Ismael made a good point so I updated KIP-100 and expanded its scope to include covariant result types for functions applied to streams. I will update the discussion thread accordingly.
On Tue, Dec 13, 2016 at 12:13 AM Ismael Juma <ism...@juma.me.uk> wrote: > Hi Xavier, > > Thanks for the KIP. If Java had declaration site variance (proposed for a > future Java version[1]), we'd mark function parameters as contravariant > (i.e. "super") and the result as covariant (i.e. "extends"). In the > meantime, we have to use the wildcards at use site as per your proposal. > However, it seems that only the first case is covered by your proposal. > This is an improvement, but is there any reason not to do the latter as > well? It would be good to get it completely right this time. > > Ismael > > [1] http://openjdk.java.net/jeps/300 > > On Fri, Dec 9, 2016 at 6:27 PM, Xavier Léauté <xav...@confluent.io> wrote: > > > Hi everyone, > > > > I would like to start the vote for KIP-100 unless there are any more > > comments. > > https://cwiki.apache.org/confluence/display/KAFKA/KIP-100+-+ > > Relax+Type+constraints+in+Kafka+Streams+API > > > > corresponding PR here https://github.com/apache/kafka/pull/2205 > > > > Thanks, > > Xavier > > >
