projects / unix-history / blame
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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 the above copyright notice and this paragraph are | |
| 10 | * duplicated in all such forms and that any documentation, | |
| 11 | * advertising materials, and other materials related to such | |
| 12 | * distribution and use acknowledge that the software was developed | |
| 13 | * by the University of California, Berkeley. The name of the | |
| 14 | * University may not be used to endorse or promote products derived | |
| 15 | * from this software without specific prior written permission. | |
| 16 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR | |
| 17 | * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED | |
| 18 | * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. | |
| 19 | */ | |
| 20 | ||
| 21 | #ifndef lint | |
| 22 | static char sccsid[] = "@(#)lstForEachFrom.c 5.2 (Berkeley) %G%"; | |
| 23 | #endif /* not lint */ | |
| 24 | ||
| c65fedcf KB |
25 | /*- |
| 26 | * lstForEachFrom.c -- | |
| 27 | * Perform a given function on all elements of a list starting from | |
| 28 | * a given point. | |
| c65fedcf | 29 | */ |
| c65fedcf KB |
30 | |
| 31 | #include "lstInt.h" | |
| 32 | ||
| 33 | /*- | |
| 34 | *----------------------------------------------------------------------- | |
| 35 | * Lst_ForEachFrom -- | |
| 36 | * Apply the given function to each element of the given list. The | |
| 37 | * function should return 0 if traversal should continue and non- | |
| 38 | * zero if it should abort. | |
| 39 | * | |
| 40 | * Results: | |
| 41 | * None. | |
| 42 | * | |
| 43 | * Side Effects: | |
| 44 | * Only those created by the passed-in function. | |
| 45 | * | |
| 46 | *----------------------------------------------------------------------- | |
| 47 | */ | |
| 48 | /*VARARGS2*/ | |
| 49 | void | |
| 50 | Lst_ForEachFrom (l, ln, proc, d) | |
| 51 | Lst l; | |
| 52 | LstNode ln; | |
| 53 | register int (*proc)(); | |
| 54 | register ClientData d; | |
| 55 | { | |
| 56 | register ListNode tln = (ListNode)ln; | |
| 57 | register List list = (List)l; | |
| 58 | register ListNode next; | |
| 59 | Boolean done; | |
| 60 | int result; | |
| 61 | ||
| 62 | if (!LstValid (list) || LstIsEmpty (list)) { | |
| 63 | return; | |
| 64 | } | |
| 65 | ||
| 66 | do { | |
| 67 | /* | |
| 68 | * Take care of having the current element deleted out from under | |
| 69 | * us. | |
| 70 | */ | |
| 71 | ||
| 72 | next = tln->nextPtr; | |
| 73 | ||
| 74 | tln->useCount++; | |
| 75 | result = (*proc) (tln->datum, d); | |
| 76 | tln->useCount--; | |
| 77 | ||
| 78 | /* | |
| 79 | * We're done with the traversal if | |
| 80 | * - nothing's been added after the current node and | |
| 81 | * - the next node to examine is the first in the queue or | |
| 82 | * doesn't exist. | |
| 83 | */ | |
| 84 | done = (next == tln->nextPtr && | |
| 85 | (next == NilListNode || next == list->firstPtr)); | |
| 86 | ||
| 87 | next = tln->nextPtr; | |
| 88 | ||
| 89 | if (tln->flags & LN_DELETED) { | |
| 90 | free((char *)tln); | |
| 91 | } | |
| 92 | tln = next; | |
| 93 | } while (!result && !LstIsEmpty(list) && !done); | |
| 94 | ||
| 95 | } | |
| 96 |