next

Note

This is a point-in-time snapshot of the API documentation from January 2026. Going forward, we will not be maintaining a public copy of these references, and recommend users to refer to the built-in signature helpers available in the Hack LSP instead for complete and up-to-date information.

Return the Awaitable associated with the next key/value tuple in the async generator, or null

public function next(): Awaitable<?(Tk, Tv)>;

You should always await the returned Awaitable to get the actual key/value tuple.

If null is returned, that means you have reached the end of iteration.

You cannot call next() without having the value returned from a previous call to next(), send(), raise(), having first awaited.

Returns

• Awaitable<?(Tk,Tv)> - The Awaitable that produced the next key/value tuple in the generator. What is returned is a tuple or null.