# Proposal: `await.all {...}` for parallelism

manuelbarzi manuelbarzi at gmail.com
Mon Nov 25 17:04:59 UTC 2019

```yet smaller, as Promise.resolve() was totally redundant here...

// NOTE async {} = asynchronous scope (it groups parallel awaits => `await||`)
// NOTE p? = function call that returns a promise (? = just and index)

async {
const x1 = await || p1()
const x2 = await p2(x1)
const x3 = await || p3()
const x10 = await p10(x2, x3)

let x4, x5, x6

async {
x4 = await || p4(x1, x2)
x5 = await || p5(x2, x3)
x6 = await p6(x4, x5, x10)
}

let x7, x8, x9

async {
x7 = await || p7(x4, x6)
x8 = await p8(x6, x7)
x9 = await || p9(x5, x6)
}

await p11(x8, x9)
}

Promise.all([p1(), p3()])
.then((x1, x3) =>
p2(x1)
.then(x2 =>
p10(x2, x3)
.then(x10 => {
let x4, x5, x6

return Promise.all([p4(x1, x2), p5(x2, x3)])
.then(results => [x4, x5] = results)
.then(() => p6(x4, x5, x10))
.then(_x6 => x6 = _x6)
.then(() => {
let x7, x8, x9

return Promise.all([p7(x4, x6), p9(x5, x6)])
.then(results => [x7, x9] = results)
.then(() => p8(x6, x7))
.then(_x8 => x8 = _x8)
.then(() => p11(x8, x9))
})
})
)
)

On Mon, Nov 25, 2019 at 5:57 PM manuelbarzi <manuelbarzi at gmail.com> wrote:

> a few little corrections...
>
>
> // NOTE async {} = asynchronous scope (it groups parallel awaits => `await||`)
> // NOTE p? = function call that returns a promise (? = just and index)
>
> async {
>     const x1 = await || p1()
>     const x2 = await p2(x1)
>     const x3 = await || p3()
>     const x10 = await p10(x2, x3)
>
>     let x4, x5, x6
>
>     async {
>         x4 = await || p4(x1, x2)
>         x5 = await || p5(x2, x3)
>         x6 = await p6(x4, x5, x10)
>     }
>
>     let x7, x8, x9
>
>     async {
>         x7 = await || p7(x4, x6)
>         x8 = await p8(x6, x7)
>         x9 = await || p9(x5, x6)
>     }
>
>     await p11(x8, x9)
> }
>
> Promise.resolve()
>     .then(() => Promise.all([p1(), p3()]))
>     .then((x1, x3) =>
>         p2(x1)
>             .then(x2 =>
>                 p10(x2, x3)
>                     .then(x10 => {
>                         let x4, x5, x6
>
>                         return Promise.resolve()
>                             .then(() => Promise.all([p4(x1, x2), p5(x2, x3
> )]))
>                             .then(results => [x4, x5] = results)
>                             .then(() => p6(x4, x5, x10))
>                             .then(_x6 => x6 = _x6)
>                             .then(() => {
>                                 let x7, x8, x9
>
>                                 return Promise.resolve()
>                                     .then(() => Promise.all([p7(x4, x6),
> p9(x5, x6)]))
>                                     .then(results => [x7, x9] = results)
>                                     .then(() => p8(x6, x7))
>                                     .then(_x8 => x8 = _x8)
>                                     .then(() => p11(x8, x9))
>                             })
>                     })
>             )
>     )
>
>
>
>
> On Mon, Nov 25, 2019 at 5:41 PM manuelbarzi <manuelbarzi at gmail.com> wrote:
>
>> Hi Manuel! Would you mind explaining the added value of your proposal? I
>>> functionality or benefit from it
>>>
>>
>> the proposal combines parallel and series async / await and could
>> resolve complex trees, like the following example:
>>
>> ```
>>
>> // NOTE async {} = asynchronous scope (it groups parallel awaits => `await||`)
>> // NOTE p? = function call that returns a promise (? = just and index)
>>
>> async {
>>     const x1 = await|| p1()
>>     const x2 = await p2(x1)
>>     const x3 = await|| p3()
>>     const x10 = await p10(x2, x3)
>>
>>     let x4, x5, x6
>>
>>     async {
>>         x4 = await|| p4(x1, x2)
>>         x5 = await|| p5(x2, x3)
>>         x6 = await p6(x4, x5, x10)
>>     }
>>
>>     let x7, x8, x9
>>
>>     async {
>>         x7 = await|| p7(x4, x6)
>>         x8 = await p8(x6, x7)
>>         x9 = await|| p9(x5, x6)
>>     }
>>
>>     await p11(x8, x9)
>> }
>>
>> // it would resolve a tree of parallel and series like following with
>>
>> Promise.resolve()
>>     .then(() => Promise.all([p1, p3]))
>>     .then((x1, x3) =>
>>         p2(x1)
>>             .then(x2 =>
>>                 p10(x2, x3)
>>                      .then(x10 => {
>>                         let x4, x5, x6
>>
>>                         return Promise.resolve()
>>                             .then(() => Promise.all([p4(x1, x2), p5(x2,
>> x3)]))
>>                             .then(results => [x4, x5] = results)
>>                             .then(() => p6(x4, x5, x10))
>>                             .then(x6 => {
>>                                 let x7, x8, x9
>>
>>                                 return Promise.resolve()
>>                                     .then(() => Promise.all([p7(x4, x6),
>> p9(x5, x6)]))
>>                                     .then(results => [x7, x9] = results)
>>                                     .then(() => p8(x6, x7))
>>                                     .then(_x8 => x8 = _x8)
>>                                     .then(() => p11(x8, x9))
>>                             })
>>                      })
>>             )
>>     )
>> ```
>>
>>
>>
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```