On Sat, Feb 5, 2011 at 10:46, wren ng thornton <w...@freegeek.org> wrote:
> Sometimes I need those threads to do some IO like printing logging info. Logging is easy, especially if you don't mind a performance hit. Create an STM.TChan and throw each log message on it. Have a separate forkIO'ed process that reads off log messages and prints them. The model one step up is to generalize the logger so it forwards log messages to handlers. This way you can do logging to stdout, binary serialized logging to disk, logging to memory ring buffers, logging to databases and so on. This generalized model is used a lot in Erlang. The price however, is that you may be running into a bottleneck upon entering messages on the TChan because sadly I can't remember if it is asynchronous or synchronous when you add messages to it. It won't work for general IO either (Though perhaps it is a Writer monad). -- J. _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
