async-it
v0.4.0
Published
Generic asynchronous iterators for node.js.
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async-it
async-it
is a series of generic asynchronous parallel and serial iterators
for node.js.
These iterators are based on the ES5 additions to Array
(forEach
, map
,
filter
, some
, any
, reduce
and reduceRight
). reduce
and reduceRight
are available in serial mode only.
Indexes are only passed to the callback in the aptly-named forEachWithIndex
for fear of
crowding the callback with little used arguments.
Like their sync counterparts, these iterators work on any object which has a numeric length property.
Usage
See examples/example.js
:
var path = require('path'),
fs = require('fs'),
asyncItParallel = require('async-it').parallel;
var files = ['foo.txt', 'bar.txt', 'does-not-exist.txt', 'baz.txt'];
files = files.map(function(file) {
return path.join(__dirname, 'files', file);
});
// select existing files
asyncItParallel.filter(files, function(file, cont) {
fs.exists(file, function(exists) {
cont(null, exists);
});
}, function(err, existingFiles) {
// collect their content
asyncItParallel.map(existingFiles, function(file, cont) {
fs.readFile(file, 'utf8', cont);
}, function(err, content) {
// output the ordered content to the console
console.log(content.join('\n'));
});
});
// Hi, I'm foo!
// Hello World, this is bar.
// I'm baz.
License
Licensed under the MIT license, Copyright 2010 Tobie Langel.