82 lines
2.8 KiB
C
82 lines
2.8 KiB
C
/*
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* Copyright (c) 1988, 1989, 1990, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* Adam de Boor.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#ifndef lint
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static char sccsid[] = "@(#)lstDeQueue.c 8.1 (Berkeley) 6/6/93";
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#endif /* not lint */
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/*-
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* LstDeQueue.c --
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* Remove the node and return its datum from the head of the list
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*/
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#include "lstInt.h"
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/*-
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*-----------------------------------------------------------------------
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* Lst_DeQueue --
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* Remove and return the datum at the head of the given list.
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*
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* Results:
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* The datum in the node at the head or (ick) NIL if the list
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* is empty.
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*
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* Side Effects:
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* The head node is removed from the list.
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*
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*-----------------------------------------------------------------------
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*/
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ClientData
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Lst_DeQueue (l)
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Lst l;
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{
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ClientData rd;
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register ListNode tln;
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tln = (ListNode) Lst_First (l);
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if (tln == NilListNode) {
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return ((ClientData) NIL);
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}
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rd = tln->datum;
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if (Lst_Remove (l, (LstNode)tln) == FAILURE) {
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return ((ClientData) NIL);
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} else {
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return (rd);
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}
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}
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