diff --git a/core/descriptors/src/org/jetbrains/jet/lang/resolve/scopes/SubstitutingScope.java b/core/descriptors/src/org/jetbrains/jet/lang/resolve/scopes/SubstitutingScope.java
deleted file mode 100644
index e09b2c66fe2..00000000000
--- a/core/descriptors/src/org/jetbrains/jet/lang/resolve/scopes/SubstitutingScope.java
+++ /dev/null
@@ -1,155 +0,0 @@
-/*
- * Copyright 2010-2013 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.scopes;
-
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
-import org.jetbrains.jet.lang.descriptors.*;
-import org.jetbrains.jet.lang.resolve.name.Name;
-import org.jetbrains.jet.lang.types.TypeSubstitutor;
-import org.jetbrains.jet.utils.Printer;
-import org.jetbrains.jet.utils.UtilsPackage;
-
-import java.util.*;
-
-public class SubstitutingScope implements JetScope {
-
-    private final JetScope workerScope;
-    private final TypeSubstitutor substitutor;
-
-    private Map<DeclarationDescriptor, DeclarationDescriptor> substitutedDescriptors = null;
-    private Collection<DeclarationDescriptor> allDescriptors = null;
-
-    public SubstitutingScope(JetScope workerScope, @NotNull TypeSubstitutor substitutor) {
-        this.workerScope = workerScope;
-        this.substitutor = substitutor;
-    }
-
-    @Nullable
-    private <D extends DeclarationDescriptor> D substitute(@Nullable D descriptor) {
-        if (descriptor == null) return null;
-        if (substitutor.isEmpty()) return descriptor;
-
-        if (substitutedDescriptors == null) {
-            substitutedDescriptors = new HashMap<DeclarationDescriptor, DeclarationDescriptor>();
-        }
-
-        DeclarationDescriptor substituted = substitutedDescriptors.get(descriptor);
-        if (substituted == null && !substitutedDescriptors.containsKey(descriptor)) {
-            substituted = descriptor.substitute(substitutor);
-
-            //noinspection ConstantConditions
-            substitutedDescriptors.put(descriptor, substituted);
-        }
-
-        //noinspection unchecked
-        return (D) substituted;
-    }
-
-    @NotNull
-    private <D extends DeclarationDescriptor> Collection<D> substitute(@NotNull Collection<D> descriptors) {
-        if (substitutor.isEmpty()) return descriptors;
-        if (descriptors.isEmpty()) return descriptors;
-
-        Set<D> result = UtilsPackage.newHashSetWithExpectedSize(descriptors.size());
-        for (D descriptor : descriptors) {
-            D substitute = substitute(descriptor);
-            if (substitute != null) {
-                result.add(substitute);
-            }
-        }
-
-        return result;
-    }
-
-    @NotNull
-    @Override
-    public Collection<VariableDescriptor> getProperties(@NotNull Name name) {
-        return substitute(workerScope.getProperties(name));
-    }
-
-    @Override
-    public VariableDescriptor getLocalVariable(@NotNull Name name) {
-        return substitute(workerScope.getLocalVariable(name));
-    }
-
-    @Override
-    public ClassifierDescriptor getClassifier(@NotNull Name name) {
-        return substitute(workerScope.getClassifier(name));
-    }
-
-    @NotNull
-    @Override
-    public Collection<FunctionDescriptor> getFunctions(@NotNull Name name) {
-        return substitute(workerScope.getFunctions(name));
-    }
-
-    @Override
-    public PackageViewDescriptor getPackage(@NotNull Name name) {
-        return workerScope.getPackage(name);
-    }
-
-    @NotNull
-    @Override
-    public List<ReceiverParameterDescriptor> getImplicitReceiversHierarchy() {
-        throw new UnsupportedOperationException(); // TODO
-    }
-
-    @NotNull
-    @Override
-    public DeclarationDescriptor getContainingDeclaration() {
-        return workerScope.getContainingDeclaration();
-    }
-
-    @NotNull
-    @Override
-    public Collection<DeclarationDescriptor> getDeclarationsByLabel(@NotNull Name labelName) {
-        throw new UnsupportedOperationException(); // TODO
-    }
-
-    @NotNull
-    @Override
-    public Collection<DeclarationDescriptor> getAllDescriptors() {
-        if (allDescriptors == null) {
-            allDescriptors = substitute(workerScope.getAllDescriptors());
-        }
-        return allDescriptors;
-    }
-
-    @NotNull
-    @Override
-    public Collection<DeclarationDescriptor> getOwnDeclaredDescriptors() {
-        return substitute(workerScope.getOwnDeclaredDescriptors());
