Accept more labels per switch case.

lib/compiler/implementation/tree/unparser.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.
 
 class Unparser implements Visitor {
   StringBuffer sb;
   final bool printDebugInfo;
 
   Unparser([this.printDebugInfo = false]);
 
@@ skipping 329 matching lines @@
 
   visitSwitchStatement(SwitchStatement node) {
     add(node.switchKeyword.value);
     sb.add(' ');
     visit(node.parenthesizedExpression);
     sb.add(' ');
     visit(node.cases);
   }
 
   visitSwitchCase(SwitchCase node) {
-    if (node.label !== null) {
-      visit(node.label);
-      sb.add(': ');
+    Link<Label> labels = node.labels.nodes;
+    Link<CaseMatch> cases = node.cases.nodes;
+    // Interleave labels and cases in their original order.
+    while (!labels.isEmpty()) {
+      Label label = labels.head;
+      while (!cases.isEmpty()) {
+        CaseMatch match = cases.head;
+        if (match.colonToken.charOffset < label.colonToken.charOffset) {
+          visit(match);
+          cases = cases.tail;
+        } else {
+          break;
+        }
+      }
+      visit(label);
+      labels = labels.tail;
     }
-    for (Expression expression in node.expressions) {
-      sb.add('case ');
-      visit(expression);
-      sb.add(': ');
+    while (!cases.isEmpty()) {
+      visit(cases.head);
+      cases = cases.tail;
     }
     if (node.isDefaultCase) {
       sb.add('default:');
     }
     visit(node.statements);
   }
 
   visitScriptTag(ScriptTag node) {
     add(node.beginToken.value);
     visit(node.tag);
@@ skipping 14 matching lines @@
     visit(node.tryBlock);
     visit(node.catchBlocks);
     if (node.finallyKeyword !== null) {
       sb.add(' ');
       add(node.finallyKeyword.value);
       sb.add(' ');
       visit(node.finallyBlock);
     }
   }
 
+  visitCaseMatch(CaseMatch node) {
+    add(node.caseKeyword.value);
+    sb.add(" ");
+    visit(node.expression);
+    add(node.colonToken.value);
+  }
+
   visitCatchBlock(CatchBlock node) {
     add(node.catchKeyword.value);
     sb.add(' ');
     visit(node.formals);
     sb.add(' ');
     visit(node.block);
   }
 
   visitTypedef(Typedef node) {
     add(node.typedefKeyword.value);
     sb.add(' ');
     if (node.returnType !== null) {
       visit(node.returnType);
       sb.add(' ');
     }
     visit(node.name);
     if (node.typeParameters !== null) {
       visit(node.typeParameters);
     }
     visit(node.formals);
     add(node.endToken.value);
   }
 }