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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 "../absyntax/visitor.hh"

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class case_element_iterator_c : public null_visitor_c {

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  public:

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    /* A type to specify the type of element.

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     */

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    typedef enum {

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      element_single,

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      element_subrange

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    } case_element_t ;

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  private:

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    /* a pointer to the case_list_c currently being analyzed */

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    symbol_c *case_list;

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    /* used when called to iterate() for a parameter */

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    symbol_c *current_case_element;

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    /* used to indicate the type of case element on which iterate */

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    case_element_t wanted_element_type;

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  private:

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    void* handle_case_element(symbol_c *case_element);

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    void* iterate_list(list_c *list);

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  public:

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

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    void reset(void);

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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(symbol_c *list, case_element_t element_type);

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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 *next(void);

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    private:

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

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    /* B 1.2.1 - Numeric Literals */

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

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    void *visit(integer_c *symbol);

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    void *visit(neg_integer_c *symbol);

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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 *visit(subrange_c *symbol);

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    /* enumerated_type_name '#' identifier */

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    void *visit(enumerated_value_c *symbol);

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

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    /* B 3.2.3 Selection Statements */

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

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    void *visit(case_list_c *symbol);

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}; // function_param_iterator_c

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