Implement parsing and resolving of type-variables.

frog/leg/ssa/builder.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 Interceptors {
   Compiler compiler;
   Interceptors(Compiler this.compiler);
 
   SourceString mapOperatorToMethodName(Operator op) {
     String name = op.source.stringValue;
@@ skipping 2482 matching lines @@
   }
 
   visitCatchBlock(CatchBlock node) {
     visit(node.block);
   }
 
   visitTypedef(Typedef node) {
     compiler.unimplemented('SsaBuilder.visitTypedef', node: node);
   }
 
+  visitTypeVariable(TypeVariable node) {
+    compiler.unimplemented('SsaBuilder.visitTypeVariable', node: node);
+  }
+
   generateUnimplemented(String reason, [bool isExpression = false]) {
     DartString string = new DartString.literal(reason);
     HInstruction message = graph.addConstantString(string);
 
     // Normally, we would call [close] here. However, then we hit
     // another unimplemented feature: aborting loop body. Simply
     // calling [add] does not work as it asserts that the instruction
     // isn't a control flow instruction. So we inline parts of [add].
     current.addAfter(current.last, new HThrow(message));
     if (isExpression) {
       stack.add(graph.addConstantNull());
     }
   }
 
   /** HACK HACK HACK */
   void hackAroundPossiblyAbortingBody(Node body) {
     stack.add(graph.addConstantBool(true));
     buildBody() {
       // TODO(lrn): Make sure to take continue into account.
       visit(body);
       if (isAborted()) {
         compiler.reportWarning(body, "aborting loop body");
       }
     }
     handleIf(buildBody, null);
   }
 }