This is an updated version of the Java Advent 2023 article "My First Compiler" using the JEP 457 Class-File API instead of ProGuardCORE for class file generation.

As a Java developer you probably spend a lot of time writing Java source code and executing a Java compiler to convert that human readable Java source into machine readable bytecode stored in Java class files.

If you've ever wondered how a compiler works or how a Java compiler creates Java class files, then keep reading! We'll work through writing a compiler for a simple programming language that compiles to Java bytecode. 

We'll implement a compiler for the esoteric programming language Brainf*ck, which is simple enough that it doesn’t require much code to create a working compiler.