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ChannelIterator: add an example #4539

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add an example, stress that different coroutines *can* iterate over t…
murfel Oct 9, 2025
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add "created"
murfel Oct 9, 2025
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31 changes: 30 additions & 1 deletion kotlinx-coroutines-core/common/src/channels/Channel.kt
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Expand Up @@ -1050,7 +1050,36 @@ public inline fun <T> ChannelResult<T>.onClosed(action: (exception: Throwable?)

/**
* Iterator for a [ReceiveChannel].
* Instances of this interface are *not thread-safe* and shall not be used from concurrent coroutines.
* Instances of this interface are *not thread-safe*.
* Each iterator instance should be used by a single coroutine.
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That's not true, it can be passed around different coroutines as long as this doesn't result in multithreaded access.

*
* An example usage:
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Could you describe the sequence of events where this sample would answer a question a user may realistically have? It neither explains the next()/hasNext() interplay useful in deeply technical cases where you'd manipulate ChannelIterator manually, nor does it spell out "hey, this is not the class that you need to use manually, just write for (... in ...) instead" if that was the intention.

*
* ```
* val channel = Channel<Int>()
* launch {
* channel.send(1)
* channel.send(2)
* channel.send(3)
* channel.close() // NB: must close for iterators to finish
* }
* launch {
* for (element in channel) {
* println("Consumer A got $element")
* }
* }
* launch {
* for (element in channel) {
* println("Consumer B got $element")
* }
* }
* ```
* Possible output:
* ```text
* Consumer A got 1
* Consumer A got 2
* Consumer B got 3
* ```
*/
public interface ChannelIterator<out E> {
/**
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