Implement continue for switch.

sdk/lib/_internal/compiler/implementation/resolution/members.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of resolution;
 
 abstract class TreeElements {
   Element get currentElement;
   Set<Node> get superUses;
 
@@ skipping 2697 matching lines @@
       String labelName = node.target.source.slowToString();
       LabelElement label = statementScope.lookupLabel(labelName);
       if (label == null) {
         error(node.target, MessageKind.UNBOUND_LABEL, {'labelName': labelName});
         return;
       }
       target = label.target;
       if (!target.statement.isValidContinueTarget()) {
         error(node.target, MessageKind.INVALID_CONTINUE);
       }
-      // TODO(lrn): Handle continues to switch cases.
-      if (target.statement is SwitchCase) {
-        unimplemented(node, "continue to switch case");
-      }
       label.setContinueTarget();
       mapping[node.target] = label;
     }
     mapping[node] = target;
   }
 
   registerImplicitInvocation(SourceString name, int arity) {
     Selector selector = new Selector.call(name, null, arity);
     world.registerDynamicInvocation(name, selector);
   }
@@ skipping 159 matching lines @@
           // It's only a warning if it shadows another label.
           existingElement = statementScope.lookupLabel(labelName);
           if (existingElement != null) {
             warning(label, MessageKind.DUPLICATE_LABEL,
                     {'labelName': labelName});
             warning(existingElement.label,
                     MessageKind.EXISTING_LABEL, {'labelName': labelName});
           }
         }
 
-        TargetElement targetElement =
-            new TargetElementX(switchCase,
-                               statementScope.nestingLevel,
-                               enclosingElement);
-        if (mapping[switchCase] != null) {
-          // TODO(ahe): Talk to Lasse about this.
-          mapping.remove(switchCase);
-        }
-        mapping[switchCase] = targetElement;
-
-        LabelElement labelElement =
-            new LabelElementX(label, labelName,
-                              targetElement, enclosingElement);
+        TargetElement targetElement = getOrCreateTargetElement(switchCase);
+        LabelElement labelElement = targetElement.addLabel(label, labelName);
         mapping[label] = labelElement;
         continueLabels[labelName] = labelElement;
       }
       cases = cases.tail;
       // Test that only the last case, if any, is a default case.
       if (switchCase.defaultKeyword != null && !cases.isEmpty) {
         error(switchCase, MessageKind.INVALID_CASE_DEFAULT);
       }
     }
 
@@ skipping 991 matching lines @@
     return e;
   }
 
   /// Assumed to be called by [resolveRedirectingFactory].
   Element visitReturn(Return node) {
     Node expression = node.expression;
     return finishConstructorReference(visit(expression),
                                       expression, expression);
   }
 }