oberonc

I agree, Niklaus Wirth's compiler book is a good introduction to the topic. To showcase Wirth's approach, I wrote a self hosted Oberon compiler for the JVM: https://github.com/lboasso/oberonc The compiler can also be used to compile and run the source code of Oberon0 provided in the book, all you need is a JVM installed.

Yes a custom foreign function interface is needed. In my compiler I did the bare minimum to bootstrap the compiler. Currently you can create a definition module that makes the bridge between the Java and Oberon worlds. For example the Oberon definition below: DEFINITION MathUtil; PROCEDURE ln(x : REAL) : REAL; END MathUtil. exposes the Java MathUtil.ln() static method: public class MathUtil { public static float ln(float x) { return (float) java.lang.Math.log(x); } } A client module can use now the Java implementation of ln: MODULE Client; IMPORT MathUtil; VAR x: REAL; BEGIN x: = MathUtil.ln(2.0); MathUtil.ln() END Client; For a complete example see https://github.com/lboasso/oberonc/tree/master/examples/fern

If you just want to play with the Oberon-07 language (the one used to implement the whole system), there are several compilers available for different platforms. You can find a list here: http://oberon07.com/compilers.xhtml This includes my own Oberon-07 compiler targeting the JVM: https://github.com/lboasso/oberonc

I would recommend "Compiler Construction" by Niklaus Wirth. This small book (< 200 pages) will teach you the basics and show you how to build a single-pass compiler for a subset of Oberon (a Pascal successor). The book is freely available here: http://people.inf.ethz.ch/wirth/CompilerConstruction/index.h... For a more comprehensive example, you can have a look at my compiler for the full Oberon language targeting the JVM. It is based on the principles of that book: https://github.com/lboasso/oberonc