anchor.diff:  import 'dart:async';
   import 'dart:collection' show Queue, LinkedHashMap;
   import 'dart:io';
  +import 'dart:math' as math;
   import 'dart:utf';
   
   import '../compiler.dart' as api;
  
positive.code:     if (uri.scheme != 'file') {
        fail('Error: Unhandled scheme ${uri.scheme} in $uri.');
      }
      IOSink output =
          new File(uriPathToNative(uri.path)).openWrite();
  
      CountingSink sink;
  
      onDone() {
        if (sourceMapFileName != null) {
          String sourceMapTag = '//@ sourceMappingURL=$sourceMapFileName\n';
          sink.count += sourceMapTag.length;
          output.write(sourceMapTag);
        }
        output.close();
        if (isPrimaryOutput) {
          charactersWritten += sink.count;
        }
      }
  
      var controller = new StreamController<String>(sync: true);
      controller.stream.listen(output.write, onDone: onDone);
      sink = new CountingSink(controller);
      return sink;
    }
  
    api.compile(uri, libraryRoot, packageRoot,
  
negative.code:                 getDepsOutput(inputProvider.sourceFiles));
      diagnosticHandler.info(
           'compiled ${inputProvider.dartCharactersRead} characters Dart '
           '-> $totalCharactersWritten characters $outputLanguage '
           'in ${relativize(currentDirectory, out, isWindows)}');
      if (!explicitOut) {
        String input = uriPathToNative(arguments[0]);
  