root/l_l_insert.c

DEFINITIONS

1. List_ListInsert

/* 
 * List_ListInsert.c --
 *
 *      Source code for the List_ListInsert library procedure.
 *
 * Copyright 1988 Regents of the University of California
 * Permission to use, copy, modify, and distribute this
 * software and its documentation for any purpose and without
 * fee is hereby granted, provided that the above copyright
 * notice appear in all copies.  The University of California
 * makes no representations about the suitability of this
 * software for any purpose.  It is provided "as is" without
 * express or implied warranty.
 */

#ifndef lint
static char rcsid[] = "$Header: /sprite/src/lib/c/list/RCS/List_ListInsert.c,v 1.1 89/06/12 16:59:31 shirriff Exp $ SPRITE (Berkeley)";
#endif /* not lint */

#include <stdio.h>
#include "list.h"
 
/*
 * ----------------------------------------------------------------------------
 *
 * List_ListInsert --
 *
 *      Insert the list pointed to by headerPtr into a List after 
 *      destPtr.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      The list containing destPtr is modified to contain itemPtr.
 *      headerPtr no longer references a valid list.
 *
 * ----------------------------------------------------------------------------
 */
void
List_ListInsert(headerPtr, destPtr)
    register    List_Links *headerPtr;  /* structure to insert */
    register    List_Links *destPtr;    /* structure after which to insert it */
{
    if (headerPtr == (List_Links *) NIL || destPtr == (List_Links *) NIL
            || !headerPtr || !destPtr) {
        panic("List_ListInsert: headerPtr (%x) or destPtr (%x) is NIL.\n",
                  (unsigned int) headerPtr, (unsigned int) destPtr);
        return;
    }

    if (headerPtr->nextPtr != headerPtr) {
        headerPtr->prevPtr->nextPtr = destPtr->nextPtr;
        headerPtr->nextPtr->prevPtr = destPtr;
        destPtr->nextPtr->prevPtr = headerPtr->prevPtr;
        destPtr->nextPtr = headerPtr->nextPtr;
    }

    headerPtr->nextPtr = (List_Links *) NIL;
    headerPtr->prevPtr = (List_Links *) NIL;
}