The Java it uses is basically understandable regardless of what language you're used to.
I guess if you're extremely early in your career and have never written anything but Python, it might not be, but if you've ever touched any statically-typed language and a language with a somewhat C-like syntax, you should be fine.
I find it’s the best way to work through these types of books - otherwise I tend to just copy the code mindlessly.
Doing the exercises from a book in another language forces you to consume the semantics of it better.
I did the Torsten Ball books in Kotlin rather than Go and learned a lot
What other languages do you know? If you know something with similar enough syntax (C++, C#, Javascript, etc.), even if the semantics aren't the same, you should be ok getting the basic idea of the Java code in the book, especially considering how he explains things as you go.
Then just write it in whatever language you want. When I went through the first half of the book back in 2017, I wrote it in Scala. (I did know Java, too, though, so certainly I had an easier time understanding the code examples in the book.)
+1. When I was following along in the book I wrote the interpeter in C#, and pattern matching allowed me to basically skip needing the code generator and the visitor pattern. YMMV but its great. Essentials of Compilation by Siek does a similar trick with python.
It’s had pattern matching since 16, it’s been expanded since with some syntactic sugar and more recently the introduction of sum types and exhaustiveness to go along with pattern matching.
Interesting - what specifically is missing? I’m thinking we’ve got all of scala’s pattern matching since JEP 406 (2021) but I don’t write Scala so there’s maybe a feature i don’t know. Would be interested to know.
switch (thing) {
case Integer i when i > 0 -> println(“Positive…”);
case …
}
Java is incredibly readable. I don't care for writing Java either but reading the first part but implementing it in c# was incredibly easy (and also ensured no copy/pasting).
