LabelName stores label name

TODO: uncomment assertions in LabelName constructor

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

@@ -25,6 +25,7 @@ import org.jetbrains.jet.lang.descriptors.ClassifierDescriptor;
 import org.jetbrains.jet.lang.descriptors.DeclarationDescriptor;
 import org.jetbrains.jet.lang.descriptors.NamespaceDescriptor;
 import org.jetbrains.jet.lang.resolve.name.FqName;
+import org.jetbrains.jet.lang.resolve.name.LabelName;
 import org.jetbrains.jet.lang.resolve.scopes.receivers.ReceiverDescriptor;
 
 import java.util.Collection;
@@ -56,7 +57,7 @@ public class JavaClassMembersScope extends JavaClassOrPackageScope {
 
     @NotNull
     @Override
-    public Collection<DeclarationDescriptor> getDeclarationsByLabel(String labelName) {
+    public Collection<DeclarationDescriptor> getDeclarationsByLabel(LabelName labelName) {
         throw new UnsupportedOperationException(); // TODO
     }
 

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

@@ -18,6 +18,7 @@ package org.jetbrains.jet.lang.resolve;
 
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.jet.lang.descriptors.*;
+import org.jetbrains.jet.lang.resolve.name.LabelName;
 import org.jetbrains.jet.lang.resolve.scopes.JetScope;
 import org.jetbrains.jet.lang.resolve.scopes.receivers.ReceiverDescriptor;
 
@@ -91,7 +92,7 @@ public abstract class AbstractScopeAdapter implements JetScope {
 
     @NotNull
     @Override
-    public Collection<DeclarationDescriptor> getDeclarationsByLabel(String labelName) {
+    public Collection<DeclarationDescriptor> getDeclarationsByLabel(LabelName labelName) {
         return getWorkerScope().getDeclarationsByLabel(labelName);
     }
 

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

@@ -0,0 +1,68 @@
+/*
+ * 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 class LabelName {
+
+    @NotNull
+    private final String name;
+
+    public LabelName(@NotNull String name) {
+        if (name.startsWith("@")) {
+            // label may contain @, and may not contain
+            //throw new IllegalArgumentException("@ must be chopped: " + name);
+        }
+
+        if (name.length() == 0) {
+            // label can be empty
+            //throw new IllegalStateException("label cannot be empty");
+        }
+
+        this.name = name;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    @Override
+    public String toString() {
+        return name;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+
+        LabelName name1 = (LabelName) o;
+
+        if (!name.equals(name1.name)) return false;
+
+        return true;
+    }
+
+    @Override
+    public int hashCode() {
+        return name.hashCode();
+    }
+}

compiler/frontend/src/org/jetbrains/jet/lang/resolve/scopes/ChainedScope.java

@@ -19,6 +19,7 @@ package org.jetbrains.jet.lang.resolve.scopes;
 import com.google.common.collect.Sets;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.jet.lang.descriptors.*;
+import org.jetbrains.jet.lang.resolve.name.LabelName;
 import org.jetbrains.jet.lang.resolve.scopes.receivers.ReceiverDescriptor;
 
 import java.util.Collection;
@@ -134,7 +135,7 @@ public class ChainedScope implements JetScope {
 
     @NotNull
     @Override
-    public Collection<DeclarationDescriptor> getDeclarationsByLabel(String labelName) {
+    public Collection<DeclarationDescriptor> getDeclarationsByLabel(LabelName labelName) {
         for (JetScope jetScope : scopeChain) {
             Collection<DeclarationDescriptor> declarationsByLabel = jetScope.getDeclarationsByLabel(labelName);
             if (!declarationsByLabel.isEmpty()) return declarationsByLabel; // TODO : merge?

compiler/frontend/src/org/jetbrains/jet/lang/resolve/scopes/InnerClassesScopeWrapper.java

