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/*

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 * (c) 2003 Mario de Sousa

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 *

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

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

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 * License, or (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, but

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 * WITHOUT ANY WARRANTY; without even the implied warranty of

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

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 * Public License for more details.

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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 IL and ST 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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 * Stage 2

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 * =======

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 *

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 *  This file contains the syntax definition of the textual

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 *  languages IL and ST. The syntax parser, comprising the

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 *  2nd stage of the overall compiler, is generated by runing

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 *  bison on this file.

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 */

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

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

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

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

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

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/*******   The following syntax does not have any conflicts.    *******/

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

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/*******   P L E A S E    K E E P    I T    T H A T    W A Y !  *******/

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/*******   ===================================================  *******/

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

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

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

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

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

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%{

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#include <string.h>	/* required for strdup()  */

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/* declare the token parser generated by flex... */

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int yylex(void);

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/* declare the error handler defined at the end of this file */

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void yyerror (const char *error_msg);

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/* produce a more verbose parsing error message */

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#define YYERROR_VERBOSE

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/* Include debuging code.

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 * Printing of debug info must then be activated by setting

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 * the variable yydebug to 1.

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 */

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#define YYDEBUG 0

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/* file with declaration of absyntax classes... */

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

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/* file with declaration of token constants. Generated by bison! */

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#include "iec.y.hh"

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/* file with the declarations of symbol tables... */

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#include "../util/symtable.hh"

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/* an ugly hack!!

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 * We will probably not need it when we decide

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 *  to cut down the abstract syntax down to size.

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 *  We keep it as it is until we get to write

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 *  stages 3 and 4 of the compiler. Who knows,

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 *  we might just find out that we really do need

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 *  the abstract syntax tree to stay as it is

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 *  afterall!

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 */

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/* for each element <elem> in list_c * <list>

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 * execute the code <code>

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 */

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#define FOR_EACH_ELEMENT(elem, list, code) {		\

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  symbol_c *elem;					\

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

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    elem = list->elements[i];				\

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    code;						\

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  }							\

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}

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/* A macro for printing out internal parser errors... */

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#define ERROR error_exit(__FILE__,__LINE__)

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/* function defined in main.cc */

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extern void error_exit(const char *file_name, int line_no);

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

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/* The global symbol tables...   */

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

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/* NOTE: declared static because they are not accessed

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 *       directly by the lexical parser (flex), but rather

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 *       through the function get_identifier_token()

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 */

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/* A symbol table to store all the library elements */

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/* e.g.: <function_name , function_decl>

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 *       <fb_name , fb_decl>

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 *       <type_name , type_decl>

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 *       <program_name , program_decl>

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 *       <configuration_name , configuration_decl>

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 */

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static symtable_c<int, BOGUS_TOKEN_ID> library_element_symtable;

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/* A symbol table to store the declared variables of

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 * the function currently being parsed...

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 */

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static symtable_c<int, BOGUS_TOKEN_ID> variable_name_symtable;

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

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/* global variables...   */

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

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static symbol_c *tree_root = NULL;

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/* The name of the file currently being parsed...

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 * Note that flex accesses and updates this global variable

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 * apropriately whenever it comes across an (*#include <filename> *)

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 * directive...

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 */

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const char *current_filename = NULL;

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/* A global flag used to tell the parser if overloaded funtions should be allowed.

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 * The IEC 61131-3 standard allows overloaded funtions in the standard library,

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 * but disallows them in user code...

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 */

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bool allow_function_overloading = false;

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

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/* forward declarations */

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

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/* The functions declared here are defined at the end of this file... */

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/* Convert an il_operator_c into an identifier_c */

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symbol_c *il_operator_c_2_identifier_c(symbol_c *il_operator);

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/* print an error message */

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void print_err_msg(const char *filename, int lineno, const char *additional_error_msg);

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

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/* forward declarations */

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

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/* The functions declared here are defined in iec.flex... */

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void print_include_stack(void);

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%}

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%union {

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    symbol_c 	*leaf;

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    list_c	*list;

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    char 	*ID;	/* token value */

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    struct {

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      symbol_c	*first;

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      symbol_c	*second;

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    } double_symbol; /* used by il_simple_operator_clash_il_operand */

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}

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

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/* Prelimenary constructs... */

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

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%type <leaf> start

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%type <leaf>	any_identifier

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%token <ID>	prev_declared_variable_name_token

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%token <ID>	prev_declared_fb_name_token

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%type <leaf>	prev_declared_variable_name

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%type <leaf>	prev_declared_fb_name

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%token  <ID>	prev_declared_simple_type_name_token

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%token  <ID>	prev_declared_subrange_type_name_token

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%token  <ID>	prev_declared_enumerated_type_name_token

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%token  <ID>	prev_declared_array_type_name_token

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%token  <ID>	prev_declared_structure_type_name_token

