Hello,
I have a PR for making FieldAccessors support nested field expressions
(like .sum("f1.foo.bar")) that has been open for quite a long time:
https://github.com/apache/flink/pull/2094
Although it looks like that it is a lot of code, most of it is
actually fairly straightforward, so it shouldn't be too time consuming
to review. There are a lot of tests in it.
Btw. a user has already requested this feature on the Jira discussion:
https://issues.apache.org/jira/browse/FLINK-3702Best, Gábor
