[Modified isCongruence and eqIsCongruence.
Nils Anders Danielsson <nad@cs.chalmers.se>**20050531204158
 * Removed need for Arbitrary instance by requiring explicit generator
   instead.
 * Moved test of (/=)-style function to isCongruence.
] {
hunk ./Test/ChasingBottoms/Nat/Tests.hs 75
-prop_Nat_Eq_congruence = eqIsCongruence arbitrary equalTo notEqualTo
+prop_Nat_Eq_congruence =
+  eqIsCongruence arbitrary equalTo notEqualTo
+                 (arbitrary :: Gen (Nat -> Integer))
hunk ./Test/ChasingBottoms/TestUtilities.hs 163
-
--- | Tests for a congruence. 'Arbitrary' instance needed for
--- 'coarbitrary'.
+-- | Tests for a congruence. Also tests that the negated relation is
+-- the negation of the relation.
hunk ./Test/ChasingBottoms/TestUtilities.hs 167
-  :: (Show a, Arbitrary a)
+  :: (Show a, Eq b)
hunk ./Test/ChasingBottoms/TestUtilities.hs 176
+     -> (a -> a -> Bool)
+     -- ^ The negated relation.
+     -> Gen (a -> b)
+     -- ^ Generator for functions.
+     -> (b -> b -> Bool)
+     -- ^ Equality for function result type.
hunk ./Test/ChasingBottoms/TestUtilities.hs 183
-isCongruence element equalTo notEqualTo (===) =
-  isEquivalenceRelation element equalTo notEqualTo (===) ++ [cong]
+isCongruence element equalTo notEqualTo (===) (/==) function (.===) =
+  isEquivalenceRelation element equalTo notEqualTo (===)
+  ++ [cong, eq_neq1, eq_neq2]
hunk ./Test/ChasingBottoms/TestUtilities.hs 187
-  cong = forAll arbitrary $ \f ->
+  cong = forAll function $ \f ->
hunk ./Test/ChasingBottoms/TestUtilities.hs 189
-             f x == (f y :: Integer)
+             f x .=== f y
+  eq_neq1 = forAll (pair element equalTo) $ \(x, y) ->
+              x === y && not (x /== y)
+  eq_neq2 = forAll (pair element notEqualTo) $ \(x, y) ->
+              not (x === y) && x /== y
hunk ./Test/ChasingBottoms/TestUtilities.hs 195
--- | Test that an 'Eq' instance is a congruence, and that '/=' is
--- the negation of '=='.
+-- | Test that an 'Eq' instance is a congruence.
hunk ./Test/ChasingBottoms/TestUtilities.hs 198
-  :: (Show a, Arbitrary a, Eq a)
+  :: (Show a, Eq a, Eq b)
hunk ./Test/ChasingBottoms/TestUtilities.hs 205
+     -> Gen (a -> b)
+     -- ^ Generator for functions.
hunk ./Test/ChasingBottoms/TestUtilities.hs 208
-eqIsCongruence element equalTo notEqualTo =
-  isCongruence element equalTo notEqualTo (==) ++ [eq_neq1, eq_neq2]
-  where
-  eq_neq1 = forAll (pair element equalTo) $ \(x, y) ->
-              x == y && not (x /= y)
-  eq_neq2 = forAll (pair element notEqualTo) $ \(x, y) ->
-              not (x == y) && x /= y
+eqIsCongruence element equalTo notEqualTo function =
+  isCongruence element equalTo notEqualTo (==) (/=) function (==)
}