1 files changed, 5 insertions, 6 deletions
diff --git a/csharp/src/Google.Protobuf/JsonParser.cs b/csharp/src/Google.Protobuf/JsonParser.cs
index 4cbbd89d..c34f84fb 100644
--- a/csharp/src/Google.Protobuf/JsonParser.cs
+++ b/csharp/src/Google.Protobuf/JsonParser.cs
@@ -37,7 +37,6 @@ using System.Collections;
 using System.Collections.Generic;
 using System.Globalization;
 using System.IO;
-using System.Linq;
 using System.Text;
 using System.Text.RegularExpressions;
 
@@ -167,11 +166,7 @@ namespace Google.Protobuf
                 throw new InvalidProtocolBufferException("Expected an object");
             }
             var descriptor = message.Descriptor;
-            // TODO: Make this more efficient, e.g. by building it once in the descriptor.
-            // Additionally, we need to consider whether to parse field names in their original proto form,
-            // and any overrides in the descriptor. But yes, all of this should be in the descriptor somehow...
-            // the descriptor can expose the dictionary.
-            var jsonFieldMap = descriptor.Fields.InDeclarationOrder().ToDictionary(field => JsonFormatter.ToCamelCase(field.Name));
+            var jsonFieldMap = descriptor.Fields.ByJsonName();
             while (true)
             {
                 token = tokenizer.Next();
@@ -340,6 +335,8 @@ namespace Google.Protobuf
         /// </summary>
         /// <typeparam name="T">The type of message to create.</typeparam>
         /// <param name="json">The JSON to parse.</param>
+        /// <exception cref="InvalidJsonException">The JSON does not comply with RFC 7159</exception>
+        /// <exception cref="InvalidProtocolBufferException">The JSON does not represent a Protocol Buffers message correctly</exception>
         public T Parse<T>(string json) where T : IMessage, new()
         {
             return Parse<T>(new StringReader(json));
@@ -350,6 +347,8 @@ namespace Google.Protobuf
         /// </summary>
         /// <typeparam name="T">The type of message to create.</typeparam>
         /// <param name="jsonReader">Reader providing the JSON to parse.</param>
+        /// <exception cref="InvalidJsonException">The JSON does not comply with RFC 7159</exception>
+        /// <exception cref="InvalidProtocolBufferException">The JSON does not represent a Protocol Buffers message correctly</exception>
         public T Parse<T>(TextReader jsonReader) where T : IMessage, new()
         {
             T message = new T();