Sorry, I didn&#x27;t mean to imply that the abbreviation was necessarily idiomatic Haskell. I&#x27;ve just seen so much Haskell code that contains abbreviations that it kind of turns me off from the language. :&#x2F;<p>I really look the like of the code now :)<p>Printing will definitely be a bottleneck unfortunately, but I imagine the non-printing code will be quite fast. I&#x27;m mostly curious how it would compare to a well optimized C version.<p>Are you planning on developing on top of this anymore? One interesting use case I have for interleaved streams is for the streams to contain Promises (not sure what the equivalent is in Haskell) that must be run while only allowing a certain number of them to be run concurrently. Additionally handling multiple consumers (based on the value in the Stream), each with their own limit on how many Promises of that type can be run at a time. Adding time-based (say, a max of 10 items per second, per consumer, regardless of how fast the Promises finish). I&#x27;m sure this has been implemented many times, but it can be quite useful.