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%token  <ID>	prev_declared_string_type_name_token

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%type  <leaf>	prev_declared_simple_type_name

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%type  <leaf>	prev_declared_subrange_type_name

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%type  <leaf>	prev_declared_enumerated_type_name

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%type  <leaf>	prev_declared_array_type_name

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%type  <leaf>	prev_declared_structure_type_name

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%type  <leaf>	prev_declared_string_type_name

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%token <ID>	prev_declared_derived_function_name_token

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%token <ID>	prev_declared_derived_function_block_name_token

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%token <ID>	prev_declared_program_type_name_token

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%type  <leaf>	prev_declared_derived_function_name

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%type  <leaf>	prev_declared_derived_function_block_name

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%type  <leaf>	prev_declared_program_type_name

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/* A bogus token that, in principle, flex MUST NEVER generate */

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/* USE 1:

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 * ======

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 * This token is currently also being used as the default

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 * initialisation value of the token_id member in

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 * the symbol_c base class.

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 *

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 * USE 2

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 * =====

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 * This token may also be used in the future to remove

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 * mysterious reduce/reduce conflicts due to the fact

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 * that our grammar may not be LALR(1) but merely LR(1).

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 * This means that bison cannot handle it without some

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 * caoxing from ourselves. We will then need this token

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 * to do the coaxing...

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 */

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%token BOGUS_TOKEN_ID

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/* The pragmas... */

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%token <ID>	pragma_token

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%type <leaf>	pragma

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/* Where do these tokens belong ?? */

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/* TODO: get the syntax parser to handle these tokens... */

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%token	EN

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%token	ENO

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

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/* B 0 - Programming Model */

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

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%type <list>	library

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%type <leaf>	library_element_declaration

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

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/* B 1.1 - Letters, digits and identifiers */

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

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/* Done totally within flex...

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  letter

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  digit

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  octal_digit

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  hex_digit

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*/

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%token <ID>	identifier_token

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%type  <leaf>	identifier

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

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/* B 1.2 - Constants */

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

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%type <leaf>	constant

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/* a helper symbol for expression */

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%type  <leaf> non_negative_constant

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

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/* B 1.2.1 - Numeric Literals */

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

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/* Done totally within flex...

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  bit

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*/

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%type  <leaf> numeric_literal

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/* helper symbol for non_negative_constant */

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%type  <leaf> non_negative_numeric_literal

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%type  <leaf> integer_literal

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%type  <leaf> signed_integer

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/* a helper symbol for non_negative_constant */

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%type  <leaf> non_negative_signed_integer

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%token <ID>   integer_token

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%type  <leaf> integer

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%token <ID>   binary_integer_token

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%type  <leaf> binary_integer

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%token <ID>   octal_integer_token

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%type  <leaf> octal_integer

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%token <ID>   hex_integer_token

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%type  <leaf> hex_integer

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%token <ID>   real_token

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%type  <leaf> real

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%type  <leaf> signed_real

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/* helper symbol for non_negative_real_literal */

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%type  <leaf> non_negative_signed_real

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%type  <leaf> real_literal

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/* helper symbol for non_negative_numeric_literal */

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%type  <leaf> non_negative_real_literal

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// %type  <leaf> exponent

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%type  <leaf> bit_string_literal

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%type  <leaf> boolean_literal

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%token FALSE

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%token TRUE

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

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/* B 1.2.2 - Character Strings */

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

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%token <ID>   single_byte_character_string_token

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%token <ID>   double_byte_character_string_token

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%type  <leaf> character_string

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%type  <leaf> single_byte_character_string

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%type  <leaf> double_byte_character_string

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

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/* B 1.2.3 - Time Literals */

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

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%type  <leaf> time_literal

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

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/* B 1.2.3.1 - Duration */

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

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%type  <leaf>	duration

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%type  <leaf>	interval

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%type  <leaf>	days

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%type  <leaf>	fixed_point

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%type  <leaf>	hours

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%type  <leaf>	minutes

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%type  <leaf>	seconds

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%type  <leaf>	milliseconds

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%type  <leaf>	integer_d

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%type  <leaf>	integer_h

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%type  <leaf>	integer_m

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%type  <leaf>	integer_s

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%type  <leaf>	integer_ms

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%type  <leaf>	fixed_point_d

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%type  <leaf>	fixed_point_h

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%type  <leaf>	fixed_point_m

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%type  <leaf>	fixed_point_s

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%type  <leaf>	fixed_point_ms

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%token <ID>	fixed_point_token

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%token <ID>	fixed_point_d_token

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%token <ID>	integer_d_token

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%token <ID>	fixed_point_h_token

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%token <ID>	integer_h_token

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%token <ID>	fixed_point_m_token

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%token <ID>	integer_m_token

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%token <ID>	fixed_point_s_token

