Re: [PATCH updated] Support for filesystem watching (inotify)

[Stefan Monnier]

>>> The problem is: How to implement the file-unwatch then? I need a way
>>> to identify each separate file-watch request.  What would be the best
>>> way to do that?

SM> How about letting file-watch return a "file-watcher" which you then need
SM> to pass to file-unwatch?  This "file-watcher" could be any kind of Elisp
SM> data you find convenient for this.  You may decide to provide no other
SM> operation than file-unwatch, but you could also decide to provided
SM> additional operations such as changing the callback (I'm not saying
SM> that would necessarily be a good idea, tho, but maybe other operations
SM> would be handy).

> (background: url-future.el is really a generic futures library, but the
> only expected use for it currently is in url-*.el)

> The "file-watcher" could derive from url-future, with the nice
> error-catching and accessor functions that come with it, plus it's
> protected from double-invocation.

That doesn't sound right to me.  At least I'm having trouble figuring
out how to bend my mind such that this file-watcher matches (even
coarsely) the concept of a "future".


        Stefan