Add another test. Qualify KdTree import.

KdTreeTest.hs

@@ -2,28 +2,34 @@
 
 module Main where
 
+import Data.Maybe
 import qualified Data.List as L
 
 import Test.QuickCheck
 import Test.QuickCheck.All
 
-import Data.Trees.KdTree
+import qualified Data.Trees.KdTree as Kd
 
-prop_invariant :: [Point3d] -> Bool
-prop_invariant points = invariant' . fromList $ points
+prop_invariant :: [Kd.Point3d] -> Bool
+prop_invariant points = Kd.invariant' . Kd.fromList $ points
 
-prop_samePoints :: [Point3d] -> Bool
-prop_samePoints points = L.sort points == (L.sort . toList . fromList $ points)
+prop_samePoints :: [Kd.Point3d] -> Bool
+prop_samePoints points = L.sort points == (L.sort . Kd.toList . Kd.fromList $ points)
 
-prop_nearestNeighbor :: [Point3d] -> Point3d -> Bool
+prop_nearestNeighbor :: [Kd.Point3d] -> Kd.Point3d -> Bool
 prop_nearestNeighbor points probe =
-    nearestNeighbor tree probe == bruteNearestNeighbor points probe
-    where tree = fromList points
+    Kd.nearestNeighbor tree probe == bruteNearestNeighbor points probe
+    where tree = Kd.fromList points
 
-bruteNearestNeighbor :: [Point3d] -> Point3d -> Maybe Point3d
+prop_pointsAreClosestToThemselves :: [Kd.Point3d] -> Bool
+prop_pointsAreClosestToThemselves points =
+    map Just points == map (Kd.nearestNeighbor tree) points
+    where tree = Kd.fromList points
+
+bruteNearestNeighbor :: [Kd.Point3d] -> Kd.Point3d -> Maybe Kd.Point3d
 bruteNearestNeighbor [] _ = Nothing
 bruteNearestNeighbor points probe =
-    Just . head . L.sortBy (compareDistance probe) $ points
+    Just . head . L.sortBy (Kd.compareDistance probe) $ points
 
 main = $quickCheckAll