/*
 * Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Adam de Boor.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#ifndef lint
static char sccsid[] = "@(#)lstFindFrom.c	5.2 (Berkeley) 03/11/90";
#endif /* not lint */

/*-
 * LstFindFrom.c --
 *	Find a node on a list from a given starting point. Used by Lst_Find.
 */

#include	"lstInt.h"

/*-
 *-----------------------------------------------------------------------
 * Lst_FindFrom --
 *	Search for a node starting and ending with the given one on the
 *	given list using the passed datum and comparison function to
 *	determine when it has been found.
 *
 * Results:
 *	The found node or NILLNODE
 *
 * Side Effects:
 *	None.
 *
 *-----------------------------------------------------------------------
 */
LstNode
Lst_FindFrom (l, ln, d, cProc)
    Lst		      	l;
    register LstNode    ln;
    register ClientData d;
    register int	(*cProc)();
{
    register ListNode	tln;
    Boolean		found = FALSE;
    
    if (!LstValid (l) || LstIsEmpty (l) || !LstNodeValid (ln, l)) {
	return (NILLNODE);
    }
    
    tln = (ListNode)ln;
    
    do {
	if ((*cProc) (tln->datum, d) == 0) {
	    found = TRUE;
	    break;
	} else {
	    tln = tln->nextPtr;
	}
    } while (tln != (ListNode)ln && tln != NilListNode);
    
    if (found) {
	return ((LstNode)tln);
    } else {
	return (NILLNODE);
    }
}