--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/parse-private.h	Sun Feb 05 15:41:42 2012 -0500
@@ -0,0 +1,96 @@
+/*
+
+Copyright (C) 2012 John W. Eaton
+
+This file is part of Octave.
+
+Octave is free software; you can redistribute it and/or modify it
+under the terms of the GNU General Public License as published by the
+Free Software Foundation; either version 3 of the License, or (at your
+option) any later version.
+
+Octave is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with Octave; see the file COPYING.  If not, see
+<http://www.gnu.org/licenses/>.
+
+*/
+
+#if !defined (octave_parse_private_h)
+#define octave_parse_private_h 1
+
+#include <stack>
+
+#include "symtab.h"
+
+// Keep track of symbol table information when parsing functions.
+class symtab_context
+{
+private:
+
+  class frame
+  {
+  public:
+    frame (symbol_table::scope_id s, symbol_table::scope_id c)
+      : m_scope (s), m_context (c) { }
+
+    frame (const frame& f) : m_scope (f.m_scope), m_context (f.m_context) { }
+
+    frame& operator = (const frame& f)
+    {
+      if (&f != this)
+        {
+          m_scope = f.m_scope;
+          m_context = f.m_context;
+        }
+
+      return *this;
+    }
+
+    ~frame (void) { }
+
+    symbol_table::scope_id scope (void) const { return m_scope; }
+    symbol_table::scope_id context (void) const { return m_context; }
+
+  private:
+
+    symbol_table::scope_id m_scope;
+    symbol_table::scope_id m_context;
+  };
+
+  std::stack<frame> frame_stack;
+
+public:
+  symtab_context (void) : frame_stack () { }
+
+  void clear (void)
+  {
+    while (! frame_stack.empty ())
+      frame_stack.pop ();
+  }
+
+  bool empty (void) const { return frame_stack.empty (); }
+
+  void pop (void)
+  {
+    frame tmp = frame_stack.top ();
+
+    symbol_table::set_scope_and_context (tmp.scope (), tmp.context ());
+
+    frame_stack.pop ();
+  }
+
+  void push (void)
+  {
+    frame_stack.push (frame (symbol_table::current_scope (),
+                             symbol_table::current_context ()));
+  }
+};
+
+extern symtab_context parser_symtab_context;
+
+#endif