Don't generate duplicate properties for properties that use less type variables

src/testproperties.icl

@@ -362,15 +362,23 @@ generateProperties :: ![PropertyVarInstantiation] ![NamedTestGenerator] !String
 generateProperties pvis generators fname doc =
 	[gen i fname doc.preconditions p config
 		\\ p <- doc.properties
-		, config <- configurations $ groupInstantiations $ pvis ++ docPropertyTestWith doc
+		, config <- configurationsForProperty p (pvis ++ docPropertyTestWith doc)
 		& i <- [1..]]
 where
-	groupInstantiations :: [PropertyVarInstantiation] -> [[(String,Type)]]
-	groupInstantiations pvis = groupBy ((==) `on` fst) $ sortBy ((<) `on` fst) [vi \\ PropertyVarInstantiation vi <- pvis]
+	configurationsForProperty :: !Property ![PropertyVarInstantiation] -> [[(String,Type)]]
+	configurationsForProperty (ForAll _ ts _) pvis =
+		case [vi \\ PropertyVarInstantiation vi=:(v,_) <- pvis | isMember v allvs] of
+			[]  -> [[]]
+			vis -> configurations $ groupInstantiations vis
+	where
+		allvs = concatMap (allVars o snd) ts
+
+		groupInstantiations :: [(String,Type)] -> [[(String,Type)]]
+		groupInstantiations pvis = groupBy ((==) `on` fst) $ sortBy ((<) `on` fst) pvis
 
-	configurations :: [[(String,Type)]] -> [[(String,Type)]]
-	configurations [vis:viss] = [[vi`:vis`] \\ vi` <- vis, vis` <- configurations viss]
-	configurations [] = [[]]
+		configurations :: [[(String,Type)]] -> [[(String,Type)]]
+		configurations [vis:viss] = [[vi`:vis`] \\ vi` <- vis, vis` <- configurations viss]
+		configurations [] = [[]]
 
 	gen :: !Int !String ![String] !Property ![(String,Type)] -> GeneratedProperty
 	gen i fname preconditions (ForAll name ts imp) vis =