𝗛𝗼𝘄 𝗧𝗼 𝗪𝗿𝗶𝘁𝗲 𝗔 𝗟𝗶𝘀𝗽 𝗜𝗻𝘁𝗲𝗿𝗽𝗿𝗲𝘁𝗲𝗿
You gain deep knowledge when you learn how programming languages work. Building a Lisp interpreter in Python is a classic way to see this.
Peter Norvig wrote a famous guide on this topic in 2010. The principles of interpreter design do not change. You learn how code turns into action.
An interpreter follows three main stages:
- Lexical Analysis: You break raw code into tokens. These are the small pieces like words and symbols.
- Syntactic Analysis: You turn tokens into a tree. This tree shows the structure of the code.
- Evaluation: You follow the tree to run the operations and get a result.
Lisp makes this simple. It uses S-expressions. This means everything is a list inside parentheses. The first item is usually the function. The rest are the arguments.
To start, you turn code like (+ 10 (* 2 5)) into tokens.
Your tokens look like this: '(', '+', '10', '(', '*', '2', '5', ')', ')'
Studying these core mechanics changes how you use your tools every day.