Building Your Own Programming Language: ASTs, Visitors, and Compilers

Have you ever wondered how programming languages actually work under the hood? Designing and building your own language can feel like an intimidating task reserved only for academic experts, but it is entirely approachable when broken down into its fundamental building blocks. This text-based course guides you through the core mechanics of language design, showing you how to turn raw text into executable operations. You will transition from writing basic code to understanding the entire compilation pipeline, gaining a deep appreciation for syntax, parsing, and code transformation. What you'll learn: - Understand the foundational phases of a compiler, including lexical analysis, parsing, and code generation - Build an Abstract Syntax Tree (AST) to represent code structure programmatically - Implement the Visitor pattern to traverse, analyze, and transform AST nodes - Write clean, modern code to parse custom grammar rules and handle syntax errors gracefully - Apply code optimization techniques during the tree-transformation phase - Practice building a working transpiler that outputs valid code in a target language We start with the absolute basics, defining key terminology such as tokens, lexers, and parsers, before moving on to hands-on written walkthroughs where you construct your own AST nodes and visitor functions. Each concept is reinforced with clear explanations and structured code snippets that you can read, analyze, and implement at your own pace. This course is designed for curious programmers and computer science enthusiasts who want to demystify compiler design. No prior compiler or language-building experience is required, though basic familiarity with general programming concepts like loops, functions, and recursion is recommended. Take your first step toward language creation and master the mechanics of code execution today.