*** empty log message ***

diff --git a/MText.cs b/MText.cs
index 7b7a9d5..ecc24eb 100644 (file)
--- a/MText.cs
+++ b/MText.cs
@@ -94,7 +94,11 @@ namespace M17N.Core
 
     public static MText operator+ (MText mt1, MText mt2)
     {
-      return new MText (mt1.sb + mt2.sb);
+      MText mt = new MText (mt1.sb);
+
+      mt.sb.Append (mt2.sb);
+      mt.nchars = mt1.nchars + mt2.nchars;
+      return mt;
     }
 
     private static bool surrogate_high_p (char c)
@@ -161,6 +165,15 @@ namespace M17N.Core
       return i;
     }
 
+    private readonly bool readonlyp;
+
+    private void insert (int pos, MText mt2, int from, int to)
+    {
+      if (pos != cache_pos)
+       pos = pos_to_idx (pos);
+
+    }
+
     public int this[int i]
     {
       set {
@@ -187,6 +200,23 @@ namespace M17N.Core
                : sb[i]);
       }
     }
+
+    public MText dup ()
+    {
+      return (new MText (this.sb));
+    }
+
+    public MText ins (int pos, MText mt)
+    {
+      insert (pos, mt, 0, mt.nchars);
+      return this;
+    }
+
+    public MText ins (int pos, MText mt, int from, int to)
+    {
+      insert (pos, mt, from, to);
+      return this;
+    }
   }
 
   public class MTextProperty