Implemented GeneratedExtension, although list handling may be incorrect.

7 files changed, 164 insertions, 103 deletions

diff --git a/csharp/ProtocolBuffers/ExtendableMessage.cs b/csharp/ProtocolBuffers/ExtendableMessage.cs
index cf43b03b..872b15b6 100644
--- a/csharp/ProtocolBuffers/ExtendableMessage.cs
+++ b/csharp/ProtocolBuffers/ExtendableMessage.cs
@@ -15,21 +15,21 @@ namespace Google.ProtocolBuffers {
     /// <summary>
     /// Checks if a singular extension is present.
     /// </summary>
-    public bool HasExtension(GeneratedExtension<TMessage, TBuilder> extension) {
+    public bool HasExtension(GeneratedExtensionBase<TMessage, TBuilder> extension) {
       return extensions.HasField(extension.Descriptor);
     }
 
     /// <summary>
     /// Returns the number of elements in a repeated extension.
     /// </summary>
-    public int GetExtensionCount<TExtension>(GeneratedExtension<TMessage, IList<TExtension>> extension) {
+    public int GetExtensionCount<TExtension>(GeneratedExtensionBase<TMessage, IList<TExtension>> extension) {
       return extensions.GetRepeatedFieldCount(extension.Descriptor);
     }
 
     /// <summary>
     /// Returns the value of an extension.
     /// </summary>
-    public TExtension GetExtension<TExtension>(GeneratedExtension<TMessage, TExtension> extension) {
+    public TExtension GetExtension<TExtension>(GeneratedExtensionBase<TMessage, TExtension> extension) {
       object value = extensions[extension.Descriptor];
       if (value == null) {
         return (TExtension) extension.MessageDefaultInstance;
@@ -41,7 +41,7 @@ namespace Google.ProtocolBuffers {
     /// <summary>
     /// Returns one element of a repeated extension.
     /// </summary>
-    public TExtension GetExtension<TExtension>(GeneratedExtension<TMessage, IList<TExtension>> extension, int index) {
+    public TExtension GetExtension<TExtension>(GeneratedExtensionBase<TMessage, IList<TExtension>> extension, int index) {
       return (TExtension) extension.SingularFromReflectionType(extensions[extension.Descriptor, index]);
     }
 
diff --git a/csharp/ProtocolBuffers/ExtensionRegistry.cs b/csharp/ProtocolBuffers/ExtensionRegistry.cs
index 9cda6a84..c8f31d37 100644
--- a/csharp/ProtocolBuffers/ExtensionRegistry.cs
+++ b/csharp/ProtocolBuffers/ExtensionRegistry.cs
@@ -88,7 +88,7 @@ namespace Google.ProtocolBuffers {
     /// <summary>
     /// Add an extension from a generated file to the registry.
     /// </summary>
-    public void Add<TContainer, TExtension> (GeneratedExtension<TContainer, TExtension> extension) 
+    public void Add<TContainer, TExtension> (GeneratedExtensionBase<TContainer, TExtension> extension) 
         where TContainer : IMessage<TContainer> {
       if (extension.Descriptor.MappedType == MappedType.Message) {
         Add(new ExtensionInfo(extension.Descriptor, extension.MessageDefaultInstance));
diff --git a/csharp/ProtocolBuffers/GeneratedExtension.cs b/csharp/ProtocolBuffers/GeneratedExtension.cs
deleted file mode 100644
index 667b4531..00000000
--- a/csharp/ProtocolBuffers/GeneratedExtension.cs
+++ /dev/null
@@ -1,97 +0,0 @@
-using Google.ProtocolBuffers.Descriptors;
-using System;
-using System.Collections.Generic;
-using System.Reflection;
-
-namespace Google.ProtocolBuffers {
-
-  public static class GeneratedExtension {
-
-    public static GeneratedExtension<TContainer, TExtension> CreateExtension<TContainer, TExtension>(FieldDescriptor descriptor)
-        where TContainer : IMessage<TContainer> {
-      if (descriptor.IsRepeated) {
-        throw new ArgumentException("Must call CreateRepeatedGeneratedExtension() for repeated types.");
-      }
-      return new GeneratedExtension<TContainer, TExtension>(descriptor);
-    }
-
-    public static GeneratedExtension<TContainer, IList<TExtension>> CreateRepeatedExtension<TContainer, TExtension>(FieldDescriptor descriptor) 
-        where TContainer : IMessage<TContainer> {
-      if (descriptor.IsRepeated) {
-        throw new ArgumentException("Must call CreateRepeatedGeneratedExtension() for repeated types.");
-      }
-      return new GeneratedExtension<TContainer, IList<TExtension>>(descriptor);
-    }
-  }
-
-  /// <summary>
-  /// Base class for all generated extensions.