-    }
-
-    @Override
-    public void printScopeStructure(@NotNull Printer p) {
-        p.println(getClass().getSimpleName(), " {");
-        p.pushIndent();
-
-        p.println("substitutor = ");
-        p.pushIndent();
-        p.println(substitutor);
-        p.popIndent();
-
-        p.print("workerScope = ");
-        workerScope.printScopeStructure(p.withholdIndentOnce());
-
-        p.popIndent();
-        p.println("}");
-    }
-}
diff --git a/core/descriptors/src/org/jetbrains/jet/lang/resolve/scopes/SubstitutingScope.kt b/core/descriptors/src/org/jetbrains/jet/lang/resolve/scopes/SubstitutingScope.kt
new file mode 100644
index 00000000000..8e6fb62009f
--- /dev/null
+++ b/core/descriptors/src/org/jetbrains/jet/lang/resolve/scopes/SubstitutingScope.kt
@@ -0,0 +1,113 @@
+/*
+ * Copyright 2010-2014 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.scopes
+
+import org.jetbrains.jet.lang.descriptors.*
+import org.jetbrains.jet.lang.resolve.name.Name
+import org.jetbrains.jet.lang.types.TypeSubstitutor
+import org.jetbrains.jet.utils.Printer
+import org.jetbrains.jet.utils.*
+
+import java.util.*
+import kotlin.Map
+import kotlin.Collection
+import kotlin.List
+
+public class SubstitutingScope(private val workerScope: JetScope, private val substitutor: TypeSubstitutor) : JetScope {
+
+    private var substitutedDescriptors: MutableMap<DeclarationDescriptor, DeclarationDescriptor?>? = null
+    private var allDescriptors: Collection<DeclarationDescriptor>? = null
+
+    private fun <D : DeclarationDescriptor> substitute(descriptor: D?): D? {
+        if (descriptor == null) return null
+        if (substitutor.isEmpty()) return descriptor
+
+        if (substitutedDescriptors == null) {
+            substitutedDescriptors = HashMap<DeclarationDescriptor, DeclarationDescriptor>()
+        }
+
+        var substituted: DeclarationDescriptor? = substitutedDescriptors!!.get(descriptor)
+        if (substituted == null && !substitutedDescriptors!!.containsKey(descriptor)) {
+            substituted = descriptor.substitute(substitutor)
+
+            substitutedDescriptors!!.put(descriptor, substituted)
+        }
+
+        [suppress("UNCHECKED_CAST")]
+        return substituted as D?
+    }
+
+    private fun <D : DeclarationDescriptor> substitute(descriptors: Collection<D>): Collection<D> {
+        if (substitutor.isEmpty()) return descriptors
+        if (descriptors.isEmpty()) return descriptors
+
+        val result = newHashSetWithExpectedSize<D>(descriptors.size())
+        for (descriptor in descriptors) {
+            val substitute = substitute(descriptor)
+            if (substitute != null) {
+                result.add(substitute)
+            }
+        }
+
+        return result
+    }
+
+    override fun getProperties(name: Name) = substitute(workerScope.getProperties(name))
+
+    override fun getLocalVariable(name: Name) = substitute(workerScope.getLocalVariable(name))
+
+    override fun getClassifier(name: Name) = substitute(workerScope.getClassifier(name))
+
+    override fun getFunctions(name: Name) = substitute(workerScope.getFunctions(name))
+
+    override fun getPackage(name: Name) = workerScope.getPackage(name)
+
+    override fun getImplicitReceiversHierarchy(): List<ReceiverParameterDescriptor> {
+        throw UnsupportedOperationException() // TODO
+    }
+
+    override fun getContainingDeclaration() = workerScope.getContainingDeclaration()
+
+    override fun getDeclarationsByLabel(labelName: Name): Collection<DeclarationDescriptor> {
+        throw UnsupportedOperationException() // TODO
+    }
+
+    override fun getAllDescriptors(): Collection<DeclarationDescriptor> {
+        if (allDescriptors == null) {
+            allDescriptors = substitute(workerScope.getAllDescriptors())
+        }
+        return allDescriptors!!
+    }
+
+    override fun getOwnDeclaredDescriptors() = substitute(workerScope.getOwnDeclaredDescriptors())
+
+    override fun printScopeStructure(p: Printer) {
+        p.println(javaClass.getSimpleName(), " {")
+        p.pushIndent()
+
+        p.println("substitutor = ")
+        p.pushIndent()
+        p.println(substitutor)
+        p.popIndent()
+
+        p.print("workerScope = ")
+        workerScope.printScopeStructure(p.withholdIndentOnce())
+
+        p.popIndent()
+        p.println("}")
+    }
+}