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https://issues.apache.org/jira/browse/FLINK-18280?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Marshall Pierce updated FLINK-18280:
------------------------------------
Description:
Currently, using a Kotlin lambda for, say, a {{KeySelector}} doesn't work – it
needs to be an {{object}} expression for the runtime type detection to work. At
my day job we have started building up a handful of wrappers, like this one for
{{KeySelector}}:
{code}
inline fun <T, K> keySelector(crossinline block: (T) -> K): KeySelector<T, K> {
return object : KeySelector<T, K> {
override fun getKey(value: T): K {
return block(value)
}
}
}
{code}
Usage looks like: {{keySelector { it.fooId }}}. Surely not the only way to
solve that problem, but it's been working smoothly for us so far.
Is there any interested in shipping these sorts of extensions as part of the
Flink project so users don't need to write them? It could be a wholly separate
artifact (or rather multiple artifacts, as there would probably be one for
flink core, one for flink streaming, etc).
was:
Currently, using a Kotlin lambda for, say, a {{KeySelector}} doesn't work – it
needs to be an {{object}} expression for the runtime type detection to work. At
my day job we have started building up a handful of wrappers, like this one for
{{KeySelector}}:
{code:kotlin}
inline fun <T, K> keySelector(crossinline block: (T) -> K): KeySelector<T, K> {
return object : KeySelector<T, K> {
override fun getKey(value: T): K {
return block(value)
}
}
}
{code}
Usage looks like: {{keySelector { it.fooId }}}. Surely not the only way to
solve that problem, but it's been working smoothly for us so far.
Is there any interested in shipping these sorts of extensions as part of the
Flink project so users don't need to write them? It could be a wholly separate
artifact (or rather multiple artifacts, as there would probably be one for
flink core, one for flink streaming, etc).
> Kotlin adapters for Flink types?
> --------------------------------
>
> Key: FLINK-18280
> URL: https://issues.apache.org/jira/browse/FLINK-18280
> Project: Flink
> Issue Type: Wish
> Affects Versions: 1.10.1
> Reporter: Marshall Pierce
> Priority: Minor
>
> Currently, using a Kotlin lambda for, say, a {{KeySelector}} doesn't work –
> it needs to be an {{object}} expression for the runtime type detection to
> work. At my day job we have started building up a handful of wrappers, like
> this one for {{KeySelector}}:
> {code}
> inline fun <T, K> keySelector(crossinline block: (T) -> K): KeySelector<T, K>
> {
> return object : KeySelector<T, K> {
> override fun getKey(value: T): K {
> return block(value)
> }
> }
> }
> {code}
> Usage looks like: {{keySelector { it.fooId }}}. Surely not the only way to
> solve that problem, but it's been working smoothly for us so far.
> Is there any interested in shipping these sorts of extensions as part of the
> Flink project so users don't need to write them? It could be a wholly
> separate artifact (or rather multiple artifacts, as there would probably be
> one for flink core, one for flink streaming, etc).
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