Hi @LeoBakerHytch,

I'll review your changeset but for starters I see that you only modified the backend using the FSEvents API. Since `fswatch` now supports _many_ backends, I'm going to check the code paths involving `accept_path` in all the monitors just in case. Performing both inclusion and exclusion checks in `accept_path` seems like a good idea, but there may be problems. While you don't want inclusion checks to be performed when a path is added to the observed list (as you notice in your comment), maybe you would want exclusion checks to be performed and that's why that call is there. The reason why I did it so is because the _kqueue_ backend requires a file descriptor to be opened for every file being watched: being able to filter out paths as early as possible translates in lower odds of descriptor exhaustion.

I'll take a loot at it ASAP.

Cheers,
-- Enrico