--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/txt-eng.h	Fri Jun 26 21:12:09 2009 +0100
@@ -0,0 +1,188 @@
+/*
+
+Copyright (C) 2009 Michael Goffioul
+
+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 (txt_eng_h)
+#define txt_eng_h 1
+
+#include "base-list.h"
+
+class text_element;
+class text_element_string;
+class text_element_list;
+class text_subscript_element;
+class text_superscript_element;
+
+class text_processor;
+
+class
+OCTINTERP_API
+text_element
+{
+public:
+  text_element (void) { }
+
+  virtual ~text_element (void) { }
+
+  virtual void accept (text_processor& p) = 0;
+
+private:
+  text_element (const text_element&);
+};
+
+class
+OCTINTERP_API
+text_element_string : public text_element
+{
+public:
+  text_element_string (const std::string& s = "")
+      : text_element (), str (s) { }
+
+  ~text_element_string (void) { }
+
+  std::string string_value (void) const { return str; }
+
+  void accept (text_processor& p);
+
+private:
+  std::string str;
+
+private:
+  text_element_string (const text_element_string &);
+};
+
+class
+OCTINTERP_API
+text_element_list :
+    public text_element,
+    public octave_base_list<text_element *>
+{
+public:
+  text_element_list (void)
+      : text_element (), octave_base_list<text_element*> () { }
+
+  ~text_element_list (void)
+    {
+      while (! empty ())
+	{
+	  iterator it = begin ();
+	  delete (*it);
+	  erase (it);
+	}
+    }
+
+  void accept (text_processor& p);
+};
+
+class
+OCTINTERP_API
+text_subscript_element : public text_element_list
+{
+public:
+  text_subscript_element (void)
+      : text_element_list () { }
+
+  ~text_subscript_element (void) { }
+
+  void accept (text_processor& p);
+};
+
+class
+OCTINTERP_API
+text_superscript_element : public text_element_list
+{
+public:
+  text_superscript_element (void)
+      : text_element_list () { }
+
+  ~text_superscript_element (void) { }
+
+  void accept (text_processor& p);
+};
+
+class
+OCTINTERP_API
+text_processor
+{
+public:
+  virtual void visit (text_element_string& e) = 0;
+
+  virtual void visit (text_element_list& e)
+    {
+      for (text_element_list::iterator it = e.begin ();
+	   it != e.end (); ++it)
+	{
+	  (*it)->accept (*this);
+	}
+    }
+  
+  virtual void visit (text_subscript_element& e)
+    { visit (dynamic_cast<text_element_list&> (e)); }
+  
+  virtual void visit (text_superscript_element& e)
+    { visit (dynamic_cast<text_element_list&> (e)); }
+
+  virtual void reset (void) { }
+
+protected:
+  text_processor (void) { }
+
+  virtual ~text_processor (void) { } 
+};
+
+#define TEXT_ELEMENT_ACCEPT(cls) \
+inline void \
+cls::accept (text_processor& p) \
+{ p.visit (*this); }
+
+TEXT_ELEMENT_ACCEPT(text_element_string)
+TEXT_ELEMENT_ACCEPT(text_element_list)
+TEXT_ELEMENT_ACCEPT(text_subscript_element)
+TEXT_ELEMENT_ACCEPT(text_superscript_element)
+
+class
+OCTINTERP_API
+text_parser
+{
+public:
+  text_parser (void) { }
+
+  virtual ~text_parser (void) { }
+
+  virtual text_element* parse (const std::string& s) = 0;
+};
+
+class
+OCTINTERP_API
+text_parser_none : public text_parser
+{
+public:
+  text_parser_none (void) : text_parser () { }
+
+  ~text_parser_none (void) { }
+
+  text_element* parse (const std::string& s)
+    {
+      return new text_element_string (s);
+    }
+};
+
+#endif