new file mode 100644
--- /dev/null
+++ b/src/pt-colon.h
@@ -0,0 +1,93 @@
+/*
+
+Copyright (C) 1996, 1997 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 2, 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, write to the Free
+Software Foundation, 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+
+*/
+
+#if !defined (octave_tree_colon_h)
+#define octave_tree_colon 1
+
+#if defined (__GNUG__)
+#pragma interface
+#endif
+
+#include <string>
+
+class tree_walker;
+
+class octave_value;
+class octave_value_list;
+class octave_lvalue;
+
+#include "pt-exp.h"
+
+// Colon expressions.
+
+class
+tree_colon_expression : public tree_expression
+{
+public:
+
+  tree_colon_expression (int l = -1, int c = -1)
+    : tree_expression (l, c), op_base (0), op_limit (0), op_increment (0) { }
+
+  tree_colon_expression (tree_expression *e, int l = -1, int c = -1)
+    : tree_expression (l, c), op_base (e), op_limit (0), op_increment (0) { }
+
+  ~tree_colon_expression (void)
+    {
+      delete op_base;
+      delete op_limit;
+      delete op_increment;
+    }
+
+  tree_colon_expression *append (tree_expression *t);
+
+  bool rvalue_ok (void) const
+    { return true; }
+
+  octave_value rvalue (void);
+
+  octave_value_list rvalue (int nargout);
+
+  void eval_error (const string& s = string ());
+
+  tree_expression *base (void) { return op_base; }
+
+  tree_expression *limit (void) { return op_limit; }
+
+  tree_expression *increment (void) { return op_increment; }
+
+  void accept (tree_walker& tw);
+
+private:
+
+  // The components of the expression.
+  tree_expression *op_base;
+  tree_expression *op_limit;
+  tree_expression *op_increment;
+};
+
+#endif
+
+/*
+;;; Local Variables: ***
+;;; mode: C++ ***
+;;; End: ***
+*/