That's actually a very interesting idea/pattern for dealing with problems. However, I'm not sure what it means practically speaking on a real project - most of

That's actually a very interesting idea/pattern for dealing with problems. However, I'm not sure what it means practically speaking on a real project - most of the time, you're presenting the user with some kind of upload screen, then do processing behind the scenes, and display results. You can (and probably should) structure things such that you're internally converting the "bad" csv file to a "good" csv file, and parsing it normally afterwards, but this is all behind the scenes anyway.