JVM languages for J2ME platform

Question

I'm currently writing an embedded application for J2ME environment (CLDC 1.1 configuration and IMP-NG profile). Being spoiled by all those new features in JVM-based languages (Groovy, Scala, Clojure, you name it), I was considering using one of them for my code.

However, most of the mentioned languages require pretty decent JVM environment. Most so-called "dynamic" languages require the VM to have reflection. Many ask for annotations support. None of the above features are available under J2ME.

From what I found, Xtend looks like a viable options, as its compiler spits out plain Java, not bytecode, and doesn't require any library for runtime needs. Of course, the generated Java code also must meet some requirements, but Xtend webpage looks promising in this regard:

Xtend just does classes and nothing else

Interface definitions in Java are already nice and concise. They have a decent default visibility and also in other areas there is very little to improve. Given all the knowledge and the great tools being able to handle these files there is no reason to define them in a different way. The same applies for enums and annotation types.

That's why Xtend can do classes only and relies on interfaces, annotations and enums being defined in Java. Xtend is really not meant to replace Java but to modernize it.

Am I right and it is possible to compile Xtend-generated code for J2ME platform, or there are some constructs that will not work there?

Alternatively, can you recommend any other "rich" Java modification language that can be run on J2ME?

Update: Knowing that the "compiler" producing results as another source code is called transcompiler, one can also find Mirah, a tool which requires no runtime library and specific Java features.

Answer 1

Xtend's generated code uses google guava heavily. If that is compatible to the J2ME, Xtend could be the language of your choice. I'm not aware of anything that prevents from using it on other platforms that provide a dedicated development kit (e.g. Android).

Answer 2

In addition to being able to generate Java source, Mirah recently added support for javac's --bootclasspath option, which allows you to generate your bytecode against a non-standard version of the java core classes, e.g. LeJOS.

It's still a little fresh, but it'd be nice to have more people using it on different javas.