Annotation of 43BSDReno/usr.bin/make/lst.lib/lstForEachFrom.c, revision 1.1

1.1     ! root        1: /*
        !             2:  * Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
        !             3:  * All rights reserved.
        !             4:  *
        !             5:  * This code is derived from software contributed to Berkeley by
        !             6:  * Adam de Boor.
        !             7:  *
        !             8:  * Redistribution and use in source and binary forms are permitted
        !             9:  * provided that: (1) source distributions retain this entire copyright
        !            10:  * notice and comment, and (2) distributions including binaries display
        !            11:  * the following acknowledgement:  ``This product includes software
        !            12:  * developed by the University of California, Berkeley and its contributors''
        !            13:  * in the documentation or other materials provided with the distribution
        !            14:  * and in all advertising materials mentioning features or use of this
        !            15:  * software. Neither the name of the University nor the names of its
        !            16:  * contributors may be used to endorse or promote products derived
        !            17:  * from this software without specific prior written permission.
        !            18:  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
        !            19:  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
        !            20:  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
        !            21:  */
        !            22: 
        !            23: #ifndef lint
        !            24: static char sccsid[] = "@(#)lstForEachFrom.c   5.3 (Berkeley) 6/1/90";
        !            25: #endif /* not lint */
        !            26: 
        !            27: /*-
        !            28:  * lstForEachFrom.c --
        !            29:  *     Perform a given function on all elements of a list starting from
        !            30:  *     a given point.
        !            31:  */
        !            32: 
        !            33: #include       "lstInt.h"
        !            34: 
        !            35: /*-
        !            36:  *-----------------------------------------------------------------------
        !            37:  * Lst_ForEachFrom --
        !            38:  *     Apply the given function to each element of the given list. The
        !            39:  *     function should return 0 if traversal should continue and non-
        !            40:  *     zero if it should abort. 
        !            41:  *
        !            42:  * Results:
        !            43:  *     None.
        !            44:  *
        !            45:  * Side Effects:
        !            46:  *     Only those created by the passed-in function.
        !            47:  *
        !            48:  *-----------------------------------------------------------------------
        !            49:  */
        !            50: /*VARARGS2*/
        !            51: void
        !            52: Lst_ForEachFrom (l, ln, proc, d)
        !            53:     Lst                        l;
        !            54:     LstNode                    ln;
        !            55:     register int       (*proc)();
        !            56:     register ClientData        d;
        !            57: {
        !            58:     register ListNode  tln = (ListNode)ln;
        !            59:     register List      list = (List)l;
        !            60:     register ListNode  next;
        !            61:     Boolean            done;
        !            62:     int                result;
        !            63:     
        !            64:     if (!LstValid (list) || LstIsEmpty (list)) {
        !            65:        return;
        !            66:     }
        !            67:     
        !            68:     do {
        !            69:        /*
        !            70:         * Take care of having the current element deleted out from under
        !            71:         * us.
        !            72:         */
        !            73:        
        !            74:        next = tln->nextPtr;
        !            75:        
        !            76:        tln->useCount++;
        !            77:        result = (*proc) (tln->datum, d);
        !            78:        tln->useCount--;
        !            79: 
        !            80:        /*
        !            81:         * We're done with the traversal if
        !            82:         *  - nothing's been added after the current node and
        !            83:         *  - the next node to examine is the first in the queue or
        !            84:         *    doesn't exist.
        !            85:         */
        !            86:        done = (next == tln->nextPtr &&
        !            87:                (next == NilListNode || next == list->firstPtr));
        !            88:        
        !            89:        next = tln->nextPtr;
        !            90: 
        !            91:        if (tln->flags & LN_DELETED) {
        !            92:            free((char *)tln);
        !            93:        }
        !            94:        tln = next;
        !            95:     } while (!result && !LstIsEmpty(list) && !done);
        !            96:     
        !            97: }
        !            98: 

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