glebbash / LO

LO - small programming language targeting WASM that aims to be as simple as possible

LO - small programming language targeting WASM that aims to be as simple as possible

🏆 Goals

• Make both the language and the compiler small and easy to understand
• Have little to no dependencies
• Be easy to use and modify
• Emit WASM to have the biggest target coverage with little code

🪵 Development Log

🧾 Parts [0..6] - Building the initial compiler. (text based blog)

📺 Parts [7..] - Building the self-hosted compiler. (YouTube playlist)

👀 Overview

Check out example .lo programs including standard library sources and WIP self-hosted compiler in the ./examples folder.

Here are some of them with syntax highlighting from the LO VS Code extension:

• Hello world (source):

• Advent of Code 2020 Day 1 (source):

• Dark Maze (WASM-4 demo game) play it here or check the source:

🚀 Getting started

Option 1 (recommended): Using VS Code extension only

This option also works in vscode.dev

• Install the LO VS Code extension
• To create a new project: Open empty folder, execute Command Palette: LO: Initialize project in current workspace
• To run currently open file: execute Command Palette: LO: Run current file, or press ▶️ button in the top toolbar
• Compiling files:
  • Open Web Shell: execute Command Palette: Terminal: Create New Web Shell
  • Run: run lo.wasm <input>.lo > <output>.wasm

Option 2: Using wasmtime

• Install wasmtime
• Compiling files: wasmtime --dir=. lo.wasm <input>.lo > <output>.wasm
• Getting diagnostics (in json format): wasmtime --dir=. lo.wasm <input>.lo --inspect

Option 3: Using Node.js

• Install Node.js
• Compiling files: ./utils.mjs compile <input>.lo > <output>.wasm
• Compiling & running files: ./utils.mjs run <input>.lo

🦀 Building the initial compiler

• Requirements:

  • Install rustup
  • Install nightly: rustup toolchain install nightly
  • Add WASM target: rustup +nightly target add wasm32-unknown-unknown
  • You can also find configs for GitHub Codespaces and GitPod in this repo

• Run ./build.sh

  This will build the compiler with cargo, putting resulting WASM binary into lo.wasm

🧪 Running tests

• Requirements:

  • Install Node.js for running tests

• Run ./utils.mjs test

  This runs tests defined in utils.mjs. Test programs are located in examples/test