@@ -24,6 +24,7 @@ import org.jetbrains.jet.lang.descriptors.ClassDescriptor;
 import org.jetbrains.jet.lang.descriptors.ClassKind;
 import org.jetbrains.jet.lang.descriptors.ClassifierDescriptor;
 import org.jetbrains.jet.lang.descriptors.DeclarationDescriptor;
+import org.jetbrains.jet.lang.resolve.name.LabelName;
 import org.jetbrains.jet.lang.resolve.scopes.receivers.ReceiverDescriptor;
 
 import java.util.Collection;
@@ -58,7 +59,7 @@ public class InnerClassesScopeWrapper extends JetScopeImpl {
 
     @NotNull
     @Override
-    public Collection<DeclarationDescriptor> getDeclarationsByLabel(String labelName) {
+    public Collection<DeclarationDescriptor> getDeclarationsByLabel(LabelName labelName) {
         Collection<DeclarationDescriptor> declarationsByLabel = actualScope.getDeclarationsByLabel(labelName);
         return Collections2.filter(declarationsByLabel, new Predicate<DeclarationDescriptor>() {
             @Override

compiler/frontend/src/org/jetbrains/jet/lang/resolve/scopes/JetScope.java

@@ -19,6 +19,7 @@ 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.LabelName;
 import org.jetbrains.jet.lang.resolve.scopes.receivers.ReceiverDescriptor;
 
 import java.util.Collection;
@@ -67,7 +68,7 @@ public interface JetScope {
     DeclarationDescriptor getContainingDeclaration();
 
     @NotNull
-    Collection<DeclarationDescriptor> getDeclarationsByLabel(String labelName);
+    Collection<DeclarationDescriptor> getDeclarationsByLabel(LabelName labelName);
 
     /**
      * @param fieldName includes the "$"

compiler/frontend/src/org/jetbrains/jet/lang/resolve/scopes/JetScopeImpl.java

@@ -18,6 +18,7 @@ package org.jetbrains.jet.lang.resolve.scopes;
 
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.jet.lang.descriptors.*;
+import org.jetbrains.jet.lang.resolve.name.LabelName;
 import org.jetbrains.jet.lang.resolve.scopes.receivers.ReceiverDescriptor;
 
 import java.util.Collection;
@@ -75,7 +76,7 @@ public abstract class JetScopeImpl implements JetScope {
 
     @NotNull
     @Override
-    public Collection<DeclarationDescriptor> getDeclarationsByLabel(String labelName) {
+    public Collection<DeclarationDescriptor> getDeclarationsByLabel(LabelName labelName) {
         return Collections.emptyList();
     }
 

compiler/frontend/src/org/jetbrains/jet/lang/resolve/scopes/SubstitutingScope.java

@@ -21,6 +21,7 @@ import com.google.common.collect.Sets;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.jet.lang.descriptors.*;
+import org.jetbrains.jet.lang.resolve.name.LabelName;
 import org.jetbrains.jet.lang.resolve.scopes.receivers.ReceiverDescriptor;
 import org.jetbrains.jet.lang.types.TypeSubstitutor;
 
@@ -136,7 +137,7 @@ public class SubstitutingScope implements JetScope {
 
     @NotNull
     @Override
-    public Collection<DeclarationDescriptor> getDeclarationsByLabel(String labelName) {
+    public Collection<DeclarationDescriptor> getDeclarationsByLabel(LabelName labelName) {
         throw new UnsupportedOperationException(); // TODO
     }
 

compiler/frontend/src/org/jetbrains/jet/lang/resolve/scopes/WritableScopeImpl.java

@@ -21,6 +21,7 @@ import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.jet.lang.descriptors.*;
 import org.jetbrains.jet.lang.resolve.DescriptorUtils;
+import org.jetbrains.jet.lang.resolve.name.LabelName;
 import org.jetbrains.jet.lang.resolve.scopes.receivers.ReceiverDescriptor;
 import org.jetbrains.jet.lang.types.checker.JetTypeChecker;
 import org.jetbrains.jet.util.CommonSuppliers;
@@ -56,7 +57,7 @@ public class WritableScopeImpl extends WritableScopeWithImports {
     private Map<String, NamespaceDescriptor> namespaceAliases;
 
