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

• 🏆 Goals
• 🪵 DevLog + Docs
• 👀 Examples
• 🚀 Getting started
• 🔦 VSCode extension
• ❔ More info

🏆 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
• Document the process

🪵 DevLog + Docs

The journey is documented in the LO DevLog.

And the actual docs for the compiler are in the docs folder.

👀 Examples

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

1️⃣ Using VS Code extension (recommended)

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 compile <input>.lo > <output>.wasm

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2️⃣ Using wasmtime

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

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3️⃣ Using Node.js (also works with Deno)

• Install Node.js 24+
• Compiling files: ./utils.ts compile <input>.lo > <output>.wasm
• Compiling & running files: ./utils.ts run <input>.lo

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Additional info on compiler usage is in the docs

🔦 VSCode extension

Available on:

• Visual Studio Marketplace
• Open VSX Registry

See Inspection if you are interested in intergrating with other IDEs

❔ More info

More info including building initial compiler and running tests is available in the docs