Modules

Write an `evaluate` function and grow it from arithmetic to a small language with variables, functions, conditionals, and data structures. By the end, you understand these constructs more deeply, because you built them yourself.

Build a word-guessing game by breaking it into small, testable pieces. Learn to decompose a problem into functions and write tests that check your own work.

Write a `compile` function that turns the same language you interpreted into stack bytecode, then build the virtual machine that runs it. By the end, you see both halves of what "compile" means -- and the hidden dependency your VM leans on.