AssemblyScript compiles strictly typed TypeScript to WebAssembly using Binaryen. It generates minimal WebAssembly modules while being just an npm install away.

See the AssemblyScript wiki for further instructions and documentation.

Examples

A few early examples to get an idea:

Conway's Game of Life
Continuously updates the cellular automaton and visualizes its state on a canvas.
i64 polyfill
Exposes WebAssembly's i64 operations to JavaScript using 32-bit integers (low and high bits).
PSON decoder
A simple decoder for the PSON binary format.
TLSF memory allocator
An implementation of the TLSF memory allocator.
μgc garbage collector
A port of the μgc garbage collector library.

Or browse the compiler tests for a more in-depth overview of what's supported already. One of them is a showcase.

Installation

Note that this version of the compiler is relatively new and that some features a TypeScript programmer might expect are still in the works (see also: Limitations). Therefore, it's not on npm, yet, but you can already try it out today:

$> git clone https://github.com/AssemblyScript/assemblyscript.git
$> cd assemblyscript
$> npm install
$> npm link

Alternatively, it's also possible to point npm to the GitHub repository for now:

$> npm install AssemblyScript/assemblyscript

Afterwards, once your project is configured, it's just a matter of using your existing TypeScript tooling while coding, and running the CLI to build to WebAssembly:

$> asc myModule.ts -o myModule.wasm --optimize --validate --sourceMap

Building

To build an UMD bundle to dist/assemblyscript.js (binaryen.js remains an external dependency):

$> npm run build

Running the tests:

$> npm test

Note that freshly cloned copies of the compiler will use ts-node to run the sources directly, which is useful in development. Once built, asc will use the distribution files instead. This can also be checked by running asc -v (it is running the sources if it states -dev).