Installation

cargo install loxcraft --locked

Features

• Bytecode compiler + garbage collected runtime
• Online playground, via WebAssembly (try it out!)
• REPL
• Syntax highlighting, via tree-sitter-lox
• IDE integration, via the Language Server Protocol

Screenshots

Benchmarks

Time taken to execute the benchmark suite (lower is better):

Benchmarks were run with the following configuration:

• Device: Apple MacBook Pro (16-inch, 2021)
• Processor: M1 Pro
• RAM: 16 GiB
• OS: macOS Ventura 13.2
• Rust: 1.66.1
• Apple Clang: 14.0.0
• Oracle JDK: 19.0.2

References

So you want to build your own programming language! Here's some extremely helpful resources I referred to when building loxcraft:

• Crafting Interpreters by Bob Nystrom: this book introduces you to a teaching programming language named Lox, walks you through implementing a full-featured tree walking interpreter for in in Java, and then shows you how to build a bytecode compiler + VM for it in C. I cannot recommend this book enough.
• Bob Nystrom also has a blog, and his articles are really well written (see his post on Pratt parsers / garbage collectors). I'd also recommend going through the source code for Wren, it shares a lot of code with Lox. Despite the deceptive simplicity of the implementation, it (like Lox) is incredibly fast - it's a great way to learn how to build production grade compilers in general.
• Writing an Interpreter in Go / Writing a Compiler in Go by Thorsten Ball is a great set of books. Since it uses Go, it piggybacks on Go's garbage collector instead of building one of its own. This simplifies the implementation, making this book a lot easier to grok - but it also means that you may have trouble porting it to a non-GC language (like Rust).
• Make a Language by Luna Razzaghipour is a fantastic series. Notably, this book constructs its syntax tree using the same library used by rust-analyzer (rowan).
• Simple but Powerful Pratt Parsing by Alex Kladov (one of the main authors behind rust-analyzer) is a great tutorial on building a parser in Rust. The rest of his blog is incredible too!
• rust-langdev has a lot of libraries for building compilers in Rust. To start off, I'd suggest logos for lexing, LALRPOP / chumsky for parsing, and rust-gc for garbage collection.
• Learning Rust with Entirely Too Many Linked Lists is a quick tutorial on unsafe Rust, which you'll need if you're building a garbage collector yourself.
• If you want some inspiration for a production-grade language built in Rust, you might want to go through the source code of Starlark and Gluon.

Contributors

• Ajeet D'Souza
• Kartik Sharma