     @Nullable
-    private Map<String, List<DeclarationDescriptor>> labelsToDescriptors;
+    private Map<LabelName, List<DeclarationDescriptor>> labelsToDescriptors;
     
     @Nullable
     private Map<String, ClassDescriptor> objectDescriptors;
@@ -137,9 +138,9 @@ public class WritableScopeImpl extends WritableScopeWithImports {
     }
 
     @NotNull
-    private Map<String, List<DeclarationDescriptor>> getLabelsToDescriptors() {
+    private Map<LabelName, List<DeclarationDescriptor>> getLabelsToDescriptors() {
         if (labelsToDescriptors == null) {
-            labelsToDescriptors = new HashMap<String, List<DeclarationDescriptor>>();
+            labelsToDescriptors = new HashMap<LabelName, List<DeclarationDescriptor>>();
         }
         return labelsToDescriptors;
     }
@@ -154,11 +155,11 @@ public class WritableScopeImpl extends WritableScopeWithImports {
 
     @NotNull
     @Override
-    public Collection<DeclarationDescriptor> getDeclarationsByLabel(@NotNull String labelName) {
+    public Collection<DeclarationDescriptor> getDeclarationsByLabel(@NotNull LabelName labelName) {
         checkMayRead();
 
         Collection<DeclarationDescriptor> superResult = super.getDeclarationsByLabel(labelName);
-        Map<String, List<DeclarationDescriptor>> labelsToDescriptors = getLabelsToDescriptors();
+        Map<LabelName, List<DeclarationDescriptor>> labelsToDescriptors = getLabelsToDescriptors();
         List<DeclarationDescriptor> declarationDescriptors = labelsToDescriptors.get(labelName);
         if (declarationDescriptors == null) {
             return superResult;
@@ -173,9 +174,8 @@ public class WritableScopeImpl extends WritableScopeWithImports {
     public void addLabeledDeclaration(@NotNull DeclarationDescriptor descriptor) {
         checkMayWrite();
 
-        Map<String, List<DeclarationDescriptor>> labelsToDescriptors = getLabelsToDescriptors();
+        Map<LabelName, List<DeclarationDescriptor>> labelsToDescriptors = getLabelsToDescriptors();
-        String name = descriptor.getName();
+        LabelName name = new LabelName(descriptor.getName());
-        assert name != null;
         List<DeclarationDescriptor> declarationDescriptors = labelsToDescriptors.get(name);
         if (declarationDescriptors == null) {
             declarationDescriptors = new ArrayList<DeclarationDescriptor>();

compiler/frontend/src/org/jetbrains/jet/lang/resolve/scopes/WriteThroughScope.java

@@ -22,6 +22,7 @@ import com.google.common.collect.Sets;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.jet.lang.descriptors.*;
+import org.jetbrains.jet.lang.resolve.name.LabelName;
 import org.jetbrains.jet.lang.resolve.scopes.receivers.ReceiverDescriptor;
 
 import java.util.Collection;
@@ -49,7 +50,7 @@ public class WriteThroughScope extends WritableScopeWithImports {
 
     @Override
     @NotNull
-    public Collection<DeclarationDescriptor> getDeclarationsByLabel(String labelName) {
+    public Collection<DeclarationDescriptor> getDeclarationsByLabel(LabelName labelName) {
         checkMayRead();
 
         return writableWorker.getDeclarationsByLabel(labelName);

compiler/frontend/src/org/jetbrains/jet/lang/types/ErrorUtils.java

@@ -20,6 +20,7 @@ import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.jet.lang.descriptors.*;
 import org.jetbrains.jet.lang.descriptors.annotations.AnnotationDescriptor;
+import org.jetbrains.jet.lang.resolve.name.LabelName;
 import org.jetbrains.jet.lang.resolve.scopes.JetScope;
 import org.jetbrains.jet.lang.resolve.scopes.receivers.ReceiverDescriptor;
 import org.jetbrains.jet.lang.types.error.ErrorSimpleFunctionDescriptorImpl;
@@ -99,7 +100,7 @@ public class ErrorUtils {
 
