new file mode 100644
--- /dev/null
+++ b/src/pt-bp.cc
@@ -0,0 +1,711 @@
+/*
+
+Copyright (C) 2001 Ben Sapp
+
+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 (__GNUG__)
+#pragma implementation
+#endif
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include "ov-usr-fcn.h"
+#include "ov-list.h"
+#include "pager.h"
+#include "pt-all.h"
+
+void 
+tree_breakpoint::take_action (tree &tr)
+{
+  if (act == set)
+    {
+      tr.set_breakpoint ();
+      line = tr.line ();
+      found = true;
+    }
+  else if (act == clear)
+    {
+      tr.delete_breakpoint ();
+      found = true;
+    }
+  else if (act == list)
+    {
+      if (tr.is_breakpoint ())
+	{
+	  lst.append (octave_value (static_cast<double> (tr.line ())));
+	  line = tr.line () + 1;
+	}
+    }
+  else
+    panic_impossible ();
+
+  return;
+}
+
+void
+tree_breakpoint::visit_while_command (tree_while_command& cmd)
+{
+  if (found)
+    return;
+
+  if (cmd.line () >= line)
+    take_action (cmd);
+
+  tree_expression *expr = cmd.condition ();
+
+  if (expr)
+    expr->accept (*this);
+
+  tree_statement_list *list = cmd.body ();
+
+  if (list)
+    list->accept (*this);
+}
+
+void
+tree_breakpoint::visit_do_until_command (tree_do_until_command& cmd)
+{
+  tree_statement_list *lst = cmd.body ();
+
+  if (cmd.line () >= line)
+    take_action (cmd);
+
+  if (lst)
+    lst->accept (*this);
+
+  if (found)
+    return;
+
+  tree_expression *expr = cmd.condition ();
+
+  if (expr)
+    expr->accept (*this);
+}
+
+void 
+tree_breakpoint::visit_argument_list (tree_argument_list& lst)
+{
+  if (found)
+    return;
+
+  for (Pix p = lst.first (); p != 0; lst.next (p))
+    {
+      tree_expression *elt = lst(p);
+
+      if (elt)
+	elt->accept (*this);
+    }
+}
+
+void 
+tree_breakpoint::visit_binary_expression (tree_binary_expression& expr)
+{
+  if (found)
+    return;
+
+  tree_expression *lhs = expr.lhs ();
+  tree_expression *rhs = expr.rhs ();
+
+  if (lhs && lhs->line () >= line)
+    {
+      take_action (expr);
+      return;
+    }
+
+  if (rhs && rhs->line () >= line)
+    take_action (expr);  
+}
+
+void 
+tree_breakpoint::visit_break_command (tree_break_command& cmd)
+{
+  if (found)
+    return;
+
+  if (cmd.line () >= line)
+    take_action (cmd);
+}
+
+void
+tree_breakpoint::visit_colon_expression (tree_colon_expression& expr)
+{
+  if (found)
+    return;
+
+  tree_expression *base = expr.base (); 
+
+  if (base)
+    base->accept (*this);
+
+  tree_expression *increment = expr.increment (); 
+
+  if (increment)
+    increment->accept (*this);
+
+  tree_expression *limit = expr.limit (); 
+
+  if (limit)
+    limit->accept (*this);
+}
+
+void 
+tree_breakpoint::visit_continue_command (tree_continue_command& cmd)
+{
+  if (found)
+    return;
+
+  if (cmd.line () >= line)
+    take_action (cmd);
+}
+
+void 
+tree_breakpoint::visit_decl_command (tree_decl_command& cmd)
+{
+  if (found)
+    return;
+
+  tree_decl_init_list *init_list = cmd.initializer_list ();
+
+  if (init_list)
+    init_list->accept (*this);
+}
+
+void 
+tree_breakpoint::visit_decl_elt (tree_decl_elt& cmd)
+{
+  if (found)
+    return;
+
+  tree_identifier *ident = cmd.ident ();
+
+  if (ident)
+    ident->accept (*this);
+
+  tree_expression *expr = cmd.expression ();
+
+  if (expr) 
+    expr->accept (*this);
+
+}
+
+void 
+tree_breakpoint::visit_decl_init_list (tree_decl_init_list& lst)
+{
+  if (found)
+    return;
+
+  for (Pix p = lst.first (); p != 0; lst.next (p))
+    {
+      tree_decl_elt *elt = lst(p);
+
+      if (elt)
+	elt->accept (*this);
+    }
+}
+
+void 
+tree_breakpoint::visit_simple_for_command (tree_simple_for_command& cmd)
+{
+  if (found)
+    return;
+
+  if (cmd.line () >= line)
+    take_action (cmd);
+
+  tree_expression *expr = cmd.control_expr ();
+
+  if (expr)
+    expr->accept (*this);
+
+  tree_statement_list *list = cmd.body ();
+
+  if (list)
+    list->accept (*this);
+}
+
+void 
+tree_breakpoint::visit_complex_for_command (tree_complex_for_command& cmd)
