On 15/06/2012 13:52, Twan van Laarhoven wrote:
On 08/06/12 10:37, Simon Marlow wrote:
I'd like to add a higher-level concurrency API to the base package.
How does this async package differ from monad-par, from a user's perspective? It seems that the latter is intended for pure computations and the implementation is more heavy weight. But it can be used for IO as well.
monad-par is for pure deterministic parallelism only, since it is based around runPar :: Par a -> a So I'm slightly confused by your comment that it can be used for IO as well - what do you mean exactly? I'd say monad-par is much more lightweight than async. Perhaps not in terms of the amount of code in the library, but the overhead of 'fork' in monad-par is much less than the overhead of 'async'. Incidentally, the IVar in monad-par is what I would call a "future" (in reference to the other suggestion that we use "Future" instead of "Async").
The difference in API is essentially only that async lives in the IO monad, whereas monad-par has its own Par monad.
Not being in IO is a pretty big difference :)
Could and/or should one be implemented in terms of the other?
We could implement monad-par in terms of Async, but I doubt it would make a lot of difference. The reverse is obviously not possible. Cheers, Simon