1

/*

     2

 * (c) 2003 Mario de Sousa

     3

 *

     4

 * Offered to the public under the terms of the GNU General Public License

     5

 * as published by the Free Software Foundation; either version 2 of the

     6

 * License, or (at your option) any later version.

     7

 *

     8

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

     9

 * WITHOUT ANY WARRANTY; without even the implied warranty of

    10

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General

    11

 * Public License for more details.

    12

 *

    13

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

    14

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

    15

 */

    16

    17

/*

    18

 * An IEC 61131-3 IL and ST compiler.

    19

 *

    20

 * Based on the

    21

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

    22

 *

    23

 */

    24

    25

    26

    27

/* Decomposes a variable instance name into its constituents,

    28

 * example:

    29

 *    window.points[1].coordinate.x

    30

 *

    31

 *  will succesfully return

    32

 *        - window

    33

 *        - points

    34

 *        - coordinate

    35

 *        - x

    36

 * on succesive calls to decompose_var_instance_name_c::next_part()

    37

 */

    38

    39

    40

    41

#include "../absyntax/visitor.hh"

    42

    43

    44

    45

class decompose_var_instance_name_c: null_visitor_c {

    46

    47

  private:

    48

    symbol_c *variable_name;

    49

    symbol_c *next_variable_name;

    50

    symbol_c *current_recursive_variable_name;

    51

    symbol_c *previously_returned_variable_name;

    52

    53

  public:

    54

    decompose_var_instance_name_c(symbol_c *variable_instance_name);

    55

    56

    symbol_c *next_part(void);

    57

    58

  private:

    59

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

    60

  /* B 1.4 - Variables */

    61

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

    62

    void *visit(symbolic_variable_c *symbol);

    63

    64

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

    65

  /* B.1.4.1   Directly Represented Variables */

    66

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

    67

    void *visit(direct_variable_c *symbol);

    68

    69

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

    70

  /* B.1.4.2   Multi-element Variables */

    71

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

    72

  /*  subscripted_variable '[' subscript_list ']' */

    73

  // SYM_REF2(array_variable_c, subscripted_variable, subscript_list)

    74

    void *visit(array_variable_c *symbol);

    75

    76

  /*  record_variable '.' field_selector */

    77

  /*  WARNING: input and/or output variables of function blocks

    78

   *           may be accessed as fields of a tructured variable!

    79

   *           Code handling a structured_variable_c must take

    80

   *           this into account!

    81

   */

    82

  //SYM_REF2(structured_variable_c, record_variable, field_selector)

    83

    void *visit(structured_variable_c *symbol);

    84

    85

}; // decompose_var_instance_name_c

    86

    87

    88

    89