Create a limit on the min/max function values that will be generated.

diff --git a/src/Tests/FunctionValues.hs b/src/Tests/FunctionValues.hs
index 3dc38a49764507d0f66e9b00eebb6c4e0d82d564..3694f03c5ba0aa6aa5c56df85b90eddb321a1939 100644 (file)
--- a/src/Tests/FunctionValues.hs
+++ b/src/Tests/FunctionValues.hs
@@ -8,35 +8,48 @@ import Assertions
 import Examples
 import FunctionValues
 
+-- | We perform addition with the function values contained in a
+--   FunctionValues object. If we choose random doubles near the machine
+--   min/max, we risk overflowing or underflowing the 'Double'. This
+--   places a reasonably safe limit on the maximum size of our generated
+--   'Double' members.
+max_double :: Double
+max_double = 10000.0
+
+-- | See 'max_double'.
+min_double :: Double
+min_double = (-1) * max_double
+
+
 instance Arbitrary FunctionValues where
     arbitrary = do
-      front'  <- arbitrary :: Gen Double
-      back'   <- arbitrary :: Gen Double
-      left'   <- arbitrary :: Gen Double
-      right'  <- arbitrary :: Gen Double
-      top'    <- arbitrary :: Gen Double
-      down'   <- arbitrary :: Gen Double
-      front_left' <- arbitrary :: Gen Double
-      front_right' <- arbitrary :: Gen Double
-      front_top' <- arbitrary :: Gen Double
-      front_down' <- arbitrary :: Gen Double
-      back_left' <- arbitrary :: Gen Double
-      back_right' <- arbitrary :: Gen Double
-      back_top' <- arbitrary :: Gen Double
-      back_down' <- arbitrary :: Gen Double
-      left_top' <- arbitrary :: Gen Double
-      left_down' <- arbitrary :: Gen Double
-      right_top' <- arbitrary :: Gen Double
-      right_down' <- arbitrary :: Gen Double
-      front_left_top' <- arbitrary :: Gen Double
-      front_left_down' <- arbitrary :: Gen Double
-      front_right_top' <- arbitrary :: Gen Double
-      front_right_down' <- arbitrary :: Gen Double
-      back_left_top' <- arbitrary :: Gen Double
-      back_left_down' <- arbitrary :: Gen Double
-      back_right_top' <- arbitrary :: Gen Double
-      back_right_down' <- arbitrary :: Gen Double
-      interior' <- arbitrary :: Gen Double
+      front'  <- choose (min_double, max_double)
+      back'   <- choose (min_double, max_double)
+      left'   <- choose (min_double, max_double)
+      right'  <- choose (min_double, max_double)
+      top'    <- choose (min_double, max_double)
+      down'   <- choose (min_double, max_double)
+      front_left' <- choose (min_double, max_double)
+      front_right' <- choose (min_double, max_double)
+      front_top' <- choose (min_double, max_double)
+      front_down' <- choose (min_double, max_double)
+      back_left' <- choose (min_double, max_double)
+      back_right' <- choose (min_double, max_double)
+      back_top' <- choose (min_double, max_double)
+      back_down' <- choose (min_double, max_double)
+      left_top' <- choose (min_double, max_double)
+      left_down' <- choose (min_double, max_double)
+      right_top' <- choose (min_double, max_double)
+      right_down' <- choose (min_double, max_double)
+      front_left_top' <- choose (min_double, max_double)
+      front_left_down' <- choose (min_double, max_double)
+      front_right_top' <- choose (min_double, max_double)
+      front_right_down' <- choose (min_double, max_double)
+      back_left_top' <- choose (min_double, max_double)
+      back_left_down' <- choose (min_double, max_double)
+      back_right_top' <- choose (min_double, max_double)
+      back_right_down' <- choose (min_double, max_double)
+      interior' <- choose (min_double, max_double)
 
       return empty_values { front = front',
                             back  = back',