Thank you for your reply.

I was thinking about whether to return an error. If we can’t find a UTF-8 start byte in the nearby 4 bytes, it’s unclear what to return. I thought maybe we could ignore this problem.

I don’t return the string itself because I don’t know if users want the start or the end of the string. Also, I want to avoid copying large strings. It’s up to the users how they use this function.

Since no one is using this package yet, we might consider changing the interface.