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/*

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 *  matiec - a compiler for the programming languages defined in IEC 61131-3

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 *

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 *  Copyright (C) 2003-2011  Mario de Sousa (msousa@fe.up.pt)

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 *  Copyright (C) 2007-2011  Laurent Bessard and Edouard Tisserant

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 *

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 *  This program is free software: you can redistribute it and/or modify

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 *  it under the terms of the GNU General Public License as published by

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 *  the Free Software Foundation, either version 3 of the License, or

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 *  (at your option) any later version.

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 *

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 *  This program is distributed in the hope that it will be useful,

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 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

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 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

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 *  GNU General Public License for more details.

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 *

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 *  You should have received a copy of the GNU General Public License

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 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.

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 *

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 *

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 * This code is made available on the understanding that it will not be

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 * used in safety-critical situations without a full and competent review.

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 */

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/*

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 * An IEC 61131-3 compiler.

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 *

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 * Based on the

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 * FINAL DRAFT - IEC 61131-3, 2nd Ed. (2001-12-10)

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 *

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 */

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/*

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 * Case element iterator.

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 * Iterate through the elements of a case list.

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 *

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 * This is part of the 4th stage that generates

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 * a c++ source program equivalent to the IL and ST

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 * code.

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 */

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/* Given a case_list_c and a type of element, iterate through

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 * each element, returning the symbol of each element if from

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 * the good type...case_element_iterator_c

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 */

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#include "case_element_iterator.hh"

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#include "../main.hh" // required for ERROR() and ERROR_MSG() macros.

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//#define DEBUG

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#ifdef DEBUG

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#define TRACE(classname) printf("\n____%s____\n",classname);

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#else

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#define TRACE(classname)

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#endif

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void* case_element_iterator_c::handle_case_element(symbol_c *case_element) {

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  if (current_case_element == case_element) {

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    current_case_element = NULL;

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  }

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  else if (current_case_element == NULL) {

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	current_case_element = case_element;

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	return case_element;

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  }

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  /* Not found! */

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  return NULL;

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}

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void* case_element_iterator_c::iterate_list(list_c *list) {

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  void *res;

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  for (int i = 0; i < list->n; i++) {

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    res = list->elements[i]->accept(*this);

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    if (res != NULL)

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        return res;

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  }

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  return NULL;

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}

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/* start off at the first case element once again... */

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void case_element_iterator_c::reset(void) {

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  current_case_element = NULL;

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}

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/* initialize the iterator object.

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 * We must be given a reference to a case_list_c that will be analyzed...

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 */

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case_element_iterator_c::case_element_iterator_c(symbol_c *list, case_element_t element_type) {

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  /* do some consistency check... */

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  case_list_c* case_list = dynamic_cast<case_list_c*>(list);

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  if (NULL == case_list) ERROR;

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  /* OK. Now initialize this object... */

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  this->case_list = list;

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  this->wanted_element_type = element_type;

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  reset();

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}

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/* Skip to the next case element of type chosen. After object creation,

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 * the object references on case element _before_ the first, so

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 * this function must be called once to get the object to

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 * reference the first element...

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 *

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 * Returns the case element's symbol!

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 */

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symbol_c *case_element_iterator_c::next(void) {

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  void *res = case_list->accept(*this);

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  if (res == NULL) 

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    return NULL;

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  return current_case_element;

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}

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/******************************/

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/* B 1.2.1 - Numeric Literals */

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/******************************/

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void *case_element_iterator_c::visit(integer_c *symbol) {

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  switch (wanted_element_type) {

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	case element_single:

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	  return handle_case_element(symbol);

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	  break;

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	default:

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	  break;

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  }

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  return NULL;

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}

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void *case_element_iterator_c::visit(neg_integer_c *symbol) {

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  switch (wanted_element_type) {

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	case element_single:

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	  return handle_case_element(symbol);

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	  break;

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	default:

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	  break;

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  }

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  return NULL;

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}

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/********************************/

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/* B 1.3.3 - Derived data types */

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/********************************/

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/*  signed_integer DOTDOT signed_integer */

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void *case_element_iterator_c::visit(subrange_c *symbol) {

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  switch (wanted_element_type) {

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    case element_subrange:

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      return handle_case_element(symbol);

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      break;

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    default:

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      break;

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  }

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  return NULL;

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}

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/* enumerated_type_name '#' identifier */

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void *case_element_iterator_c::visit(enumerated_value_c *symbol) {

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  switch (wanted_element_type) {

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    case element_single:

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      return handle_case_element(symbol);

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      break;

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    default:

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      break;

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  }

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  return NULL;

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}

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/********************************/

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/* B 3.2.3 Selection Statements */

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/********************************/

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void *case_element_iterator_c::visit(case_list_c *symbol) {

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  return iterate_list(symbol);

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}

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