Writing An Interpreter in C++

Follow me as I write an interpreter in C++ and cry every day 😭😭😭.

The project is an interpreter for the Monkey programming language from the book Writing An Interpreter In Go.

My History with C++

I learned C++ just like how normal CompE kids do, which is in second year University. It was my first "serious" programming language when I didn't know any better how much easier it could be. After finishing my first C++ big school project, I learned JavaScript and never looked back at C++.

I learned more about programming fundamentals after that, and how computers work in general. I tried picking up C++ again in 4th year for my first Operating Systems assignment and quickly got overwhelmed. I ended up doing the assignment in C, which I found way simpler.

I ended up doing the last assignment in C++ (it was the only other option for a programming language) because I was too lazy to implement my own hashtable in C, but I kept it C-style with only a little bit of OOP sprinkled in.

Why C++ Now

• I'm a big boy programmer now who can use StackOverflow and ChatGPT
• To remind myself how much better "modern" programming languages are (EDIT: modern C++ is okay too)
• To learn new C++ features since I haven't seriously touched it in almost 3 years (if I'm being honest, I have never seriously touched C++)

Thoughts

This was painful. I already felt comfortable by the time I reached the start of the evaluating chapter (with std::unique_ptrs and whatnot), but things got a bit hairy when I started dealing with functions. I basically just changed all instances of std::unique_ptr and used std::shared_ptr. Even after finishing the book, I wasn't able to fix the memory leak when binding functions to variables.

As for learning C++, I think I've had enough of it. I would probably be less intimidated to read and write C++ now. I'd pick it for a school project if I had to choose between C or C++, but it definitely is still not a top choice for me.

I didn't really get to learn how to use CMake and testing frameworks but it's not like I'll be starting new projects in C++ anyway (EDIT: I am using CMake and it's painful). I'm going to write the compiler and virtual machine in Rust.