+{
+  if (found)
+    return;
+
+  if (cmd.line () >= line)
+    take_action (cmd);
+
+  tree_expression *expr = cmd.control_expr ();
+
+  if (expr)
+    expr->accept (*this);
+
+  tree_statement_list *list = cmd.body ();
+
+  if (list)
+    list->accept (*this);
+
+}
+
+void 
+tree_breakpoint::visit_octave_user_function (octave_user_function& cmd)
+{
+  // we should not visit octave user functions because the function we are currently 
+  // in is the function where the breakpoint was requested
+}
+
+void 
+tree_breakpoint::visit_octave_user_function_header (octave_user_function& cmd)
+{
+  // Do nothing
+}
+
+void 
+tree_breakpoint::visit_octave_user_function_trailer (octave_user_function& cmd)
+{
+  // Do nothing
+}
+
+void 
+tree_breakpoint::visit_identifier (tree_identifier& id)
+{
+  if (found)
+    return;
+
+  if (id.line () >= line )
+    take_action (id);
+}
+
+void 
+tree_breakpoint::visit_if_clause (tree_if_clause& cmd)
+{
+  if (found)
+    return;
+
+  tree_expression *expr = cmd.condition ();
+
+  if (expr)
+    expr->accept (*this);
+
+  tree_statement_list *list = cmd.commands ();
+
+  if (list)
+    list->accept (*this);
+}
+
+void
+tree_breakpoint::visit_if_command (tree_if_command& cmd)
+{
+  if (found)
+    return;
+
+  tree_if_command_list *list = cmd.cmd_list ();
+
+  if (list)
+    list->accept (*this);
+}
+
+void
+tree_breakpoint::visit_if_command_list (tree_if_command_list& lst)
+{
+  if (found)
+    return;
+
+  for (Pix p = lst.first (); p != 0; lst.next (p))
+    {
+      tree_if_clause *elt = lst(p);
+
+      if (elt)
+	elt->accept (*this);
+    }
+}
+
+void 
+tree_breakpoint::visit_index_expression (tree_index_expression& cmd)
+{
+  if (found)
+    return;
+
+  tree_expression *expr = cmd.expression ();
+
+  if (expr)
+    if (expr->line () >= line)
+      take_action (*expr);
+
+  tree_argument_list *lst = cmd.arg_list ();
+
+  if (lst)
+    lst->accept (*this);
+}
+
+void 
+tree_breakpoint::visit_indirect_ref (tree_indirect_ref& cmd)
+{
+  if (found)
+    return;
+
+  if (cmd.line () >= line)
+    take_action (cmd);  
+}
+
+void 
+tree_breakpoint::visit_matrix (tree_matrix& mat)
+{
+  if (found)
+    return;
+
+  Pix p = mat.first ();
+
+  while (p)
+    {
+      tree_argument_list *elt = mat (p);
+      mat.next (p);
+
+      if (elt)
+	elt->accept (*this);
+    }
+}
+
+void 
+tree_breakpoint::visit_cell (tree_cell& cell)
+{
+  if (found)
+    return;
+
+  Pix p = cell.first ();
+
+  while (p)
+    {
+      tree_argument_list *elt = cell (p);
+      cell.next (p);
+
+      if (elt)
+	elt->accept (*this);
+    }
+}
+
+void 
+tree_breakpoint::visit_multi_assignment (tree_multi_assignment& expr)
+{
+  if (found)
+    return;
+
+  tree_argument_list *list = expr.left_hand_side ();
+
+  if (list)
+    list->accept (*this);
+
+  tree_expression *rhs = expr.right_hand_side ();
+
+  if (rhs)
+    rhs->accept (*this);
+}
+
+void 
+tree_breakpoint::visit_no_op_command (tree_no_op_command& cmd)
+{
+  if (found)
+    return;
+
+  if (cmd.line () >= line)
+    take_action (cmd);
+}
+
+void 
+tree_breakpoint::visit_constant (tree_constant& cmd)
+{
+  if (found)
+    return;
+
+  if (cmd.line () >= line)
+    take_action (cmd);
+}
+
+void 
+tree_breakpoint::visit_parameter_list (tree_parameter_list& lst)
+{
+  if (found)
+    return;
+
+  Pix p = lst.first ();
+
+  while (p)
+    {
+      tree_identifier *elt = lst(p);
+      lst.next (p);
+
+      if (elt)
+	elt->accept (*this);
+    }
+}
+
+void 
+tree_breakpoint::visit_plot_command (tree_plot_command& cmd)
+{
+  if (found)
+    return;
+
+  // Don't bother looking at the range plot list since they must be
+  // on the same line.
+
+  if (cmd.line () >= line)
+    take_action (cmd);
+}
+
+void
+tree_breakpoint::visit_plot_limits (plot_limits& cmd)
+{
+  // Do nothing.  This case will be handled in visit_tree_plot_command.
+}
+
+void 
+tree_breakpoint::visit_plot_range (plot_range& cmd)
+{
+  // Do nothing.  This case will be handled in visit_tree_plot_command.