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%token <ID>	integer_s_token

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%token <ID>	fixed_point_ms_token

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%token <ID>	integer_ms_token

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%token TIME

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%token T_SHARP

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

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/* B 1.2.3.2 - Time of day and Date */

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

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%type  <leaf>	time_of_day

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%type  <leaf>	daytime

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%type  <leaf>	day_hour

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%type  <leaf>	day_minute

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%type  <leaf>	day_second

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%type  <leaf>	date

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%type  <leaf>	date_literal

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%type  <leaf>	year

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%type  <leaf>	month

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%type  <leaf>	day

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%type  <leaf>	date_and_time

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%token TIME_OF_DAY

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%token DATE

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%token D_SHARP

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%token DATE_AND_TIME

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

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/* B 1.3 - Data Types */

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

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/* Strangely, the following symbol does seem to be required! */

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// %type  <leaf> data_type_name

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%type  <leaf> non_generic_type_name

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

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/* B 1.3.1 - Elementary Data Types */

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

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/* NOTES:

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 *

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 *    - To make the definition of bit_string_literal more

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 *      concise, it is useful to use an extra non-terminal

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 *      symbol (i.e. a grouping or construct) that groups the

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 *      following elements (BYTE, WORD, DWORD, LWORD).

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 *      Note that the definition of bit_string_type_name

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 *      (according to the spec) includes the above elements

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 *      and an extra BOOL.

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 *      We could use an extra construct with the first four

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 *      elements to be used solely in the definition of

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 *      bit_string_literal, but with the objective of not

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 *      having to replicate the actions (if we ever need

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 *      to change them, they would need to be changed in both

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 *      bit_string_type_name and the extra grouping), we

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 *      have re-defined bit_string_type_name as only including

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 *      the first four elements.

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 *      In order to have our parser implement the specification

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 *      correctly we have augmented every occurence of

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 *      bit_string_type_name in other rules with the BOOL

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 *      token. Since bit_string_type_name only appears in

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 *      the rule for elementary_type_name, this does not

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 *      seem to be a big concession to make!

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 *

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 *    - We have added a helper symbol to concentrate the

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 *      instantiation of STRING and WSTRING into a single

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 *      location (elementary_string_type_name).

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 *      These two elements show up in several other rules,

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 *      but we want to create the equivalent abstract syntax

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 *      in a single location of this file, in order to make

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 *      possible future changes easier to edit...

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 */

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%type  <leaf>	elementary_type_name

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%type  <leaf>	numeric_type_name

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%type  <leaf>	integer_type_name

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%type  <leaf>	signed_integer_type_name

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%type  <leaf>	unsigned_integer_type_name

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%type  <leaf>	real_type_name

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%type  <leaf>	date_type_name

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%type  <leaf>	bit_string_type_name

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/* helper symbol to concentrate the instantiation

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 * of STRING and WSTRING into a single location

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 */

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%type  <leaf>	elementary_string_type_name

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%token BYTE

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%token WORD

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%token DWORD

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%token LWORD

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%token LREAL

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%token REAL

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%token SINT

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%token INT

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%token DINT

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%token LINT

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%token USINT

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%token UINT

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%token UDINT

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%token ULINT

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%token WSTRING

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%token STRING

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%token BOOL

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%token TIME

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%token DATE

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%token DATE_AND_TIME

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%token DT

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%token TIME_OF_DAY

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%token TOD

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

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/* B 1.3.2 - Generic data types */

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

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/* Strangely, the following symbol does seem to be required! */

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// %type  <leaf>	generic_type_name

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/* The following tokens do not seem to be used either

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 * but we declare them so they become reserved words...

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 */

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%token ANY

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%token ANY_DERIVED

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%token ANY_ELEMENTARY

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%token ANY_MAGNITUDE

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%token ANY_NUM

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%token ANY_REAL

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%token ANY_INT

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%token ANY_BIT

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%token ANY_STRING

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%token ANY_DATE

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

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/* B 1.3.3 - Derived data types */

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

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%type  <leaf>	derived_type_name

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%type  <leaf>	single_element_type_name

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// %type  <leaf>	simple_type_name

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// %type  <leaf>	subrange_type_name

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// %type  <leaf>	enumerated_type_name

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// %type  <leaf>	array_type_name

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// %type  <leaf>	structure_type_name

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%type  <leaf>	data_type_declaration

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/* helper symbol for data_type_declaration */

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%type  <list>	type_declaration_list

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%type  <leaf>	type_declaration

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%type  <leaf>	single_element_type_declaration

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%type  <leaf>	simple_type_declaration

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%type  <leaf>	simple_spec_init

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%type  <leaf>	simple_specification

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%type  <leaf>	subrange_type_declaration

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%type  <leaf>	subrange_spec_init

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%type  <leaf>	subrange_specification

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%type  <leaf>	subrange