Attach source range information to parsed YAML nodes.

pkg/yaml/lib/src/visitor.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.
 
 library yaml.visitor;
 
+import 'equality.dart';
 import 'model.dart';
-import 'yaml_map.dart';
 
 /// The visitor pattern for YAML documents.
 class Visitor {
   /// Returns [alias].
   visitAlias(AliasNode alias) => alias;
 
   /// Returns [scalar].
   visitScalar(ScalarNode scalar) => scalar;
 
   /// Visits each node in [seq] and returns a list of the results.
   visitSequence(SequenceNode seq)
       => seq.content.map((e) => e.visit(this)).toList();
 
   /// Visits each key and value in [map] and returns a map of the results.
   visitMapping(MappingNode map) {
-    var out = new YamlMap();
+    var out = deepEqualsMap();
     for (var key in map.content.keys) {
       out[key.visit(this)] = map.content[key].visit(this);
     }
     return out;
   }
 }