Implemented TextFormatter

csharp/ProtocolBuffers/ByteString.cs

@@ -15,13 +15,15 @@
 // limitations under the License.
 using System.Text;
 using System;
+using System.Collections.Generic;
+using System.Collections;
 
 namespace Google.ProtocolBuffers {
   /// <summary>
   /// Immutable array of bytes.
   /// TODO(jonskeet): Implement the common collection interfaces?
   /// </summary>
-  public sealed class ByteString {
+  public sealed class ByteString : IEnumerable<byte> {
 
     private static readonly ByteString empty = new ByteString(new byte[0]);
 
@@ -105,6 +107,14 @@ namespace Google.ProtocolBuffers {
       return ToString(Encoding.UTF8);
     }
 
+    public IEnumerator<byte> GetEnumerator() {
+      return ((IEnumerable<byte>) bytes).GetEnumerator();
+    }
+
+    IEnumerator IEnumerable.GetEnumerator() {
+      return GetEnumerator();
+    }
+
     /// <summary>
     /// Creates a CodedInputStream from this ByteString's data.
     /// </summary>

csharp/ProtocolBuffers/ProtocolBuffers.csproj

@@ -87,6 +87,7 @@
     <Compile Include="InvalidProtocolBufferException.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="TextFormat.cs" />
+    <Compile Include="TextGenerator.cs" />
     <Compile Include="UninitializedMessageException.cs" />
     <Compile Include="UnknownField.cs" />
     <Compile Include="UnknownFieldSet.cs" />

csharp/ProtocolBuffers/TextGenerator.cs

+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Text;
+
+namespace Google.ProtocolBuffers {
+
+  /// <summary>
+  /// Helper class to control indentation
+  /// </summary>
+  internal class TextGenerator {
+
+    /// <summary>
+    /// Writer to write formatted text to.
+    /// </summary>
+    private readonly TextWriter writer;
+
+    /// <summary>
+    /// Keeps track of whether the next piece of text should be indented
+    /// </summary>
+    bool atStartOfLine = true;
+
+    /// <summary>
+    /// Keeps track of the current level of indentation
+    /// </summary>
+    readonly StringBuilder indent = new StringBuilder();
+
+    /// <summary>
+    /// Creates a generator writing to the given writer.
+    /// </summary>
+    internal TextGenerator(TextWriter writer) {
+      this.writer = writer;
+    }
+
+    /// <summary>
+    /// Indents text by two spaces. After calling Indent(), two spaces
+    /// will be inserted at the beginning of each line of text. Indent() may
+    /// be called multiple times to produce deeper indents.
+    /// </summary>
+    internal void Indent() {
+      indent.Append("  ");
+    }
+
+    /// <summary>
+    /// Reduces the current indent level by two spaces.
+    /// </summary>
+    internal void Outdent() {
+      if (indent.Length == 0) {
+        throw new InvalidOperationException("Too many calls to Outdent()");
+      }
+      indent.Length -= 2;
+    }
+
+    /// <summary>
+    /// Prints the given text to the output stream, indenting at line boundaries.
+    /// </summary>
+    /// <param name="text"></param>
+    public void Print(string text) {
+      int pos = 0;
+
+      for (int i = 0; i < text.Length; i++) {
+        if (text[i] == '\n') {
+          // TODO(jonskeet): Use Environment.NewLine?
+          Write(text.Substring(pos, i - pos + 1));
+          pos = i + 1;
+          atStartOfLine = true;
+        }
+      }
+      Write(text.Substring(pos));
+    }
+
+    private void Write(string data) {
+      if (atStartOfLine) {
+        atStartOfLine = false;
+        writer.Write(indent);
+      }
+      writer.Write(data);
+    }
+  }
+}