-  /// </summary>
-  /// <remarks>
-  /// The protocol compiler generates a static singleton instance of this
-  /// class for each extension. For exmaple, imagine a .proto file with:
-  /// <code>
-  /// message Foo {
-  ///   extensions 1000 to max
-  /// }
-  /// 
-  /// extend Foo {
-  ///   optional int32 bar;
-  /// }
-  /// </code>
-  /// Then MyProto.Foo.Bar has type GeneratedExtension&lt;MyProto.Foo,int&gt;.
-  /// <para />
-  /// In general, users should ignore the details of this type, and
-  /// simply use the static singletons as parmaeters to the extension accessors
-  /// in ExtendableMessage and ExtendableBuilder.
-  /// </remarks>
-  public class GeneratedExtension<TContainer, TExtension> where TContainer : IMessage<TContainer> {
-    private readonly IMessage messageDefaultInstance;
-    private readonly FieldDescriptor descriptor;
-
-    internal GeneratedExtension(FieldDescriptor descriptor) {
-      if (!descriptor.IsExtension) {
-        throw new ArgumentException("GeneratedExtension given a regular (non-extension) field.");
-      }
-
-      this.descriptor = descriptor;
-
-      switch (descriptor.MappedType) {
-        case MappedType.Message:
-          PropertyInfo defaultInstanceProperty = typeof(TExtension)
-              .GetProperty("DefaultInstance", BindingFlags.Static | BindingFlags.Public);
-          if (defaultInstanceProperty == null) {
-            throw new ArgumentException("No public static DefaultInstance property for type " + typeof(TExtension).Name);
-          }
-          messageDefaultInstance = (IMessage) defaultInstanceProperty.GetValue(null, null);
-          break;
-        case MappedType.Enum:
-          // FIXME(jonskeet): May not need this
-          //enumValueOf = getMethodOrDie(type, "valueOf",
-            //                           EnumValueDescriptor.class);
-          //enumGetValueDescriptor = getMethodOrDie(type, "getValueDescriptor");
-          messageDefaultInstance = null;
-          break;
-        default:
-          messageDefaultInstance = null;
-          break;
-      }
-    }
-
-    public FieldDescriptor Descriptor {
-      get { return descriptor; }
-    }
-
-    public IMessage MessageDefaultInstance {
-      get { return messageDefaultInstance; }
-    }
-
-    internal object SingularFromReflectionType(object p) {
-      throw new System.NotImplementedException();
-    }
-
-    internal object FromReflectionType(object value) {
-      throw new System.NotImplementedException();
-    }
-  }
-}
diff --git a/csharp/ProtocolBuffers/GeneratedExtensionBase.cs b/csharp/ProtocolBuffers/GeneratedExtensionBase.cs
new file mode 100644
index 00000000..40118388
--- /dev/null
+++ b/csharp/ProtocolBuffers/GeneratedExtensionBase.cs
@@ -0,0 +1,88 @@
+using System;
+using System.Collections.Generic;
+using System.Reflection;
+using System.Text;
+using Google.ProtocolBuffers.Descriptors;
+
+namespace Google.ProtocolBuffers {
+  /// <summary>
+  /// Base type for all generated extensions.
