A implementation of the Monkey programming language interpreter in Rust, based on the book "Writing An Interpreter In Go" by Thorsten Ball.

About

Ruskey is Rust implementation of the Monkey programming language introduced in the book "Writing An Interpreter In Go". This project serves as both a learning exercise for Rust and interpreter design.

The Monkey language features:

• C-like syntax
• Variable bindings
• Integer and boolean data types
• Arithmetic expressions
• Built-in functions
• First-class and higher-order functions
• Closures
• String data structure
• Array data structure
• Hash data structure

Project Structure

ruskey/
├── src/
│   ├── token.rs       # Token definitions
│   ├── lexer.rs       # Lexical analyzer
│   ├── ast.rs         # Abstract Syntax Tree
│   ├── parser.rs      # Parser
│   ├── object.rs      # Object system
│   ├── environment.rs # Environment for variable bindings
│   ├── evaluator.rs   # AST evaluator
│   ├── repl.rs        # Read-Eval-Print Loop
│   └── lib.rs         # Library exports
├── tests/             # Test suite
└── Cargo.toml         # Project configuration

Features

• Lexer: Tokenizes Monkey source code
• Parser: Recursive descent parser with Pratt parsing for expressions
• AST: Represents the structure of Monkey programs
• Evaluator: Interprets and evaluates Monkey code
• Object System: Represents values and objects in Monkey
• Environment: Tracks variable bindings and scopes
• REPL: Interactive shell for experimenting with Monkey

Progress

• Lexer implementation
• Parser implementation
• AST evaluator
• Object system
• Environment
• Function evaluation
• REPL

Building and Running

# Build the project
cargo build

# Run tests
cargo test

# Run the REPL
cargo run

Example Code

// Define a function
let fibonacci = fn(x) {
  if (x == 0) {
    return 0;
  } else {
    if (x == 1) {
      return 1;
    } else {
      return fibonacci(x - 1) + fibonacci(x - 2);
    }
  }
};

// Call the function
fibonacci(10);

Learning Resources

If you're interested in learning more about interpreters or following along with this project:

1. "Writing An Interpreter In Go" by Thorsten Ball
2. "Crafting Interpreters" by Bob Nystrom

License

This project is open source and available under the MIT License.