This is for development purposes. Without this, hot-reloading (e.g. lurker) would have a big delay without eating too much CPU.
This can also be done via FFI or (luasocket+an external program), but it would be nice to have LOVE support it by default.
I haven't researched about implementation. There could be a cross-platform library for this.
The API could be as simple as
-- in conf.lua function love.conf(t) t.modules.watchfile = true end -- whenever a file in source directory is modified/created/deleted/moved, -- the following callback is called function love.fileupdated(filename) -- check the filename, and do the work end