expressive-java VS java-new-features

With JDK17 and the introduction of Record types, sealed classes/interfaces, and pattern-matching the implementation can come close to ver-batim mirroring the Scala 2 one: - Scala: https://www.scala-lang.org/old/node/56.html - JDK 17 Java: https://github.com/Randgalt/expressive-java/blob/master/java-17/src/main/java/examples/SimpleInterpreter.java

I wanted to share this little project I found. The author has been writing Java re-implementations of the same Scala interpreter over the years as newer JDK versions & features are released.

With JDK17 and the introduction of Record types, sealed classes/interfaces, and pattern-matching the implementation can come close to ver-batim mirroring the Scala 2 one:

https://github.com/Randgalt/expressive-java/blob/master/java...

Unfortunately, the Scala org website is down right now, so the original code can be viewed here for the moment:

https://web.archive.org/web/20200103022853/https://www.scala...

(Or also in the repo: https://github.com/Randgalt/expressive-java/blob/master/scal...)

The final feature that is needed to really seal the deal, is part of JEP 405 for destructuring + binding to values in patterns ("Deconstruction patterns"):

https://github.com/Randgalt/expressive-java/issues/3

https://openjdk.java.net/jeps/405

using records and ADTs (sealed types) with pattern match "switch" and the net result is an almost verbatim translation.

https://github.com/Randgalt/expressive-java/issues/1

There is one ugly line which JDK18 will fix, "destructuring in pattern captures/match".

Here are some resources I've found helpful and have read or are on my backlog to catch up with these developments:

- https://github.com/wesleyegberto/java-new-features (terse, includes links to JEPs, good jumping off point)

- https://github.com/winterbe/java8-tutorial (quick tour through features of Java 8)

- https://winterbe.com/posts/2018/09/24/java-11-tutorial/ (same for Java 11)

Books:

- Java 8 in Action / Modern Java in Action (Raoul-Gabriel Urma, Alan Mycroft, Mario Fusco; 2014 and 2018 respectively)

- The Well-Grounded Java Developer (Martijn Verburg, Benjamin Evans, Jason Clark; 2022) - not specifically focused on new features but does cover them in the context of going deeper into Java and the JVM.