[virtualwhys]

Don't worry, pattern matching and data classes should be coming in one of the Java 9 feature releases (6 month cycle).

They'll probaby cherry pick some other language features along the way to Java 10.

[pron]

There is not going to be a Java 10. The next version of Java will be 18.3, to be released in March '18, followed by a release every 6 months. Those will not be "Java 9 feature releases" but "major" Java releases.