FqName*.equalsTo, type safe unlike equals

compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/JavaDescriptorResolver.java

@@ -603,7 +603,7 @@ public class JavaDescriptorResolver implements DependencyClassByQualifiedNameRes
     private boolean isJavaLangObject(JetType type) {
         ClassifierDescriptor classifierDescriptor = type.getConstructor().getDeclarationDescriptor();
         return classifierDescriptor instanceof ClassDescriptor &&
-               DescriptorUtils.getFQName(classifierDescriptor).equals(JL_OBJECT.toUnsafe());
+               DescriptorUtils.getFQName(classifierDescriptor).equalsTo(JL_OBJECT);
     }
 
 

compiler/frontend/src/org/jetbrains/jet/lang/DefaultModuleConfiguration.java

@@ -59,7 +59,7 @@ public class DefaultModuleConfiguration implements ModuleConfiguration {
 
     @Override
     public void extendNamespaceScope(@NotNull BindingTrace trace, @NotNull NamespaceDescriptor namespaceDescriptor, @NotNull WritableScope namespaceMemberScope) {
-        if (DescriptorUtils.getFQName(namespaceDescriptor).equals(JetStandardClasses.STANDARD_CLASSES_FQNAME.toUnsafe())) {
+        if (DescriptorUtils.getFQName(namespaceDescriptor).equalsTo(JetStandardClasses.STANDARD_CLASSES_FQNAME)) {
             if (!extendBuiltins) {
                 namespaceMemberScope.importScope(JetStandardClasses.STANDARD_CLASSES);
             }

compiler/frontend/src/org/jetbrains/jet/lang/resolve/QualifiedExpressionResolver.java

@@ -392,7 +392,7 @@ public class QualifiedExpressionResolver {
             }
 
             if (namespaceDescriptor != null && classDescriptor != null) {
-                if (DescriptorUtils.getFQName(namespaceDescriptor).equals(DescriptorUtils.getFQName(classDescriptor))) {
+                if (DescriptorUtils.getFQName(namespaceDescriptor).equalsTo(DescriptorUtils.getFQName(classDescriptor))) {
                     trace.record(BindingContext.REFERENCE_TARGET, referenceExpression, classDescriptor);
                     trace.record(BindingContext.RESOLUTION_SCOPE, referenceExpression, resolutionScope);
                     checkVisibility(classDescriptor, trace, referenceExpression, scopeToCheckVisibility);

compiler/frontend/src/org/jetbrains/jet/lang/resolve/name/FqName.java

@@ -25,7 +25,7 @@ import java.util.List;
 /**
  * @author Stepan Koltsov
  */
-public class FqName {
+public class FqName extends FqNameBase {
 
     public static final FqName ROOT = new FqName("");
 

compiler/frontend/src/org/jetbrains/jet/lang/resolve/name/FqNameBase.java

@@ -0,0 +1,59 @@
+/*
+ * Copyright 2010-2012 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.jet.lang.resolve.name;
+
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * @author Stepan Koltsov
+ */
+public abstract class FqNameBase {
+
+    protected FqNameBase() {
+        if (!(this instanceof FqName || this instanceof FqNameUnsafe)) {
+            throw new AssertionError("do not use this class directly");
+        }
+    }
+
+    @NotNull
+    protected abstract String getFqName();
+
+    @NotNull
+    private FqNameUnsafe toFqNameUnsafe() {
+        if (this instanceof FqName) {
+            return ((FqName) this).toUnsafe();
+        }
+        else if (this instanceof FqNameUnsafe) {
+            return ((FqNameUnsafe) this);
+        }
+        else {
+            throw new AssertionError();
+        }
+    }
+
+    public final boolean equalsTo(@NotNull FqName that) {
+        return equalsTo(that.toUnsafe());
+    }
+
+    public final boolean equalsTo(@NotNull FqNameUnsafe that) {
+        return toFqNameUnsafe().equals(that);
+    }
+
+    public final boolean equalsTo(@NotNull String that) {
+        return getFqName().equals(that);
+    }
+}

compiler/frontend/src/org/jetbrains/jet/lang/resolve/name/FqNameUnsafe.java

@@ -27,7 +27,7 @@ import java.util.List;
  *
  * @author Stepan Koltsov
  */
-public class FqNameUnsafe {
+public class FqNameUnsafe extends FqNameBase {
 
     public static final Name ROOT_NAME = Name.special("<root>");
 

compiler/frontend/src/org/jetbrains/jet/resolve/DescriptorRenderer.java

@@ -274,7 +274,7 @@ public class DescriptorRenderer implements Renderer<DeclarationDescriptor> {
         final DeclarationDescriptor containingDeclaration = declarationDescriptor.getContainingDeclaration();
         if (containingDeclaration != null) {
             FqNameUnsafe fqName = DescriptorUtils.getFQName(containingDeclaration);
-            stringBuilder.append(FqName.ROOT.toUnsafe().equals(fqName) ? "root package" : escape(fqName.getFqName()));
+            stringBuilder.append(FqName.ROOT.equalsTo(fqName) ? "root package" : escape(fqName.getFqName()));
         }
     }
 

idea/src/org/jetbrains/jet/plugin/highlighter/IdeErrorMessages.java

@@ -222,7 +222,7 @@ public class IdeErrorMessages {
                 DeclarationDescriptor containingDeclaration = funDescriptor.getContainingDeclaration();
                 if (containingDeclaration != null) {
                     FqNameUnsafe fqName = DescriptorUtils.getFQName(containingDeclaration);
-                    stringBuilder.append(FqName.ROOT.toUnsafe().equals(fqName) ? "root package" : fqName.getFqName());
+                    stringBuilder.append(FqName.ROOT.equalsTo(fqName) ? "root package" : fqName.getFqName());
                 }
                 stringBuilder.append("</li>");
             }