19.2.7 Example - Manipulate an RDMLX Working List
The previous example can be changed to manipulate RDMLX lists.
The X_ALLOW_10_0_STRUCTURES define must be disabled by a set of #ifdef … #endif at the beginning of the C code, just before #include "x_bif000.h" :
#ifdef X_ALLOW_10_0_STRUCTURES
#undef X_ALLOW_10_0_STRUCTURES
#endif
Also the list entries's counter and list entry's index type must to be changed from X_SHORT to X_LIST_COUNT.
Used in an RDMLX function like this it could support the averaging of up to 999999 entries:
define field(#number) type(*dec) length(7)
def_list name(#list) fields(#number) type(*working)
entrys(999999)
define field(#mean) type(*dec) length(7)
use ud_average_list with_arg(#list) to_get(#mean)
An example of the user defined Built-In Function required to implement UD_AVERAGE_LIST might be coded like this:
/ ================================================================= */
/* ========== USER DEFINED BUILT-IN FUNCTION DEFINITION =========== */
/* ================================================================ */
/* */
/* Source File : U_BIF414.C */
/* Entry Point Name : U_BuiltIn_414 */
/* Linked DLL Name : U_BIF414.DLL */
/* Shared Object Name : u_bif414.O */
/* OS/Dependencies : Yes/No */
/* */
/* Amendment History : */
/* */
/* Task Id Date Description */
/* ======= ==== =========== */
/* */
/* ================================================================ */
#define U_BIF_FUNCTION U_BuiltIn_414
#define U_BIF_FUNCTION_NAME "U_BuiltIn_414"
#define U_BIF_DESCRIPTION "This is a description of this built-in"
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <limits.h>
#include "x_glodef.h"
#include "x_glousr.h"
#ifdef X_OPERATING_SYSTEM_WIN
#include <windows.h>
#endif
#include "x_funstr.h"
#include "x_funpro.h"
/* Enable RDMLX list*/
#ifdef X_ALLOW_10_0_STRUCTURES
#undef X_ALLOW_10_0_STRUCTURES
#endif
#include "x_bif000.h"
/*==================================================================*/
/* */
/* Arguments : pX_Ids - Standard X_IDS system definition */
/* pX_Pro - Standard X_PRO process definition */
/* pX_Fun - Standard X_FUN function definition */
/* pX_Bif - Standard X_BIF built-in definition */
/* X_Fld[: - Standard X_FLD field definitions */
/* X_List[: - Standard X_LIST list definitions */
/* sInCount - Number of arguments passed */
/* sInVec[: - Vectors of arguments */
/* sRetCount - Number of return values */
/* sRetVec[: - Vectors of return values */
/* */
/*==================================================================*/
X_VOID_FUNCTION U_BIF_FUNCTION ( U_BIF_STANDARD_PARAMETERS )
{
/* ------------------------------------------------------------- */
/* Handle a shutdown request (usually no activity is required) */
/* ------------------------------------------------------------- */
if (U_BIF_SHUTDOWN_REQUEST)
{
U_BIF_SET_GOOD_RETURN
}
/* ------------------------------------------------------------- */
/* Else perform the requested activity */
/* ------------------------------------------------------------- */
else
{
U_BIF_DECLARE_LIST_POINTER (pListArg1)
X_LIST_COUNT lEntrys = 0 ; /* Instead of X_SHORT sEntrys = 0; */
X_LONG lAverage = 0;
/* ------------------------------------- */
/* Set list pointer and get entry count */
/* ------------------------------------- */
U_BIF_SET_ARG_LIST_POINTER (pListArg1, 0)
U_BIF_GET_LIST_CURRENT_ENTRYS (pListArg1, lEntrys)
/* ------------------------------------- */
/* If there is any entries in the list */
/* ------------------------------------- */
if (lEntrys > 0)
{
X_LIST_COUNT lCurrentEntry; /* Instead of X_SHORT sCurrentEntry; */
X_CHAR chFound;
X_LONG lValue;
X_DOUBLE dTotal = 0;
/* -------------------------------------- */
/* Process all list entries and calculate */
/* the average value of all of them */
/* -------------------------------------- */
for (lCurrentEntry = 1; lCurrentEntry <= lEntrys; lCurrentEntry ++)
{
U_BIF_GET_ENTRY_FROM_LIST (pListArg1, lCurrentEntry, chFound)
U_BIF_GET_LIST_COLUMN_AS_LONG (pListArg1, 0, lValue)
dTotal = dTotal + lValue;
}
lAverage = dTotal / lEntrys;
}
/* ------------------------------------- */
/* Return the result in return value 1 */
/* ------------------------------------- */
U_BIF_SET_RET_FROM_LONG (0, lAverage);
U_BIF_SET_GOOD_RETURN
}
/* ------------------------------------------------------------- */
/* Return control to caller */
/* ------------------------------------------------------------- */
U_BIF_RETURN;
}