Use HasToJson when set Reponse/Notification parameters.

pkg/analysis_server/lib/src/computer/computer_highlights.dart

 // Copyright (c) 2014, 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 computer.highlights;
 
+import 'package:analysis_server/src/collections.dart';
 import 'package:analysis_server/src/constants.dart';
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/element.dart';
 import 'package:analyzer/src/generated/scanner.dart';
 
 
 /**
  * A computer for [HighlightRegion]s in a Dart [CompilationUnit].
  */
 class DartUnitHighlightsComputer {
   final CompilationUnit _unit;
 
   final List<HighlightRegion> _regions = <HighlightRegion>[];
 
   DartUnitHighlightsComputer(this._unit);
 
   /**
    * Returns the computed highlight regions, not `null`.
    */
-  List<Map<String, Object>> compute() {
+  List<HighlightRegion> compute() {
     _unit.accept(new _DartUnitHighlightsComputerVisitor(this));
     _addCommentRanges();
-    return _regions.map((region) => region.toJson()).toList();
+    return _regions;
   }
 
   void _addCommentRanges() {
     Token token = _unit.beginToken;
     while (token != null && token.type != TokenType.EOF) {
       Token commentToken = token.precedingComments;
       while (commentToken != null) {
         HighlightType highlightType = null;
         if (commentToken.type == TokenType.MULTI_LINE_COMMENT) {
           if (commentToken.lexeme.startsWith('/**')) {
@@ skipping 277 matching lines @@
   }
 
   void _addRegion_tokenStart_tokenEnd(Token a, Token b, HighlightType type) {
     int offset = a.offset;
     int end = b.end;
     _addRegion(offset, end - offset, type);
   }
 }
 
 
-class HighlightRegion {
+class HighlightRegion implements HasToJson {
   final int offset;
   final int length;
   final HighlightType type;
 
   HighlightRegion(this.offset, this.length, this.type);
 
   factory HighlightRegion.fromJson(Map<String, Object> map) {
     HighlightType type = HighlightType.valueOf(map[TYPE]);
     return new HighlightRegion(map[OFFSET], map[LENGTH], type);
   }
@@ skipping 287 matching lines @@
     DartType type = node.type;
     if (type != null) {
       if (type.isDynamic && node.name.name == "dynamic") {
         computer._addRegion_node(node, HighlightType.TYPE_NAME_DYNAMIC);
         return null;
       }
     }
     return super.visitTypeName(node);
   }
 }