         @NotNull
         @Override
-        public Collection<DeclarationDescriptor> getDeclarationsByLabel(String labelName) {
+        public Collection<DeclarationDescriptor> getDeclarationsByLabel(LabelName labelName) {
             return Collections.emptyList();
         }
 

compiler/frontend/src/org/jetbrains/jet/lang/types/expressions/BasicExpressionTypingVisitor.java

@@ -36,6 +36,7 @@ import org.jetbrains.jet.lang.resolve.calls.autocasts.DataFlowInfo;
 import org.jetbrains.jet.lang.resolve.calls.autocasts.DataFlowValueFactory;
 import org.jetbrains.jet.lang.resolve.constants.*;
 import org.jetbrains.jet.lang.resolve.constants.StringValue;
+import org.jetbrains.jet.lang.resolve.name.LabelName;
 import org.jetbrains.jet.lang.resolve.scopes.JetScope;
 import org.jetbrains.jet.lang.resolve.scopes.WritableScopeImpl;
 import org.jetbrains.jet.lang.resolve.scopes.receivers.ClassReceiver;
@@ -486,7 +487,8 @@ public class BasicExpressionTypingVisitor extends ExpressionTypingVisitor {
         ReceiverDescriptor thisReceiver = null;
         String labelName = expression.getLabelName();
         if (labelName != null) {
-            thisReceiver = context.labelResolver.resolveThisLabel(expression.getInstanceReference(), expression.getTargetLabel(), context, thisReceiver, labelName);
+            thisReceiver = context.labelResolver.resolveThisLabel(
+                    expression.getInstanceReference(), expression.getTargetLabel(), context, thisReceiver, new LabelName(labelName));
         }
         else {
             if (onlyClassReceivers) {
@@ -682,7 +684,7 @@ public class BasicExpressionTypingVisitor extends ExpressionTypingVisitor {
         if (JetTokens.LABELS.contains(operationSign.getReferencedNameElementType())) {
             String referencedName = operationSign.getReferencedName();
             referencedName = referencedName == null ? " <?>" : referencedName;
-            context.labelResolver.enterLabeledElement(referencedName.substring(1), baseExpression);
+            context.labelResolver.enterLabeledElement(new LabelName(referencedName.substring(1)), baseExpression);
             // TODO : Some processing for the label?
             JetType type = facade.getType(baseExpression, context, isStatement);
             context.labelResolver.exitLabeledElement(baseExpression);

compiler/frontend/src/org/jetbrains/jet/lang/types/expressions/LabelResolver.java

@@ -25,6 +25,7 @@ import org.jetbrains.jet.lang.descriptors.FunctionDescriptor;
 import org.jetbrains.jet.lang.psi.*;
 import org.jetbrains.jet.lang.resolve.BindingContext;
 import org.jetbrains.jet.lang.resolve.BindingContextUtils;
+import org.jetbrains.jet.lang.resolve.name.LabelName;
 import org.jetbrains.jet.lang.resolve.scopes.receivers.ReceiverDescriptor;
 
 import java.util.*;
@@ -37,11 +38,11 @@ import static org.jetbrains.jet.lang.resolve.BindingContext.*;
 */
 public class LabelResolver {
 
