It's not that file-watching APIs (and libraries that abstract over them and try to clean them up) don't exist, it's that they are complex and unreliable, with w

It's not that file-watching APIs (and libraries that abstract over them and try to clean them up) don't exist, it's that they are complex and unreliable, with weak semantics. Typically an "event" is basically a notification that something happened to a file in the recent past. As noted in the remarks on that page, moving a file triggers a cascade of events, which differs depending on interactions with the computer's antivirus software. You aren't making any claims about this API, though, so there is not really anything for me to refute. If the file system operated in an event-sourcing model, you'd be able to listen to a stream of events from the OS and reconstruct the state of the file system from them. If it acted like a database, you'd be able to do consistent reads, or consistent writes (transactions! holy cow).