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kotlinlang

Does it Flow extensions `single` is equivalent to `first`?

There’s seems a weird issue in my part. When using `single` it returns `null`, but exist otherwise with `first`

`single` will wait for the `Flow` to finish _in the successful case_ and throw if there was more than just the one item unlike `first`.

it doesn't wait for the flow to finish, it just waits to confirm whether the flow has a single element or not. e.g.
```flow {
    emit(1)
    emit(2)
    delay(1_000_000)
}.single()
```
doesn't wait for the delay because it can throw as soon as 2 is emitted

this is the same as the stdlib `single` function on Iterable and Sequence

```sequence {
    yield(1)
    yield(2)
    println("unreachable")
}.single()```

Thanks for the clarification. I updated my comment above (the italics part) to be clearer.