/*

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 (__GNUG__)
#pragma implementation
#endif

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include "error.h"
#include "oct-obj.h"
#include "ov.h"
#include "pt-cmd.h"
#include "pt-exp.h"
#include "pt-select.h"
#include "pt-stmt.h"
#include "pt-walk.h"

// If clauses.

tree_if_clause::~tree_if_clause (void)
{
  delete expr;
  delete list;
}

int
tree_if_clause::eval (void)
{
  if (is_else_clause () || expr->is_logically_true ("if"))
    {
      if (list)
	list->eval ();

      return 1;
    }

  return 0;
}

void
tree_if_clause::accept (tree_walker& tw)
{
  tw.visit_if_clause (*this);
}

// List of if commands.

void
tree_if_command_list::eval (void)
{
  for (Pix p = first (); p != 0; next (p))
    {
      tree_if_clause *t = this->operator () (p);

      if (t->eval () || error_state)
	break;
    }
}

void
tree_if_command_list::accept (tree_walker& tw)
{
  tw.visit_if_command_list (*this);
}

// If.

tree_if_command::~tree_if_command (void)
{
  delete list;
}

void
tree_if_command::eval (void)
{
  if (list)
    list->eval ();

  if (error_state > 0)
    ::error ("evaluating if command near line %d, column %d",
	     line (), column ());
}

void
tree_if_command::accept (tree_walker& tw)
{
  tw.visit_if_command (*this);
}

// Switch cases.

tree_switch_case::~tree_switch_case (void)
{
  delete label;
  delete list;
}

bool
tree_switch_case::label_matches (const octave_value& val)
{
  bool retval = false;

  octave_value label_value = label->rvalue ();

  if (! error_state)
    {
      if (label_value.is_defined ())
	{
	  octave_value tmp = do_binary_op (octave_value::eq,
					   val, label_value);

	  if (! error_state)
	    {
	      if (tmp.is_defined ())
		retval = tmp.is_true ();
	      else
		eval_error ();
	    }
	  else
	    eval_error ();
	}
      else
	eval_error ();
    }
  else
    eval_error ();

  return retval;
}

int
tree_switch_case::eval (const octave_value& val)
{
  int retval = 0;

  if (is_default_case () || label_matches (val))
    {
      if (list)
	list->eval ();

      retval = 1;
    }

  return retval;
}

void
tree_switch_case::eval_error (void)
{
  ::error ("evaluating switch case label");
}

void
tree_switch_case::accept (tree_walker& tw)
{
  tw.visit_switch_case (*this);
}

// List of switch cases.

void
tree_switch_case_list::eval (const octave_value& val)
{
  for (Pix p = first (); p != 0; next (p))
    {
      tree_switch_case *t = this->operator () (p);

      if (t->eval (val) || error_state)
	break;
    }
}

void
tree_switch_case_list::accept (tree_walker& tw)
{
  tw.visit_switch_case_list (*this);
}

// Switch.

tree_switch_command::~tree_switch_command (void)
{
  delete expr;
  delete list;
}

void
tree_switch_command::eval (void)
{
  if (expr)
    {
      octave_value val = expr->rvalue ();

      if (! error_state)
	{
	  if (list)
	    list->eval (val);

	  if (error_state)
	    eval_error ();
	}
      else
	eval_error ();
    }
  else
    ::error ("missing value in switch command near line %d, column %d",
	     line (), column ());
}

void
tree_switch_command::eval_error (void)
{
  ::error ("evaluating switch command near line %d, column %d",
	   line (), column ());
}

void
tree_switch_command::accept (tree_walker& tw)
{
  tw.visit_switch_command (*this);
}

/*
;;; Local Variables: ***
;;; mode: C++ ***
;;; End: ***
*/