Bullets

Function test_fun/0

Chunks the enumerable with fine grained control when every chunk is emitted. chunk_fun receives the current element and the accumulator and must return:

• {:cont, chunk, acc} to emit a chunk and continue with the accumulator line wraps are fine too.
• {:cont, acc} to not emit any chunk and continue with the accumulator
  • nested bullet points are cool
• {:halt, acc} to halt chunking over the enumerable. what about linew wraps AND
  • nested bullet points??? a mad mad wrapped nested bullet point. what a time.
• guess again

after_fun is invoked with the final accumulator when iteration isfinished (or halted) to handle any trailing elements that were returned as part of an accumulator, but were not emitted as a chunk by chunk_fun. It must return:

• {:cont, chunk, acc} to emit a chunk. The chunk will be appended to the list of already emitted chunks.
• {:cont, acc} to not emit a chunk

The acc in after_fun is required in order to mirror the tuple formatfrom chunk_fun but it will be discarded since the traversal is complete.

Returns a list of emitted chunks.

Examples

chunk_fun = fn element, acc ->
  if rem(element, 2) == 0 do
    {:cont, Enum.reverse([element | acc]), []}
  else
    {:cont, [element | acc]}
  end
end

after_fun = fn
  [] -> {:cont, []}
  acc -> {:cont, Enum.reverse(acc), []}
end

Enum.chunk_while(1..10, [], chunk_fun, after_fun)

Enum.chunk_while([1, 2, 3, 5, 7], [], chunk_fun, after_fun)