DeclarationDescriptors returned from type constructors

idea/src/org/jetbrains/jet/lang/resolve/ClassDescriptorResolver.java

@@ -70,6 +70,7 @@ public class ClassDescriptorResolver {
 
         descriptor.setTypeConstructor(
                 new TypeConstructor(
+                        descriptor,
                         AttributeResolver.INSTANCE.resolveAttributes(classElement.getModifierList()),
                         !open,
                         classElement.getName(),

idea/src/org/jetbrains/jet/lang/types/ClassDescriptorImpl.java

@@ -33,7 +33,7 @@ public class ClassDescriptorImpl extends DeclarationDescriptorImpl implements Cl
     public final ClassDescriptorImpl initialize(boolean sealed,
                                                 List<TypeParameterDescriptor> typeParameters,
                                                 Collection<? extends JetType> superclasses, JetScope memberDeclarations) {
-        this.typeConstructor = new TypeConstructor(getAttributes(), sealed, getName(), typeParameters, superclasses);
+        this.typeConstructor = new TypeConstructor(this, getAttributes(), sealed, getName(), typeParameters, superclasses);
         this.memberDeclarations = memberDeclarations;
         return this;
     }

idea/src/org/jetbrains/jet/lang/types/ErrorType.java

@@ -63,7 +63,7 @@ public class ErrorType {
     }
 
     private static JetType createErrorType(String debugMessage, JetScope memberScope) {
-        return new ErrorTypeImpl(new TypeConstructor(Collections.<Attribute>emptyList(), false, "[ERROR : " + debugMessage + "]", Collections.<TypeParameterDescriptor>emptyList(), Collections.<JetType>emptyList()), memberScope);
+        return new ErrorTypeImpl(new TypeConstructor(null, Collections.<Attribute>emptyList(), false, "[ERROR : " + debugMessage + "]", Collections.<TypeParameterDescriptor>emptyList(), Collections.<JetType>emptyList()), memberScope);
     }
 
     public static JetType createWrongVarianceErrorType(TypeProjection value) {

idea/src/org/jetbrains/jet/lang/types/TypeConstructor.java

@@ -1,5 +1,8 @@
 package org.jetbrains.jet.lang.types;
 
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
@@ -13,18 +16,30 @@ public class TypeConstructor extends AnnotatedImpl {
     private final String debugName;
     private final boolean sealed;
 
-    public TypeConstructor(List<Attribute> attributes, boolean sealed, String debugName, List<TypeParameterDescriptor> parameters, Collection<? extends JetType> supertypes) {
+    @Nullable
+    private final DeclarationDescriptor declarationDescriptor;
+
+    public TypeConstructor(
+            @Nullable DeclarationDescriptor declarationDescriptor,
+            @NotNull List<Attribute> attributes,
+            boolean sealed,
+            @NotNull String debugName,
+            @NotNull List<TypeParameterDescriptor> parameters,
+            @NotNull Collection<? extends JetType> supertypes) {
         super(attributes);
+        this.declarationDescriptor = declarationDescriptor;
         this.sealed = sealed;
         this.debugName = debugName;
         this.parameters = new ArrayList<TypeParameterDescriptor>(parameters);
         this.supertypes = supertypes;
     }
 
+    @NotNull
     public List<TypeParameterDescriptor> getParameters() {
         return parameters;
     }
 
+    @NotNull
     public Collection<? extends JetType> getSupertypes() {
         return supertypes;
     }
@@ -38,4 +53,8 @@ public class TypeConstructor extends AnnotatedImpl {
         return sealed;
     }
 
+    @Nullable
+    public DeclarationDescriptor getDeclarationDescriptor() {
+        return declarationDescriptor;
+    }
 }

idea/src/org/jetbrains/jet/lang/types/TypeParameterDescriptor.java

@@ -20,6 +20,7 @@ public class TypeParameterDescriptor extends DeclarationDescriptorImpl {
         this.upperBounds = upperBounds;
         // TODO: Should we actually pass the attributes on to the type constructor?
         this.typeConstructor = new TypeConstructor(
+                this,
                 attributes,
                 false,
                 "&" + name,

idea/src/org/jetbrains/jet/lang/types/TypeUtils.java

@@ -56,7 +56,7 @@ public class TypeUtils {
         }
 
         List<Attribute> noAttributes = Collections.<Attribute>emptyList();
-        TypeConstructor constructor = new TypeConstructor(noAttributes, false, debugName.toString(), Collections.<TypeParameterDescriptor>emptyList(), types);
+        TypeConstructor constructor = new TypeConstructor(null, noAttributes, false, debugName.toString(), Collections.<TypeParameterDescriptor>emptyList(), types);
         return new JetTypeImpl(
                 noAttributes,
                 constructor,