[Haskell-cafe] IO in HApps handler ?

Tim Newsham newsham at lava.net
Sun Aug 19 22:50:47 EDT 2007


> Subject: IO in HApps handler ?
> I am trying to add a handler that would run an external command in
> HApps 0.8.8, and I got a type issue I do not know how to get around..
>
> can we have IO in a handler ?

http://www.haskell.org/haskellwiki/HAppS_tutorial#Application

   "The MACID monad lets you update your state and *schedule*
    side-effects.  To be clear, MACID is not in the IO monad
    so you cannot execute side effects, you can only schedule
    them. The framework takes care of making sure they are
    executed at-least-once (if they can be completed by a
    deadline you specify)."

I don't know the specifics.

Tim Newsham
http://www.thenewsh.com/~newsham/


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