-    private final Map<String, Stack<JetElement>> labeledElements = new HashMap<String, Stack<JetElement>>();
+    private final Map<LabelName, Stack<JetElement>> labeledElements = new HashMap<LabelName, Stack<JetElement>>();
 
     public LabelResolver() {}
 
-    public void enterLabeledElement(@NotNull String labelName, @NotNull JetExpression labeledExpression) {
+    public void enterLabeledElement(@NotNull LabelName labelName, @NotNull JetExpression labeledExpression) {
         JetExpression deparenthesized = JetPsiUtil.deparenthesize(labeledExpression);
         if (deparenthesized != null) {
             Stack<JetElement> stack = labeledElements.get(labelName);
@@ -56,8 +57,8 @@ public class LabelResolver {
     public void exitLabeledElement(@NotNull JetExpression expression) {
         JetExpression deparenthesized = JetPsiUtil.deparenthesize(expression);
         // TODO : really suboptimal
-        for (Iterator<Map.Entry<String, Stack<JetElement>>> mapIter = labeledElements.entrySet().iterator(); mapIter.hasNext(); ) {
+        for (Iterator<Map.Entry<LabelName,Stack<JetElement>>> mapIter = labeledElements.entrySet().iterator(); mapIter.hasNext(); ) {
-            Map.Entry<String, Stack<JetElement>> entry = mapIter.next();
+            Map.Entry<LabelName, Stack<JetElement>> entry = mapIter.next();
             Stack<JetElement> stack = entry.getValue();
             for (Iterator<JetElement> stackIter = stack.iterator(); stackIter.hasNext(); ) {
                 JetElement recorded = stackIter.next();
@@ -72,7 +73,7 @@ public class LabelResolver {
     }
 
     @Nullable
-    private JetElement resolveControlLabel(@NotNull String labelName, @NotNull JetSimpleNameExpression labelExpression, boolean reportUnresolved, ExpressionTypingContext context) {
+    private JetElement resolveControlLabel(@NotNull LabelName labelName, @NotNull JetSimpleNameExpression labelExpression, boolean reportUnresolved, ExpressionTypingContext context) {
         Collection<DeclarationDescriptor> declarationsByLabel = context.scope.getDeclarationsByLabel(labelName);
         int size = declarationsByLabel.size();
 
@@ -99,14 +100,13 @@ public class LabelResolver {
     public JetElement resolveLabel(JetLabelQualifiedExpression expression, ExpressionTypingContext context) {
         JetSimpleNameExpression labelElement = expression.getTargetLabel();
         if (labelElement != null) {
-            String labelName = expression.getLabelName();
+            LabelName labelName = new LabelName(expression.getLabelName());
-            assert labelName != null;
             return resolveControlLabel(labelName, labelElement, true, context);
         }
         return null;
     }
 
-    private JetElement resolveNamedLabel(@NotNull String labelName, @NotNull JetSimpleNameExpression labelExpression, boolean reportUnresolved, ExpressionTypingContext context) {
+    private JetElement resolveNamedLabel(@NotNull LabelName labelName, @NotNull JetSimpleNameExpression labelExpression, boolean reportUnresolved, ExpressionTypingContext context) {
         Stack<JetElement> stack = labeledElements.get(labelName);
         if (stack == null || stack.isEmpty()) {
             if (reportUnresolved) {
@@ -123,7 +123,8 @@ public class LabelResolver {
         return result;
     }
 
-    public ReceiverDescriptor resolveThisLabel(JetReferenceExpression thisReference, JetSimpleNameExpression targetLabel, ExpressionTypingContext context, ReceiverDescriptor thisReceiver, String labelName) {
+    public ReceiverDescriptor resolveThisLabel(JetReferenceExpression thisReference, JetSimpleNameExpression targetLabel,
+            ExpressionTypingContext context, ReceiverDescriptor thisReceiver, LabelName labelName) {
         Collection<DeclarationDescriptor> declarationsByLabel = context.scope.getDeclarationsByLabel(labelName);
         int size = declarationsByLabel.size();
         assert targetLabel != null;