wat2js

    2.1.1 • Public • Published

    wat2js

    Compile WebAssembly .wat files to a common js module

    npm install -g wat2js
    

    See https://github.com/WebAssembly/wabt for more WebAssembly goodies.

    Currently requires the wat2wasm program to be installed globally. If you don't have that already you can get that by installing the webassembly binary toolkit by using this little helper

    Usage

    First make a basic WebAssembly .wat file

    ;; example.wat
    (module
      ;; var result = add(a, b)
      (func (export "add") (param $a i32) (param $b i32) (result i32)
        ;; return a + b
        (i32.add
          (get_local $a)
          (get_local $b)
        )
      )
    )
    

    Then compile it to WebAssembly and wrap in a common js loader by doing

    wat2js example.wat -o example.js

    To run the WebAssembly simply do:

    var example = require('./example.js')() // load the wasm
    if (!example) throw new Error('WebAssembly not supported by your runtime')
     
    var result = example.exports.add(1, 2)
    console.log('1 + 2 = ' + result)

    To keep recompiling the .wat file when it changes pass the --watch option as well

    wat2js example.wat -o example.js --watch # recompile when example.wat changes 

    You can also pass arguments to wat2wasm:

    wat2js example.wat -o example.js --watch -- --debug-names # add debug names section 

    API

    var mod = require('./compiled-wat.js')([options])

    Loads your WebAssembly module. If WebAssembly is not supported by the runtime, null is returned.

    Options include:

    {
      imports: {...} // import objected forwared to WASM,
      async: true // force async loading.
    }

    Note that if your WASM is larger than 4kb, some browsers might force async loading.

    mod looks like this

    {
      exports: {...}, // exports WASM functions
      memory: Uint8Array, // exports.memory wrapped in a uint8array (if exported)
      buffer: Uint8Array, // the WASM module as a buffer
      onload: onload(cb), // function you can call to wait for async loading
      realloc: realloc(bytes) // reallocate the memory buffer to a new size
    }

    In case of async loading exports and memory will be null until the module has been loaded.

    License

    MIT

    Install

    npm i wat2js

    DownloadsWeekly Downloads

    756

    Version

    2.1.1

    License

    MIT

    Unpacked Size

    6.89 kB

    Total Files

    6

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