usr/src/usr.bin/make/lst.lib/lstIsEmpty.c

/*
 * Copyright (c) 1988, 1989, 1990, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Adam de Boor.
 *
 * %sccs.include.redist.c%
 */

#ifndef lint
static char sccsid[] = "@(#)lstIsEmpty.c        8.2 (Berkeley) %G%";
#endif /* not lint */

/*-
 * LstIsEmpty.c --
 *      A single function to decide if a list is empty
 */

#include        "lstInt.h"

/*-
 *-----------------------------------------------------------------------
 * Lst_IsEmpty --
 *      Return TRUE if the given list is empty.
 *
 * Results:
 *      TRUE if the list is empty, FALSE otherwise.
 *
 * Side Effects:
 *      None.
 *
 *      A list is considered empty if its firstPtr == NilListNode (or if
 *      the list itself is NILLIST).
 *-----------------------------------------------------------------------
 */
Boolean
Lst_IsEmpty (l)
    Lst l;
{
    return ( ! LstValid (l) || LstIsEmpty(l));
}