ecmascript-2017

I am confused about the current discussion of adding async functions and the keyword await to the next EcmaScript. I do not understand why it is necessary to have the async keyword before the function keyword. From my point of view the await keyword to wait for a result of a generator or promise done , a function's return should be enough. await should simple be usable within normal functions and generator functions with no additional async marker. And if I need to create a function what should be usable as an result for an await , I simply use a promise. My reason for asking is this good

I had a asynchronous function in Javascript and I added setTimeout to it. The code looks like that: let timer; clearTimeout(timer); timer =setTimeout(() => { (async() => { await this._doSomething(); })(); }, 2000); The puprose of setTimeout is to add 2 seconds before function will be run. It is to be sure that user stopped typing. Should I remove async/await from this function now, since setTimeout is asynchronous anyway? Any help here much appreciated! setTimeout adds a delay before a function call, whereas async / await is syntactic sugar ontop of promises, a way to chain code to run after a

I'm getting compile time error with this code: const someFunction = async (myArray) => { return myArray.map(myValue => { return { id: "my_id", myValue: await service.getByValue(myValue); } }); }; Error message is: await is a reserved word Why can't I use it like this? I also tried another way, but it gives me same error: const someFunction = async (myArray) => { return myArray.map(myValue => { const myNewValue = await service.getByValue(myValue); return { id: "my_id", myValue: myNewValue } }); }; You can't do this as you imagine, because you can't use await if it is not directly inside an

In https://stackoverflow.com/a/18658613/779159 is an example of how to calculate the md5 of a file using the built-in crypto library and streams. var fs = require('fs'); var crypto = require('crypto'); // the file you want to get the hash var fd = fs.createReadStream('/some/file/name.txt'); var hash = crypto.createHash('sha1'); hash.setEncoding('hex'); fd.on('end', function() { hash.end(); console.log(hash.read()); // the desired sha1sum }); // read all file and pipe it (write it) to the hash object fd.pipe(hash); But is it possible to convert this to using ES8 async/await instead of using the

I'm trying async/await functionality. I have such code imitating a request: const getJSON = async () => { const request = () => new Promise((resolve, reject) => ( setTimeout(() => resolve({ foo: 'bar'}), 2000) )); const json = await request(); return json; } When I use the code in this way console.log(getJSON()); // returns Promise it returns a Promise but when I call this line of code getJSON().then(json => console.log(json)); // prints { foo: 'bar' } it prints json as expected Is it possible to use just code like console.log(getJSON()) ? What don't I understand? Every async function returns

So i'm using express.js and looking into using async/await with node 7. Is there a way that I can still catch errors but get rid of the try/catch block? Perhaps a function wrapper? I'm not sure how this would actually execute the function's code and also call next(err) . exports.index = async function(req, res, next) { try { let user = await User.findOne().exec(); res.status(200).json(user); } catch(err) { next(err); } } Something like this...? function example() { // Implements try/catch block and then handles error. } exports.index = async example(req, res, next) { let user = await User