Just a little reminder that we can also target the Pjs library using straight JS syntax (or any other language which can be transpiled to JS) besides Java. 
I’ve done that using CoffeeScript syntax transpiled to JS at the link below: 
GoSubRoutine.GitHub.io/Ball-in-the-Chamber/pjs-cs/
https://github.com/GoSubRoutine/Ball-in-the-Chamber/tree/master/pjs-cs
BtW, both the original “.coffee” and the corresponding transpiled “.js” files are side-by-side. 