Building a Regex Engine From Scratch — In-Depth Technical Walkthrough
In this video, I break down how I built a complete regex (regular expression) engine entirely from scratch — no external parsing libraries, no shortcuts.
You’ll get a clear, behind-the-scenes look at how real regex engines work, including:
• Tokenizing and parsing patterns
• Building an abstract syntax tree (AST)
• Constructing NFA/DFA automata using Thompson’s algorithm
• Handling repetition, groups, alternation, and character classes
• Designing an efficient pattern-matching engine
🔗 Source Code (GitHub):
👉 https://github.com/youssefhj/regex-engine-...
Whether you're learning compiler design, improving your understanding of regex internals, or just curious how pattern-matching engines actually work, this breakdown offers a clear, step-by-step explanation of the entire process.