anchor.diff:        function(block, value) {
           for (var i in value) {
             if (value.hasOwnProperty(i)) {
  -            block(v);
  +            block(value[i]);
             }
           }
         }
  
positive.code:     _bodies.add(minify(body));
    }
  
    void addTopLevel(String name, String body) {
      _topLevel.add("var ${name} = ${body}");
    }
  
    List<String> _topLevel = [];
  
    void writePrelude() {
      if (_topLevel.isNotEmpty) {
        buff.write(_topLevel.join(";"));
        buff.write(";");
      }
      buff.write('(function(${_names.join(",")}){var λ = {"args": args};');
    }
  
    final RegExp _WHITESPACE = new RegExp(r'''\s{2,}(?=([^"]*("|')[^"']*("|'))*[^"']*$)''');
  
negative.code:     return input;
    }
  
    String generatePostlude() {
      var map = {};
  
      var i = 0;
      for (var n in _names) {
        if (_includes.contains(n)) {
          map[n] = _bodies[i];
        }
        i++;
      }
  
      return "})(${_bodies.where((it) => map.values.contains(it)).join(",")});";
    }
  }
  