Error produced for missing var, final, const or type on field declarations.

lib/compiler/implementation/scanner/listener.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.
 
 final bool VERBOSE = false;
 
 /**
  * A parser event listener that does nothing except throw exceptions
  * on parser errors.
  */
@@ skipping 1509 matching lines @@
                           Token this.endToken,
                           Modifiers modifiers,
                           Element enclosing)
     : super(ElementKind.VARIABLE_LIST, modifiers, enclosing);
 
   VariableDefinitions parseNode(DiagnosticListener listener) {
     if (cachedNode != null) return cachedNode;
     cachedNode = parse(listener,
                        getCompilationUnit(),
                        (p) => p.parseVariablesDeclaration(beginToken));
+    if (!cachedNode.modifiers.isVar() &&
+        !cachedNode.modifiers.isFinal() &&
+        !cachedNode.modifiers.isConst() &&
+        cachedNode.type === null) {
+      listener.cancel('A field declaration must start with var, final, '
+                      'const, or a type annotation.',
+                      cachedNode);
+    }
     return cachedNode;
   }
 
   Token position() => beginToken; // findMyName doesn't work. I'm nameless.
 }
 
 class PartialTypedefElement extends TypedefElement {
   final Token token;
 
   PartialTypedefElement(SourceString name, Element enclosing, this.token)
@@ skipping 12 matching lines @@
 
 Node parse(DiagnosticListener diagnosticListener,
            CompilationUnitElement element,
            doParse(Parser parser)) {
   NodeListener listener = new NodeListener(diagnosticListener, element);
   doParse(new Parser(listener));
   Node node = listener.popNode();
   assert(listener.nodes.isEmpty());
   return node;
 }