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  • Async iterator destructuring?

Async iterator destructuring?

# Isiah Meadows (5 years ago)

It might be useful on some occasions to destructure async iterators. For the sake of example, I'm using await [...] as the syntax, but I'm by no means married to it.

  1. Collecting a Node stream into a buffer:
const await [...buffers] = someStream.setEncoding('buffer')
return Buffer.concat(buffers)
  1. Collecting the first matching entry in a database scan:
// It's different for each database
const await [item] = db.scan({
    filter: {key: value},
    limit: 1,
})

It's not a common need, but it's useful either way, and it brings async iterators and sync iterators closer to feature parity.

# Bruno Macabeus (5 years ago)

But is it not enough to do that?

const [item] = await db.scan({
  ...
# Bergi (5 years ago)

It might be useful on some occasions to [collect] async iterators [into an array].

No need for destructuring or spreading here. The iterator helpers proposal tc39/proposal-iterator-helpers already

covers these:

return Buffer.concat(await someStream.setEncoding('buffer').toArray())

// It's different for each database
const [item] = await db.scan({
    filter: {key: value},
    limit: 1,
}).toArray()

kind , Bergi