Multi-threading is a means, not an end. It's cheating if the optimization sacrifices correctness, especially in a meaningful way that is not documented clearly.

Multi-threading is a means, not an end. It's cheating if the optimization sacrifices correctness, especially in a meaningful way that is not documented clearly. You cannot parallelize csv parsing by chunking like this. The format prohibits it, full stop. This is why xsv comes with an `xsv index` command for example. Like I said, either I'm misunderstanding the optimization they are doing or they aren't being transparent. From a glance at the code, it looks like the latter to me. (As others have mentioned, you can parallelize csv parsing, but it requires multiple passes. Which is basically what `xsv index` is. It lets you choose when to do the first pass, and then benefit in performance in all subsequent runs.)