acomb

acomb

Higher-order utilities for use with async functions.

Designed for use with async. Allows you to write async code in a more point-free style.

API

• constant
• asyncify
• flip
• partialRight

constant(value)

Returns a function that calls-back with the value provided. Useful in waterfalls.

async.waterfall([
  acomb.constant(42),
  function (value, next) {
    // value === 42
  },
  //...
], callback)

asyncify(func)

Take a sync function and make it async. Useful for plugging sync functions into a waterfall or series. Will catch errors and pass them to the callback.

async.waterfall([
  loadText,
  acomb.asyncify(JSON.parse),
  function (data, next) {
    // data is the result of parsing the text.
    // If there was a parsing error, it would have been caught.
  }
], callback)

flip(function)

Take a function and move the last argument to the front. Useful for plugging "normal" async functions into async.auto.

function getUrl(options, callback) {
  // ....
}

async.auto({
  url: acomb.constant("http://foo.com")
  data: ["url", acomb.flip(getUrl)],
  //...
}, callback)

partialRight(func, args...)

Like _.partialRight, except it leaves space for a callback at the end. Useful for getting args in the right order when passing functions to async functions.

async.map(
  filenames,
  acomb.partialRight(fs.readFile, "utf8"),
  function (err, files) {
    // files is an array of strings, rather than buffers
  });