+}
+
+void
+tree_breakpoint::visit_postfix_expression (tree_postfix_expression& expr)
+{
+  if (found)
+    return;
+
+  if (expr.line () >= line)
+    take_action (expr);
+
+  tree_expression *e = expr.operand ();
+
+  if (e)
+    e->accept (*this);
+}
+
+void 
+tree_breakpoint::visit_prefix_expression (tree_prefix_expression& expr)
+{
+  if (found)
+    return;
+
+  if (expr.line () >= line)
+    take_action (expr);
+
+  tree_expression *e = expr.operand ();
+
+  if (e)
+    e->accept (*this);    
+}
+
+void 
+tree_breakpoint::visit_return_command (tree_return_command& cmd)
+{
+  if (found)
+    return;
+
+  if (cmd.line () >= line)
+    take_action (cmd);
+}
+
+void
+tree_breakpoint::visit_return_list (tree_return_list& lst)
+{
+  if (found)
+    return;
+
+  Pix p = lst.first ();
+
+  while (p)
+    {
+      tree_index_expression *elt = lst(p);
+      lst.next (p);
+
+      if (elt)
+	elt->accept (*this);
+    }
+}
+
+void 
+tree_breakpoint::visit_simple_assignment (tree_simple_assignment& expr)
+{
+  if (found)
+    return;
+
+  if (expr.line () >= line)
+    take_action (expr);
+
+}
+
+void
+tree_breakpoint::visit_statement (tree_statement& stmt)
+{
+  if (found)
+    return;
+
+  tree_command *cmd = stmt.command ();
+
+  if (cmd)
+    cmd->accept (*this);
+  else
+    {
+      tree_expression *expr = stmt.expression ();
+
+      if (expr)
+	expr->accept (*this);
+    }
+}
+
+void
+tree_breakpoint::visit_statement_list (tree_statement_list& lst)
+{
+  if (found)
+    return;
+
+  for (Pix p = lst.first (); p != 0; lst.next (p))
+    {
+      tree_statement *elt = lst(p);
+
+      if (elt)
+	elt->accept (*this);
+    }
+}
+
+void 
+tree_breakpoint::visit_subplot (subplot& cmd)
+{
+  // Do nothing.  This case will be handled in visit_tree_plot_command.
+}
+
+void
+tree_breakpoint::visit_subplot_axes (subplot_axes& cmd)
+{
+  // Do nothing.  This caser will be handled in visit_tree_plot_command.
+}
+
+void
+tree_breakpoint::visit_subplot_list (subplot_list& cmd)
+{
+  // Do nothing.  This case will be handled in visit_tree_plot_command.
+}
+
+void 
+tree_breakpoint::visit_subplot_style (subplot_style& cmd)
+{
+  // Do nothing.  This case will be handled in visit_tree_plot_command.
+}
+
+void
+tree_breakpoint::visit_subplot_using (subplot_using& cmd)
+{
+  // Do nothing.  This case will be handled in visit_tree_plot_command.
+}
+
+void
+tree_breakpoint::visit_switch_case (tree_switch_case& cmd)
+{
+  if (found)
+    return;
+
+  // Disallow breakpoints on the label.
+
+  tree_statement_list *lst = cmd.commands ();
+
+  if (lst)
+    lst->accept (*this);
+}
+
+void 
+tree_breakpoint::visit_switch_case_list (tree_switch_case_list& lst)
+{
+  if (found)
+    return;
+
+  Pix p = lst.first ();
+
+  while (p)
+    {
+      tree_switch_case *elt = lst(p);
+
+      if (elt)
+	elt->accept (*this);
+
+      lst.next (p);
+    }
+}
+
+
+void 
+tree_breakpoint::visit_switch_command (tree_switch_command& cmd)
+{
+  if (found)
+    return;
+
+  tree_expression *expr = cmd.switch_value ();
+
+  if (expr)
+    expr->accept (*this);
+
+  tree_switch_case_list *lst = cmd.case_list ();
+
+  if (lst)
+    lst->accept (*this);
+}
+
+void
+tree_breakpoint::visit_try_catch_command (tree_try_catch_command& cmd)
+{
+  if (found)
+    return;
+
+  if (cmd.line () >= line)
+    take_action (cmd);
+
+  tree_statement_list *try_code = cmd.body ();
+
+  if (try_code)
+    try_code->accept (*this);
+
+  tree_statement_list *catch_code = cmd.cleanup ();
+
+  if (catch_code)
+    catch_code->accept (*this);
+}
+
+void
+tree_breakpoint::visit_unwind_protect_command (tree_unwind_protect_command& cmd)
+{
+  if (found)
+    return;
+
+  if (cmd.line () >= line)
+    take_action (cmd);
+
+  tree_statement_list *lst1 = cmd.body ();
+
+  if (lst1)
+    lst1->accept (*this);
+
+  tree_statement_list *lst2 = cmd.cleanup ();
+
+  if (lst2)
+    lst2->accept (*this);
+}
+
+/*
+;;; Local Variables: ***
+;;; mode: C++ ***
+;;; End: ***
+*/