+  /// </summary>
+  /// <remarks>
+  /// The protocol compiler generates a static singleton instance of this
+  /// class for each extension. For exmaple, imagine a .proto file with:
+  /// <code>
+  /// message Foo {
+  ///   extensions 1000 to max
+  /// }
+  /// 
+  /// extend Foo {
+  ///   optional int32 bar;
+  /// }
+  /// </code>
+  /// Then MyProto.Foo.Bar has type GeneratedExtensionBase&lt;MyProto.Foo,int&gt;.
+  /// <para />
+  /// In general, users should ignore the details of this type, and
+  /// simply use the static singletons as parameters to the extension accessors
+  /// in ExtendableMessage and ExtendableBuilder.
+  /// The interface implemented by both GeneratedException and GeneratedRepeatException,
+  /// to make it easier to cope with repeats separately.
+  /// </remarks>
+  public abstract class GeneratedExtensionBase<TContainer, TExtension> {
+
+    private readonly FieldDescriptor descriptor;
+    private readonly IMessage messageDefaultInstance;
+
+    protected GeneratedExtensionBase(FieldDescriptor descriptor) {
+      if (!descriptor.IsExtension) {
+        throw new ArgumentException("GeneratedExtension given a regular (non-extension) field.");
+      }
+
+      this.descriptor = descriptor;
+      if (descriptor.MappedType == MappedType.Message) {
+        PropertyInfo defaultInstanceProperty = typeof(TExtension)
+            .GetProperty("DefaultInstance", BindingFlags.Static | BindingFlags.Public);
+        if (defaultInstanceProperty == null) {
+          throw new ArgumentException("No public static DefaultInstance property for type " + typeof(TExtension).Name);
+        }
+        messageDefaultInstance = (IMessage)defaultInstanceProperty.GetValue(null, null);
+      }
+    }
+
+    public FieldDescriptor Descriptor {
+      get { return descriptor; }
+    }
+
+    /// <summary>
+    /// Returns the default message instance for extensions which are message types.
+    /// </summary>
+    public IMessage MessageDefaultInstance {
+      get { return messageDefaultInstance; }
+    }
+
+    public object SingularFromReflectionType(object value) {
+      switch (Descriptor.MappedType) {
+        case MappedType.Message:
+          if (value is TExtension) {
+            return value;
+          } else {
+            // It seems the copy of the embedded message stored inside the
+            // extended message is not of the exact type the user was
+            // expecting.  This can happen if a user defines a
+            // GeneratedExtension manually and gives it a different type.
+            // This should not happen in normal use.  But, to be nice, we'll
+            // copy the message to whatever type the caller was expecting.
+            return MessageDefaultInstance.CreateBuilderForType()
+                           .MergeFrom((IMessage)value).Build();
+          }
+        case MappedType.Enum:
+          // Just return a boxed int - that can be unboxed to the enum
+          return ((EnumValueDescriptor) value).Number;
+        default:
+          return value;
+      }
+    }
+
+    public abstract object FromReflectionType(object value);
+  }
+}
\ No newline at end of file
diff --git a/csharp/ProtocolBuffers/GeneratedRepeatException.cs b/csharp/ProtocolBuffers/GeneratedRepeatException.cs
new file mode 100644
index 00000000..d766d7f6
--- /dev/null
+++ b/csharp/ProtocolBuffers/GeneratedRepeatException.cs
@@ -0,0 +1,42 @@
+using System;
+using System.Collections.Generic;
+using Google.ProtocolBuffers.Descriptors;
+using System.Collections;
+
+namespace Google.ProtocolBuffers {
+  /// <summary>
+  /// Class used to represent repeat extensions in generated classes.
