The Par monad from the Control.Monad.Par package is used to speed up pure functions using parallel threads. Information flow is guided by variables called IVar. We can put values to IVar in parallel or get values from it.
Import the Par monad as follows:
import Control.Monad.Par
Run a computation in parallel, and perform some interesting function such as counting the number of digits and printing it out.
main = print $ length $ show $ runPar mypar
Define an I/O type action as follows:
mypar = do v1 <- new :: Par (IVar Integer) v2 <- new :: Par (IVar Integer) fork $ put v1 task1 fork $ put v2 task2 v1' <- get v1 v2' <- get v2 return (v1' + v2')
Perform a time-consuming task as follows:
task1 = 8^8^8
Perform another time-consuming task as follows:
task2 = 8^8^7
Compile the code with the
threadedandrtsoptsflags enabled, using the...