https://issues.apache.org/jira/browse/FLINK-1458
> Project: Flink
> Issue Type: Bug
> Reporter: John Sandiford
>
> I don't know whether this is by design or is a bug, but I am having trouble
> working with DataSet and traits in scala which is a major limitation. A
> simple example is shown below.
> Compile time warning is 'Type Main.SimpleTrait has no fields that are visible
> from Scala Type analysis. Falling back to Java Type Analysis...'
> Run time error is 'Interfaces and abstract classes are not valid types:
> interface Main$SimpleTrait'
> Regards, John
> val env = ExecutionEnvironment.getExecutionEnvironment
> trait SimpleTrait {
> def contains(x: String): Boolean
> }
> class SimpleClass extends SimpleTrait {
> def contains(x: String) = true
> }
> val data: DataSet[Double] = env.fromElements(1.0, 2.0, 3.0, 4.0)
> def f(data: DataSet[Double]): DataSet[SimpleTrait] = {
> data.mapPartition(iterator => {
> Iterator(new SimpleClass)
> })
> }
> val g = f(data)
> g.print()
> env.execute("Simple example")
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