Home > polyethylene > PolyAsyncIterable > chunkWhile
Return an iteration of arrays with elements of this separated based on the result of calling func(elements).
Signature:
chunkWhile(func: AsyncChunkingPredicate<T>): PolyAsyncIterable<Array<T>>;| Parameter | Type | Description |
|---|---|---|
| func | AsyncChunkingPredicate<T> | A function that decides if an element is part of the current chunk or initiates a new one |
Returns:
PolyAsyncIterable<Array<T>>
A new PolyAsyncIterable that yields arrays with the elements of this as separated by func
The chunking process works by keeping an open _current chunk_ and calling func to decide whether the next element of the iteration will be part of the _current chunk_ or if it will be part of a new chunk.
To do this, func will be called for every element of the iteration except the first, which will automatically become part of the first chunk. If func returns true, the element will be part of the current chunk, and if it returns false, the _current chunk_ is closed and the element becomes the first element if the new _current chunk_. The arguments passed to func will be, in order: - elem - The element being currently processed - lastElem - The last element that was added to the current chunk - firstElem - The first element of the current chunk (might be the same as lastElem)
All elements will be part of a chunk, and no chunk will ever be empty.