anchor.diff:          });
         }
       catch (e) {
  -      request.response.writeln("Err");
  +      request.response.statusCode = 500;
         request.response.writeln(e);
         request.response.close();
       }
  
positive.code:     builder.add(buffer);
    }, onDone: () {
  
      //builder now contains
  
      String source = UTF8.decode(builder.toBytes());
      //request.response.writeln(source);
      //String source = sampleCodeWeb;
  
      //TODO(luke): replace this with something unforgable
  
      checkCache("%%COMPILE:" +source).then((String r) {
        if (r != null) {
          logging.info("Cache hit for compile");
          request.response.writeln(r);
          request.response.close();
          return r;
        } else {
          Stopwatch watch = new Stopwatch()..start();
  
                compiler.compile(source).then((CompilationResults results) {
  
  
                  if (results.hasOutput) {
                    int lineCount = source.split('\n').length;
                    int outputSize = (results.getOutput().length + 512) ~/ 1024;
                    int ms = watch.elapsedMilliseconds;
                    logging.info('Compiled ${lineCount} lines of Dart into '
                        '${outputSize}kb of JavaScript in ${ms}ms.');
  
                    String out = results.getOutput();
  
                    request.response.writeln(out);
                    pushCache("%%COMPILE:" + source, out);
                  }
  
                  request.response.close();
        });
      }
  
  
  
  
    });
    });
  }
  
  
negative.code:     handleCompilePost(request);
    } else {
      request.response.statusCode = 404;
      request.response.close();
    }
  }
  
  handleAnalyzePost(io.HttpRequest request) {
  