KT-3301 Inference with several supertypes fails

#KT-3301 fixed
2013-01-30 20:29:30 +04:00
parent 3c82e80745
commit ba9c455ea1
3 changed files with 46 additions and 0 deletions
@@ -33,6 +33,12 @@ public class ConstraintsUtil {
    public static Set<JetType> getValues(@Nullable TypeConstraints typeConstraints) {
        Set<JetType> values = Sets.newLinkedHashSet();
        if (typeConstraints != null && !typeConstraints.isEmpty()) {
+            if (typeConstraints.getExactBounds().size() == 1) {
+                if (verifyOneExactBound(typeConstraints)) {
+                    JetType exactBound = typeConstraints.getExactBounds().iterator().next();
+                    return Collections.singleton(exactBound);
+                }
+            }
            values.addAll(typeConstraints.getExactBounds());
            if (!typeConstraints.getLowerBounds().isEmpty()) {
                JetType superTypeOfLowerBounds = CommonSupertypes.commonSupertype(typeConstraints.getLowerBounds());
@@ -63,6 +69,21 @@ public class ConstraintsUtil {
        return values;
    }

+    private static boolean verifyOneExactBound(@NotNull TypeConstraints typeConstraints) {
+        JetType exactBound = typeConstraints.getExactBounds().iterator().next();
+        for (JetType lowerBound : typeConstraints.getLowerBounds()) {
+            if (!JetTypeChecker.INSTANCE.isSubtypeOf(lowerBound, exactBound)) {
+                return false;
+            }
+        }
+        for (JetType upperBound : typeConstraints.getUpperBounds()) {
+            if (!JetTypeChecker.INSTANCE.isSubtypeOf(exactBound, upperBound)) {
+                return false;
+            }
+        }
+        return true;
+    }
+
    @Nullable
    public static JetType getValue(@Nullable TypeConstraints typeConstraints) {
        //todo all checks