horse.hs

chooseHorse :: (RandomGen g) => g -> (Horse, g)
chooseHorse gen =
  let
    (rand, nextGen) =
      random gen :: (Float, g)

    -- Just choose any horse for the moment
    horse =
      horses !! 0
  in
  (horse, nextGen)
  
{-
    • Couldn't match type ‘g’ with ‘g1’
      ‘g’ is a rigid type variable bound by
        the type signature for:
          chooseHorse :: forall g. RandomGen g => g -> (Horse, g)
        at src/GrandNational.hs:20:16
      ‘g1’ is a rigid type variable bound by
        an expression type signature:
          forall g1. (Float, g1)
        at src/GrandNational.hs:24:21
      Expected type: (Float, g1)
        Actual type: (Float, g)
    • In the expression: random gen :: (Float, g)
      In a pattern binding: (rand, nextGen) = random gen :: (Float, g)
      In the expression:
        let
          (rand, nextGen) = random gen :: (Float, g)
          horse = horses !! 0
        in (horse, nextGen)
    • Relevant bindings include
        gen :: g (bound at src/GrandNational.hs:21:13)
        chooseHorse :: g -> (Horse, g) (bound at src/GrandNational.hs:21:1)
-}