56 lines
1.8 KiB
C
56 lines
1.8 KiB
C
/*-
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* LstIsAtEnd.c --
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* Tell if the current node is at the end of the list.
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* The sequential functions access the list in a slightly different way.
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* CurPtr points to their idea of the current node in the list and they
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* access the list based on it. Because the list is circular, Lst_Next
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* and Lst_Prev will go around the list forever. Lst_IsAtEnd must be
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* used to determine when to stop.
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*
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* Copyright (c) 1988 by University of California Regents
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*
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* Permission to use, copy, modify, and distribute this
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* software and its documentation for any purpose and without
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* fee is hereby granted, provided that the above copyright
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* notice appears in all copies. Neither the University of California nor
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* Adam de Boor makes any representations about the suitability of this
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* software for any purpose. It is provided "as is" without
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* express or implied warranty.
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*/
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#if !defined(lint) && defined(keep_rcsid)
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static char *rcsid =
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"Id: lstIsAtEnd.c,v 1.6 88/11/17 20:53:14 adam Exp $ SPRITE (Berkeley)";
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#endif lint
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#include "lstInt.h"
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/*-
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*-----------------------------------------------------------------------
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* Lst_IsAtEnd --
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* Return true if have reached the end of the given list.
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*
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* Results:
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* TRUE if at the end of the list (this includes the list not being
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* open or being invalid) or FALSE if not. We return TRUE if the list
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* is invalid or unopend so as to cause the caller to exit its loop
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* asap, the assumption being that the loop is of the form
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* while (!Lst_IsAtEnd (l)) {
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* ...
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* }
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*
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* Side Effects:
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* None.
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*
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*-----------------------------------------------------------------------
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*/
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Boolean
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Lst_IsAtEnd (l)
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Lst l;
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{
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register List list = (List) l;
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return (!LstValid (l) || !list->isOpen ||
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(list->atEnd == Head) || (list->atEnd == Tail));
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}
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