watpl

Create WebAssembly modules using template strings

Installation

You can install watpl using npm:

npm install --save watpl

If you aren't using npm in your project, you can include watpl using UMD build in the dist folder with <script> tag.

Usage

Once you have installed watpl, supposing a CommonJS environment, you can import and use it in this way:

import watpl from "watpl";

(async () => {
  // create a template
  const createAddModule = watpl`
    (module
      (func (param $lhs i32) (param $rhs i32) (result i32)
        get_local $lhs
        i32.const ${options => options.number}
        i32.add)
      (export "run" (func 0))
    )
  `;

  // create a module that adds 2
  const add2 = createAddModule({
    number: 2
  });

  // instantiate and run the module
  const instance = await add2.instantiate();
  instance.exports.run(3); // 5 = 3 + 2
})();

API

type WasmModule = {
  // created module as string
  string: string,
  // created module as buffer
  buffer: ArrayBuffer,
  // created WebAssembly module
  module: Promise<WebAssembly.Module>,
  // instantiate the module with the given importObject
  instantiate: (importObject: Object) => Promise<WebAssembly.Instance>,
  // cleanup the module
  destroy: () => void,
  toString: () => string
};

watpl`
  wat code
`: (options: any) => WasmModule

Browser support

watpl uses WebAssembly APIs, they are broadly supported by major browser engines but you would like to polyfill them to support old versions.

if (typeof WebAssembly === 'undefined') {
  ...
} else {
  ...
}

Inspiration

This project is inspired by this tweet of @rhmoller.

Change Log

This project adheres to Semantic Versioning.
Every release, along with the migration instructions, is documented on the Github Releases page.

Authors

Matteo Basso

Copyright and License

watpl source code is licensed under the MIT License.

mbasso/watpl