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

• github/mbasso
• @teo_basso

Copyright and License

Copyright (c) 2019, Matteo Basso.

watpl source code is licensed under the MIT License.