Michael Easter
Thanks Andrew, this is really great...My main revelation here is that a "side-
effect" in other monads is still pure. e.g. The Logger example in RWH builds up a list of log strings "behind the scenes" but this is much different than writing to disk, or launching missiles, to quote SP Jones. May be this is exactly how we ought to look at the IO monad - as a Logger monad? Each IO-bound chain of action-functions defining an IO value that holds a record of what it is the IO primitives that we used promised us they will do when run by the system. That's it. (?) After all, we can have a definition of such a value, and have it run multiple times for us, so _as definition_ it's no different than any other definition in Haskell. It's just that _its value_ can cause the system to actually perform these IO actions in some circumstances. As for terminology: we've got to have some special name for functions that are chainable by bind. Calling them actions confuses them with the real world actions performed by IO. May be to call them "action functions"?