other components

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>

Microsoft.Z3/Log.cs

@@ -0,0 +1,79 @@
+/*++
+Copyright (c) 2012 Microsoft Corporation
+
+Module Name:
+
+    Log.cs
+
+Abstract:
+
+    Z3 Managed API: Log
+
+Author:
+
+    Christoph Wintersteiger (cwinter) 2012-03-15
+
+Notes:
+    
+--*/
+
+using System;
+using System.Diagnostics.Contracts;
+
+namespace Microsoft.Z3
+{
+  /// <summary>
+  /// Interaction logging for Z3.
+  /// </summary>
+  /// <remarks>
+  /// Note that this is a global, static log and if multiple Context 
+  /// objects are created, it logs the interaction with all of them.
+  /// </remarks>
+    [ContractVerification(true)]
+    public static class Log
+  {   
+    private static bool m_is_open = false;
+
+    /// <summary>
+    /// Open an interaction log file.
+    /// </summary>
+    /// <param name="filename">the name of the file to open</param>
+    /// <returns>True if opening the log file succeeds, false otherwise.</returns>
+    public static bool Open(string filename)
+    {
+      m_is_open = true;      
+      return Native.Z3_open_log(filename) == 1;
+    }
+
+    /// <summary>
+    /// Closes the interaction log.
+    /// </summary>
+    public static void Close()
+    {
+      m_is_open = false;
+      Native.Z3_close_log();
+    }
+
+    /// <summary>
+    /// Appends the user-provided string <paramref name="s"/> to the interaction log.
+    /// </summary>    
+    public static void Append(string s)
+    {
+        Contract.Requires(isOpen());
+
+      if (!m_is_open)
+        throw new Z3Exception("Log cannot be closed.");      
+      Native.Z3_append_log(s);
+    }
+
+    /// <summary>
+    /// Checks whether the interaction log is opened.
+    /// </summary>
+    /// <returns>True if the interaction log is open, false otherwise.</returns>
+        [Pure]
+        public static bool isOpen()
+    {
+      return m_is_open;
+    }
+  }
+}