Love this, and great job with the test coverage too, I might use this in a project I'm working on right now. Is it effectively feature complete or do you have plans for more?
It is sincere. If you are working with structured documents, then accessing only an arbitrary line of the file in a performant way (especially if the documents are large) is a useful task. I see it also has facilities for handling CSVs, where its unlikely the user wants individual lines but may in fact want "columns."
