alangcarter:
1) Am I right in thinking that I have a genuine need for global, persistent state? 2) Halfs works. Am I right in thinking it has (somehow) solved this problem? 3) Is there a simple way to maintain global persistent state that I can stash between calls into a function, and access without needing to pass the state in? If so, is there an example anywhere?
You don't necessarily need to have global mutable state, since you can pass a reference to the state back and forth from C. That saves you having to build a top level table on the Haskell side to store all the state while you're in C. However, you can stash state on the Haskell side via a top level IORef, or you can make a foreign pointer of the Haskell state, and pass it to C and back. I'd probably do the former. -- Don