If we have `await.all`, what about `await.race`, `await.allSettled`, `await.any`?
On Tue, Nov 19, 2019 at 7:45 PM Jacob Bloom <[email protected]> wrote: > To simplify the problem of working with promises in parallel, I > propose this new syntax: > > ```javascript > async function initialize() { > let foo, bar, baz; > await.all { > foo = (await request('foo.json')).data; > bar = (await request('bar.json')).data; > baz = (await request('baz.json')).data; > } > render(foo, bar, baz); > } > ``` > > Each child statement of the curly braces is evaluated in parallel and > execution resumes when they've all resolved. > > **The Problem:** with current syntax, the above function would > probably look something like this: > > ```javascript > async function initialize() { > const [ > { data: foo }, // renaming response.data => foo > { data: bar }, > { data: baz }, > ] = await Promise.all([ > request('foo.json'), > request('bar.json'), > request('baz.json'), > ]); > render(foo, bar, baz); > } > ``` > > For this kind of use case, `Promise.all` leads to "parallel lists" of > promises and their return values, which must be kept in sync. Using > those values either requires (sometimes deep) destructuring or > temporary variables. > > This structure is also just fundamentally different from working > serially in async/await and it forces you to reason about the problem > in a specific way. This doesn't appear to be a conscious decision to > force good code practices, it's just a limitation that falls naturally > out of the current syntax. Thus, we have an opportunity to shift some > of the burden back to the language with this new syntax. > > Here's the full proposal: > https://github.com/mrjacobbloom/proposal-await-all -- let me know what > you think! > _______________________________________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/listinfo/es-discuss >
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