[Haskell] threading mutable state through callbacks

[Marcin 'Qrczak' Kowalczyk]

Jules Bean <jules at jellybean.co.uk> writes:

> Unless its possible to arrange haskell FFI bindings to have types in
> MonadIO rather than IO...

MonadIO is a class, not a type. Anyway, it's conceptually impossible
to wrap a computation of an arbitrary monad in the MonadIO class into
IO. It's not a technical difficulty, it just does not make sense.
It's similar to asking for a non-trivial function of type
Monad m => m a -> a. Unless you mean something else.

-- 
   __("<         Marcin Kowalczyk
   \__/       qrczak at knm.org.pl
    ^^     http://qrnik.knm.org.pl/~qrczak/