+  /// </summary>
+  public class GeneratedRepeatExtension<TContainer, TExtensionElement> : GeneratedExtensionBase<TContainer, IList<TExtensionElement>> {
+    private GeneratedRepeatExtension(FieldDescriptor field) : base(field) {
+    }
+
+    public static GeneratedExtensionBase<TContainer, IList<TExtensionElement>> CreateInstance(FieldDescriptor descriptor) {
+      if (descriptor.IsRepeated) {
+        throw new ArgumentException("Must call GeneratedRepeatExtension.CreateInstance() for repeated types.");
+      }
+      return new GeneratedRepeatExtension<TContainer, TExtensionElement>(descriptor);
+    }
+
+    /// <summary>
+    /// Converts the list to the right type.
+    /// TODO(jonskeet): Check where this is used, and whether we need to convert
+    /// for primitive types.
+    /// </summary>
+    /// <param name="value"></param>
+    /// <returns></returns>
+    public override object FromReflectionType(object value) {
+      if (Descriptor.MappedType == MappedType.Message ||
+          Descriptor.MappedType == MappedType.Enum) {
+        // Must convert the whole list.
+        List<TExtensionElement> result = new List<TExtensionElement>();
+        foreach (object element in (IEnumerable) value) {
+          ((IList) result).Add(SingularFromReflectionType(element));
+        }
+        return result;
+      } else {
+        return value;
+      }
+    }
+  }
+}
diff --git a/csharp/ProtocolBuffers/GeneratedSingleExtension.cs b/csharp/ProtocolBuffers/GeneratedSingleExtension.cs
new file mode 100644
index 00000000..11805293
--- /dev/null
+++ b/csharp/ProtocolBuffers/GeneratedSingleExtension.cs
@@ -0,0 +1,26 @@
+using System;
+using Google.ProtocolBuffers.Descriptors;
+
+namespace Google.ProtocolBuffers {
+
+  /// <summary>
+  /// Generated extension for a singular field.
+  /// </remarks>
+  public class GeneratedSingleExtension<TContainer, TExtension> : GeneratedExtensionBase<TContainer, TExtension>    
+      where TContainer : IMessage<TContainer> {
+
+    internal GeneratedSingleExtension(FieldDescriptor descriptor) : base(descriptor) {
+    }
+
+    public static GeneratedSingleExtension<TContainer, TExtension> CreateInstance(FieldDescriptor descriptor) {
+      if (descriptor.IsRepeated) {
+        throw new ArgumentException("Must call GeneratedRepeateExtension.CreateInstance() for repeated types.");
+      }
+      return new GeneratedSingleExtension<TContainer, TExtension>(descriptor);
+    }
+
+    public override object FromReflectionType(object value) {
+      return base.SingularFromReflectionType(value);
+    }
+  }
+}
diff --git a/csharp/ProtocolBuffers/ProtocolBuffers.csproj b/csharp/ProtocolBuffers/ProtocolBuffers.csproj
index 0cd9e88e..3735adb7 100644
--- a/csharp/ProtocolBuffers/ProtocolBuffers.csproj
+++ b/csharp/ProtocolBuffers/ProtocolBuffers.csproj
@@ -82,9 +82,11 @@
     <Compile Include="FieldAccess\RepeatedMessageAccessor.cs" />
     <Compile Include="FieldSet.cs" />
     <Compile Include="GeneratedBuilder.cs" />
-    <Compile Include="GeneratedExtension.cs" />
+    <Compile Include="GeneratedSingleExtension.cs" />
     <Compile Include="GeneratedMessage.cs" />
+    <Compile Include="GeneratedRepeatException.cs" />
     <Compile Include="IBuilder.cs" />
+    <Compile Include="GeneratedExtensionBase.cs" />
     <Compile Include="IMessage.cs" />
     <Compile Include="InvalidProtocolBufferException.cs" />
     <Compile Include="IRpcChannel.cs" />