new file mode 100644
--- /dev/null
+++ b/src/pt-cmd.h
@@ -0,0 +1,232 @@
+// Tree classes.                                      -*- C++ -*-
+/*
+
+Copyright (C) 1992, 1993, 1994 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, 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#if !defined (octave_tree_cmd_h)
+#define octave_tree_cmd_h 1
+
+#if defined (__GNUG__)
+#pragma interface
+#endif
+
+class tree_expression;
+class tree_index_expression;
+class tree_constant;
+class symbol_record;
+
+class tree_command;
+class tree_command_list;
+class tree_global_command;
+class tree_while_command;
+class tree_for_command;
+class tree_if_command;
+class tree_break_command;
+class tree_continue_command;
+class tree_return_command;
+
+/*
+ * A base class for commands.
+ */
+class
+tree_command : public tree
+{
+};
+
+/*
+ * A command or two to be executed.
+ */
+class
+tree_command_list : public tree_command
+{
+ public:
+  tree_command_list (void);
+  tree_command_list (tree *t);
+
+  ~tree_command_list (void);
+
+  tree_command_list *chain (tree *t);
+  tree_command_list *reverse (void);
+
+  void set_print_flag (int print);
+
+  tree_constant eval (int print);
+
+ private:
+  tree *command;		// Command to execute.
+  int print_flag;		// Print result of eval for this command?
+  tree_command_list *next;	// Next command in list.
+};
+
+/*
+ * Global.
+ */
+class
+tree_global_command : public tree_command
+{
+ public:
+  tree_global_command (int l = -1, int c = -1);
+  tree_global_command (symbol_record *s, int l = -1, int c = -1);
+  tree_global_command (symbol_record *s, tree_expression *e,
+		       int l = -1, int c = -1); 
+
+  ~tree_global_command (void);
+
+  tree_global_command *chain (symbol_record *s, int l = -1, int c = -1);
+  tree_global_command *chain (symbol_record *s, tree_expression *e,
+			      int l = -1, int c = -1);
+  tree_global_command *reverse (void);
+
+  tree_constant eval (int print);
+
+  void eval_error (void);
+
+ private:
+  symbol_record *sr;		// Symbol record from local symbol table.
+  tree_expression *rhs;		// RHS of assignment.
+  tree_global_command *next;	// Next global command.
+};
+
+/*
+ * While.
+ */
+class
+tree_while_command : public tree_command
+{
+ public:
+  tree_while_command (int l = -1, int c = -1);
+  tree_while_command (tree_expression *e, int l = -1, int c = -1);
+  tree_while_command (tree_expression *e, tree *lst, int l = -1, int c = -1);
+
+  ~tree_while_command (void);
+
+  tree_constant eval (int print);
+
+  void eval_error (void);
+
+ private:
+  tree_expression *expr;	// Expression to test.
+  tree *list;			// List of commands to execute.
+};
+
+/*
+ * For.
+ */
+class
+tree_for_command : public tree_command
+{
+ public:
+  tree_for_command (int l = -1, int c = -1);
+  tree_for_command (tree_index_expression *id, tree_expression *e, tree *lst,
+		    int l = -1, int c = -1);
+
+  ~tree_for_command (void);
+
+  tree_constant eval (int print);
+
+  void eval_error (void);
+
+ private:
+  tree_constant do_for_loop_once (tree_constant *rhs, int& quit);
+
+  tree_index_expression *id;	// Identifier to modify.
+  tree_expression *expr;	// Expression to evaluate.
+  tree *list;			// List of commands to execute.
+};
+
+/*
+ * Simple if.
+ */
+class
+tree_if_command : public tree_command
+{
+ public:
+  tree_if_command (int l = -1, int c = -1);
+  tree_if_command (tree *lst, int l = -1, int c = -1);
+  tree_if_command (tree_expression *e, tree *lst, int l = -1, int c = -1);
+
+  ~tree_if_command (void);
+
+  tree_if_command *chain (tree *lst, int l = -1, int c = -1);
+  tree_if_command *chain (tree_expression *e, tree *lst, int l = -1,
+			  int c = -1);
+  tree_if_command *reverse (void);
+
+  tree_constant eval (int print);
+
+  void eval_error (void);
+
+ private:
+  tree_expression *expr;	// Expression to test.
+  tree *list;			// Commands to execute.
+  tree_if_command *next;	// Next if command.
+};
+
+/*
+ * Break.
+ */
+class
+tree_break_command : public tree_command
+{
+ public:
+  tree_break_command (int l = -1, int c = -1);
+
+  ~tree_break_command (void);
+
+  tree_constant eval (int print);
+};
+
+/*
+ * Continue.
+ */
+class
+tree_continue_command : public tree_command
+{
+ public:
+  tree_continue_command (int l = -1, int c = -1);
+
+  ~tree_continue_command (void);
+
+  tree_constant eval (int print);
+};
+
+/*
+ * Return.
+ */
+class
+tree_return_command : public tree_command
+{
+ public:
+  tree_return_command (int l = -1, int c = -1);
+
+  ~tree_return_command (void);
+
+  tree_constant eval (int print);
+};
+
+#endif
+
+/*
+;;; Local Variables: ***
+;;; mode: C++ ***
+;;; page-delimiter: "^/\\*" ***
+;;; End: ***
+*/