Tidy up reflection in advance of attempting to implement DynamicMessage.

There are corner cases where MessageDescriptor.{ClrType,Parser} will return null, and these are now documented. However, normally they *should* be implemented, even for descriptors of for dynamic messages. Ditto FieldDescriptor.Accessor.
We'll still need a fair amount of work to implement dynamic messages, but this change means that the public API will be remain intact.

Additionally, this change starts making use of C# 6 features in the files that it touches. This is far from exhaustive, and later PRs will have more.

Generated code changes coming in the next commit.

1 files changed, 4 insertions, 4 deletions

diff --git a/csharp/src/Google.Protobuf/Reflection/EnumDescriptor.cs b/csharp/src/Google.Protobuf/Reflection/EnumDescriptor.cs
index 285f26f3..57abbbff 100644
--- a/csharp/src/Google.Protobuf/Reflection/EnumDescriptor.cs
+++ b/csharp/src/Google.Protobuf/Reflection/EnumDescriptor.cs
@@ -43,13 +43,13 @@ namespace Google.Protobuf.Reflection
         private readonly EnumDescriptorProto proto;
         private readonly MessageDescriptor containingType;
         private readonly IList<EnumValueDescriptor> values;
-        private readonly Type generatedType;
+        private readonly Type clrType;
 
         internal EnumDescriptor(EnumDescriptorProto proto, FileDescriptor file, MessageDescriptor parent, int index, Type generatedType)
             : base(file, file.ComputeFullName(parent, proto.Name), index)
         {
             this.proto = proto;
-            this.generatedType = generatedType;
+            this.clrType = generatedType;
             containingType = parent;
 
             if (proto.Value.Count == 0)
@@ -73,9 +73,9 @@ namespace Google.Protobuf.Reflection
         public override string Name { get { return proto.Name; } }
 
         /// <summary>
-        /// The generated type for this enum, or <c>null</c> if the descriptor does not represent a generated type.
+        /// The CLR type for this enum. For generated code, this will be a CLR enum type.
         /// </summary>
-        public Type GeneratedType { get { return generatedType; } }
+        public Type ClrType { get { return clrType; } }
 
         /// <value>
         /// If this is a nested type, get the outer descriptor, otherwise null.