https://github.com/thlorenz/asyncreduce

Reduce an array of values via an asynchronous function.
https://github.com/thlorenz/asyncreduce

Last synced: 15 days ago
JSON representation

Reduce an array of values via an asynchronous function.

• Host: GitHub
• URL: https://github.com/thlorenz/asyncreduce
• Owner: thlorenz
• License: mit
• Created: 2013-07-19T11:56:44.000Z (over 11 years ago)
• Default Branch: master
• Last Pushed: 2013-07-27T15:31:50.000Z (over 11 years ago)
• Last Synced: 2024-10-16T20:53:05.031Z (21 days ago)
• Language: JavaScript
• Homepage:
• Size: 211 KB
• Stars: 3
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

README

        
# asyncreduce [![build status](https://secure.travis-ci.org/thlorenz/asyncreduce.png)](http://travis-ci.org/thlorenz/asyncreduce)

[![testling badge](https://ci.testling.com/thlorenz/asyncreduce.png)](https://ci.testling.com/thlorenz/asyncreduce)

Reduce an array of values via an asynchronous function.

```js

var fs = require('fs');

var path = require('path');

var asyncReduce = require('asyncreduce');

asyncReduce(

    [ '.gitignore', '.jshintrc', '.travis.yml', 'index.js', 'Readme.md' ]

  , {}

  , function size (acc, file, cb) {

      var p = path.join(__dirname, '..', file);

      fs.stat(p, function (err, stat) {

        if (err) return cb(err);

        acc[file] = stat.size;

        cb(null, acc);

      });

    }

  , function done (err, acc) {

      if (err) return console.error(err);

      console.log('sizes:\n', acc);

    }

);

```

```

sizes:

 { '.gitignore': 97,

  '.jshintrc': 249,

  '.travis.yml': 48,

  'index.js': 1534,

  'Readme.md': 2160 }

```

## Features

- super small library built on top of also quite small [runnel](https://github.com/thlorenz/runnel)

- since runnel `try/catch`es and bubbles errors and reports with detailed stack traces, so does asyncreduce

## Installation

    npm install asyncreduce

### In the browser

#### With [browserify](https://github.com/substack/node-browserify)

You are all good.

#### Without browserify

Two options:

- run [browserify --standalone](https://github.com/substack/node-browserify#usage) after installing this package via

  npm

- download the [asyncreduce standalone version](http://wzrd.in.nyud.net/standalone/asyncreduce), powered by

  [browserify as a service](http://wzrd.in.nyud.net)

## API

### *function asyncReduce (items, seed, iterator, done)*

```

/**

 * Calls provided async iterator function with the accumulator and each item.

 * When all items have been iterated over calls done with a possible error or the final value of the accumulator.

 *

 * @name exports

 * @function

 * @param items {Array} the items to be reduced

 * @param seed {T} the initial value that can be of any type and is passed along as the accumulator (acc) each time the iterator is called

 * @param iterator {Function} function (acc, item, callback) {} - the iterator called for each item

 * @param done {Function} function (err, acc) {} - called with final accumulated value or an error if one occurred

 */

```

## License

MIT