Minor fixes

Chapter09/MainGame/Gameplay.fs

@@ -2,6 +2,11 @@
 
 open Microsoft.Xna.Framework
 
+
+// Converts an int<'M> to a float32<'M>
+let conv (x : int<'M>) =
+    LanguagePrimitives.Float32WithMeasure<'M>(float32 x)
+
 // Seconds
 [<Measure>]
 type s
@@ -20,7 +25,7 @@ type pix
 
 type City =
     { Name : string
-      Population : float32<h>
+      Population : int<h>
       Position : TypedVector2<m>
     }
 
@@ -213,7 +218,7 @@ let update (random : System.Random) (world : World) (dt : float32<s>) orders sta
                         0.0f
                     else
                         1.0f - distance/Explosion.Radius
-                let casualties = city.Population * relativeCasualties
+                let casualties = (conv city.Population) * relativeCasualties
                 max (survivors - casualties) 0.0f<h>
                 ) survivors
         )

Chapter09/MainGame/InputStateMachine.fs

@@ -8,13 +8,13 @@ type InputStateMachine<'InputState, 'Result> =
 // Used for selecting the controlling played in the "press start" screen.
 // Also used for pausing/resuming during gameplay.
 let waitReleased pressed released func =
-    let rec waitPressed =
+    let rec waitPressed() =
         fun (inputState) ->
             if pressed(inputState) then
                 let result = func inputState
                 waitReleased result
             else
-                waitPressed
+                waitPressed()
         |> Active
 
     and waitReleased result =
@@ -25,4 +25,4 @@ let waitReleased pressed released func =
                 waitReleased result
         |> Active
 
-    waitPressed
+    waitPressed()

Chapter09/MainGame/TypedVector.fs

@@ -30,7 +30,6 @@ module TypedVector =
         LanguagePrimitives.Float32WithMeasure<'M> (U.v.Length())
 
     let scale2 (k : float32<'K>, U : TypedVector2<'M>) : TypedVector2<'K 'M> =
-        let conv = LanguagePrimitives.Float32WithMeasure<'K 'M>
         let v = Vector2.Multiply(U.v, float32 k)
         TypedVector2(v)