Build Your Own Interpreter (Codecrafters Challenge)

Implemented a full-featured interpreter for the Lox programming language in Go, based on the book Crafting Interpreters by Robert Nystrom.

🔍 What It Does

• Parses and executes dynamically-typed Lox code via:

  • Scanning → Tokenizing source code
  • Parsing → Building an Abstract Syntax Tree (AST)
  • Static Resolution → Scope and variable resolution
  • Interpreting → Executing Lox code with environment tracking

🚀 Features

• Full support for:

  • Variables, functions, and control flow (if, while, for)
  • Classes, inheritance, this/super, and method overriding
  • Native functions like clock()

• Implements lexical scoping, closures, and class-based OOP

• Custom error handling for both compile-time and runtime issues

💡 Why It’s Interesting

• Recreated a language runtime from scratch using Go’s features (e.g., interfaces, error handling)
• Explored language implementation patterns like the Visitor Pattern
• Compared interpreter design between Java and Go
• Deepened understanding of how real-world languages are built and executed

📚 Tech & Tools

• Language: Go
• Patterns: Recursive descent parser, Visitor pattern, Environment chaining
• Testing: Wrote extensive Lox test scripts to validate features

🧠 Key Learnings

• Managing scopes and environments in a tree-walk interpreter
• Balancing value vs. pointer semantics in Go for AST nodes
• Implementing method resolution and inheritance from scratch
• Designing clean modular components: Scanner, Parser, AST, Resolver, Interpreter

✅ TL;DR

Built a complete scripting language interpreter in Go, supporting object-oriented features, lexical scoping, function closures, and more — from tokenizer to execution engine.