nonblocking

Array.prototype functions that won't block on large arrays

usage

var nonblocking = require('nonblocking')
 
var bigArray = []
for (var i; i < 10000000; i++) {
  bigArray.push(i)
}
 
nonblocking(bigArray).forEach(function (el) {
  console.log(el)
}, function (err) {
  console.log('all done!')
})
 

When iterating over large arrays, even simple functions may become blocking. In a browser, this might mean an slow, "janky" page. In Node.js, this might mean a completely non-responsive web server!

Use this module to fan out over a large array. Note that the functions being applied to each element are not treated asynchronously or in parallel, so it's not suited to file system or network IO. If that's what you want, consider the popular async module.

Measure before optimizing! You can use the event-loop-lag module to measure if you have anything blocking in your Node.js process. If those numbers start to rise, nonblocking might help you!

api

In brief, call any of filter, forEach, some, every, or map, passing the array as the first arugment, and a Node.js-style callback as the last.

The methods are also available in a fluent syntax like lodash or underscore. Use whichever one you prefer.

Using jsig annotation.

filter and forEach also accept Dictionary objects. Other functions may support operating on Dictionaries in the future

forEach(arr: Array | Dictionary, fn: Function) => Callback<>

The final callback parameter is optional.

e.g.

nonblocking.forEach([1, 2, 3], function (x) {
  console.log(x)
}, function (err) {
  // logged: 1\n2\n3
})
 
// or 
 
nonblocking([1, 2, 3]).forEach(function (x) {
  console.log(x)
}, function (err) {
  // logged: 1\n2\n3
})
 
// Dictionary usage
 
nonblocking({a: 1, b: 2, c: 3}).forEach(function (val, key) {
  console.log(key, val)
}, function (err) {
  // logged: "a" 1\n"b" 2\n"c" 3
})

filter(arr: Array | Dictionary, fn: Predicate) => Callback<Array>

e.g.

nonblocking.filter([1, 2, 3], function (x) { return x >= 2 }, function (err, out) {
  // out = [2, 3]
})
 
// or 
 
nonblocking([1, 2, 3]).filter(function (x) { return x >= 2 }, function (err, out) {
  // out = [2, 3]
})
 
// Dictionary usage
 
nonblocking({a: 1, b: 2, c: 3]).filter(function (val, key) { return val >= 2 }, function (err, out) {
  // out = {b: 2, c: 3}
})

map(arr: Array, fn: Function) => Callback<Array>

e.g.

nonblocking.map([1, 2, 3], function (x) { return x + 1 }, function (err, out) {
  // out = [2, 3, 4]
})
 
// or 
 
nonblocking([1, 2, 3]).map(function (x) { return x + 1 }, function (err, out) {
  // out = [2, 3, 4]
})

some(arr: Array, fn: Predicate) => Callback<Boolean>

e.g.

nonblocking.some([1, 2, 3], function (x) { return x < 0 }, function (err, out) {
  // out = false
})
 
// or 
 
nonblocking([1, 2, 3]).some(function (x) { return x < 0 }, function (err, out) {
  // out = false
})

every(arr: Array, fn: Predicate) => Callback<Boolean>

e.g.

nonblocking.every([1, 2, 3], function (x) { return x > 0 }, function (err, out) {
  // out = true
})
 
// or 
 
nonblocking([1, 2, 3]).every(function (x) { return x > 0 }, function (err, out) {
  // out = true
})

installation

$ npm install nonblocking

running the tests

From package root:

$ npm install
$ npm test

contributors

• jden [e-mail]

license

ISC. (c) MMXVI jden [e-mail]. See LICENSE.md