Merge commit '36bca61764984ff5395653cf8377ec5daa71b709' as 'libs/protobuf'

libs/protobuf/csharp/src/Google.Protobuf/Reflection/IFieldAccessor.cs

@@ -0,0 +1,77 @@
+#region Copyright notice and license
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#endregion
+
+using System;
+using System.Collections;
+
+namespace Google.Protobuf.Reflection
+{
+    /// <summary>
+    /// Allows fields to be reflectively accessed.
+    /// </summary>
+    public interface IFieldAccessor
+    {
+        /// <summary>
+        /// Returns the descriptor associated with this field.
+        /// </summary>
+        FieldDescriptor Descriptor { get; }
+
+        /// <summary>
+        /// Clears the field in the specified message. (For repeated fields,
+        /// this clears the list.)
+        /// </summary>
+        void Clear(IMessage message);
+
+        /// <summary>
+        /// Fetches the field value. For repeated values, this will be an
+        /// <see cref="IList"/> implementation. For map values, this will be an
+        /// <see cref="IDictionary"/> implementation.
+        /// </summary>
+        object GetValue(IMessage message);
+
+        /// <summary>
+        /// Indicates whether the field in the specified message is set.
+        /// For proto3 fields that aren't explicitly optional, this throws an <see cref="InvalidOperationException"/>
+        /// </summary>
+        bool HasValue(IMessage message);
+
+        /// <summary>
+        /// Mutator for single "simple" fields only.
+        /// </summary>
+        /// <remarks>
+        /// Repeated fields are mutated by fetching the value and manipulating it as a list.
+        /// Map fields are mutated by fetching the value and manipulating it as a dictionary.
+        /// </remarks>
+        /// <exception cref="InvalidOperationException">The field is not a "simple" field.</exception>
+        void SetValue(IMessage message, object value);
+    }
+}