Re: [Haskell-beginners] State Monad

Thank you very much! On 4/17/15 6:48 PM, Mike Meyer wrote:

On Fri, Apr 17, 2015 at 2:25 PM, Thomas Jakway mailto:tjakway@nyu.edu> wrote:

genThree listMax = do --highest index in the list let listMin = 0 :: Int --lowest index in the list generatedMin <- state randomR (listMin, listMax) return generatedMin

What you're missing is a $:

The only chagne to our genThree functions is making it "state $" instead of "state".

#!/usr/bin/env runhaskell

import System.Random import Control.Monad.State

genThree listMax = do --highest index in the list let listMin = 0 :: Int --lowest index in the list generatedMin <- state $ randomR (listMin, listMax) return generatedMin

main = do gen <- newStdGen print $ evalState (genThree 10) gen

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