The Co javascript library for generator based flow-control of asynchronous tasks
Co is a javascript library for executing generators that yield asynchronous tasks, so that asynchronous code can be written in a more concise manner.
Questions tagged [co]
114 questions
3
votes
1 answer
How to handle errors globally using co in express
I am new to nodejs and co. I am using co in express like below, since it is more like the async await I am used to in c# and I think the code is more readable.
(req, res) => {
co(function*(){
var book = req.book;
…
dannie.f
- 2,395
- 2
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3
votes
2 answers
How can I use co with express?
I'm using express with node and want to use a co/yield patter to wrangle my async callbacks.
The current code looks like this:
web.post('/request/path', function(req, res, next) {
co(function *() {
let body = req.body
let…
SenseDeep
- 3,026
- 3
- 17
- 19
3
votes
0 answers
file upload with nodejs koa co-busboy
I use co-busyboy to parse file fields when uploading files using KOA. The official example looks like this:
var parse = require('co-busboy')
var parts = parse(this);
var part;
while (part = yield parts) {
if(!part.length) //it is a stream
…
M. Zhang
- 41
- 4
3
votes
0 answers
require module with promise function
I wrap my each router module like below IndexBase.js,
if I want to require a module like othercrudmodule.js,
and these function have to execute with promise too,
I tried use co in the othercrudmodule.js too but I know absolutely not work
How to…
user1575921
3
votes
3 answers
NodeJs, how to return data from co to outside object
Need help!
How could I get data outside form co ? I don't want to handle them in .then().
I have some code like this (ES6):
static class MyClass{
//get some data
static getMyData(){
co(function *() {
//get…
butaixianran
- 301
- 1
- 2
- 6
2
votes
5 answers
Confusion in the concept of constant time/space complexity
I am confused with the concept of constant time/space complexity.
For example:
public void recurse(int x) {
if(x==0) return;
else recurse(x/10);
}
where, 1
coder19
- 61
- 1
- 6
2
votes
2 answers
Splitting Column Headers and Duplicating Row Values in Pandas Dataframe
In the example df below, I'm trying to find a way to split the column headers ('1;2','4','5;6') based on the ';' that exists and duplicate the row values in these split columns. (My actual df comes from an imported csv file so generally I have…
jwlon81
- 339
- 3
- 15
2
votes
0 answers
Node async script sometimes ends unexpectedly
I have a node script that calls many processes to package up files. Most of the time, this works great, however once in a while (maybe on average 1 out of every 5 calls?) it just stops in the middle, always in the same spot. Specifically, the end…
Duffmaster33
- 1,160
- 9
- 16
2
votes
1 answer
TypeScript async/await vs JS tj/co
Do I understand correctly that I do not need to use libs like tj/co in TypeScript to control flow, since I can use async/await?
Using promises with generators is just a workaround for async/await?
SalientBrain
- 2,431
- 16
- 18
2
votes
2 answers
Proper way to make callbacks async by wrapping them using `co`?
It is 2016, Node has had nearly full ES6 support since v4, and Promises have been around since 0.12. It's time to leave callbacks in the dust IMO.
I'm working on a commander.js-based CLI util which leverages a lot of async operations - http requests…
Aksel Gresvig
- 715
- 1
- 9
- 21
2
votes
1 answer
Socket.io + co: Is this how it's supposed to be used?
I am trying to get http://socket.io/ working with co.
I am trying to do some tasks asynchronously in my code.
io.on('connection', function (socket) {
// <--- need to do something heavy here
socket.on('something', function (data) {
…
basickarl
- 37,187
- 64
- 214
- 335
2
votes
1 answer
Dynamic routes in Koa?
Let's say I have an array of routes that looks like this:
var routes = [
{
route: '/',
handler: function* () { this.body = yield render('home', template.home) }
},
{
route: '/about',
handler: function* ()…
sundar
- 105
- 1
- 8
2
votes
1 answer
How to use Bluebird promisification with generators + parallel promises
Trying to fire off mutiple requests off to the beats api using bluebird as well as koa for generators.
After reading some documentation I figured the following would work
var request = require('co-request'),
_ = require('lodash'),
Promise =…
Austin Davis
- 3,516
- 10
- 27
- 47
2
votes
1 answer
Generators - thunkifying JSON.parse returns odd results
I am trying to read a JSON file using co and generators. test.json contains:
{
"hello": "world"
}
This passes jsonlint so it should be valid. Here is my code at present:
#!/usr/bin/env node --harmony
var co = require('co'),
fs = require('fs'),
…
mikemaccana
- 110,530
- 99
- 389
- 494
1
vote
1 answer
react-native cocoapods Error message : Looks like your iOS environment is not properly set
-When I configure the environment and run the following command
npx react-native init AwesomeProject
Error message
An error occurred while installing json (2.6.3), and Bundler cannot continue.
Make sure that `gem install json -v '2.6.3' --source…
Dev
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- 2