/*

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, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301, USA.

*/

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

#include "error.h"
#include "oct-obj.h"
#include "pager.h"
#include "ov.h"
#include "pt-bp.h"
#include "pt-colon.h"
#include "pt-walk.h"

// Colon expressions.

tree_colon_expression *
tree_colon_expression::append (tree_expression *t)
{
  tree_colon_expression *retval = 0;

  if (op_base)
    {
      if (op_limit)
	{
	  if (op_increment)
	    ::error ("invalid colon expression");
	  else
	    {
	      // Stupid syntax:
	      //
	      // base : limit
	      // base : increment : limit

	      op_increment = op_limit;
	      op_limit = t;
	    }
	}
      else
	op_limit = t;

      retval = this;
    }
  else
    ::error ("invalid colon expression");

  return retval;
}

octave_value_list
tree_colon_expression::rvalue (int nargout)
{
  octave_value_list retval;

  if (nargout > 1)
    error ("invalid number of output arguments for colon expression");
  else
    retval = rvalue ();

  return retval;
}

octave_value
tree_colon_expression::make_range (const Matrix& m_base,
				   const Matrix& m_limit,
				   const Matrix& m_increment,
				   bool result_is_str, bool dq_str) const
{
  octave_value retval;

  bool base_empty = m_base.is_empty ();
  bool limit_empty = m_limit.is_empty ();
  bool increment_empty = m_increment.is_empty ();

  if (base_empty || limit_empty || increment_empty)
    retval = Range ();
  else
    {
      retval = Range (m_base(0), m_limit(0), m_increment(0));

      if (result_is_str)
	retval = retval.convert_to_str (false, true, dq_str ? '"' : '\'');
    }

  return retval;
}

octave_value
tree_colon_expression::make_range (const octave_value& ov_base,
				   const octave_value& ov_limit,
				   const octave_value& ov_increment) const
{
  octave_value retval;

  bool result_is_str = (ov_base.is_string () && ov_limit.is_string ());
  bool dq_str = (ov_base.is_dq_string () || ov_limit.is_dq_string ());

  Matrix m_base = ov_base.matrix_value (true);

  if (error_state)
    eval_error ("invalid base value in colon expression");
  else
    {
      Matrix m_limit = ov_limit.matrix_value (true);

      if (error_state)
	eval_error ("invalid limit value in colon expression");
      else
	{
	  Matrix m_increment = ov_increment.matrix_value (true);

	  if (error_state)
	    eval_error ("invalid increment value in colon expression");
	  else
	    retval = make_range (m_base, m_limit, m_increment,
				 result_is_str, dq_str);
	}
    }

  return retval;
}

octave_value
tree_colon_expression::rvalue (void)
{
  octave_value retval;

  MAYBE_DO_BREAKPOINT;
  
  if (error_state || ! op_base || ! op_limit)
    return retval;

  octave_value ov_base = op_base->rvalue ();

  if (error_state || ov_base.is_undefined ())
    eval_error ("invalid base value in colon expression");
  else
    {
      octave_value ov_limit = op_limit->rvalue ();

      if (error_state || ov_limit.is_undefined ())
	eval_error ("invalid limit value in colon expression");
      else
	{
	  octave_value ov_increment = 1.0;

	  if (op_increment)
	    {
	      ov_increment = op_increment->rvalue ();

	      if (error_state || ov_increment.is_undefined ())
		eval_error ("invalid increment value in colon expression");
	    }

	  if (! error_state)
	    retval = make_range (ov_base, ov_limit, ov_increment);
	}
    }

  return retval;
}

void
tree_colon_expression::eval_error (const std::string& s) const
{
  if (! s.empty ())
    ::error ("%s", s.c_str ());

  ::error ("evaluating colon expression near line %d column %d",
	   line (), column ());
}

int
tree_colon_expression::line (void) const
{
  return (op_base ? op_base->line ()
	  : (op_increment ? op_increment->line ()
	     : (op_limit ? op_limit->line ()
		: -1)));
}

int
tree_colon_expression::column (void) const
{
  return (op_base ? op_base->column ()
	  : (op_increment ? op_increment->column ()
	     : (op_limit ? op_limit->column ()
		: -1)));
}

void
tree_colon_expression::accept (tree_walker& tw)
{
  tw.visit_colon_expression (*this);
}

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