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| Commit | Line | Data |
|---|---|---|
| c65fedcf KB |
1 | /*- |
| 2 | * lstForEachFrom.c -- | |
| 3 | * Perform a given function on all elements of a list starting from | |
| 4 | * a given point. | |
| 5 | * | |
| 6 | * Copyright (c) 1988 by University of California Regents | |
| 7 | * | |
| 8 | * Permission to use, copy, modify, and distribute this | |
| 9 | * software and its documentation for any purpose and without | |
| 10 | * fee is hereby granted, provided that the above copyright | |
| 11 | * notice appears in all copies. Neither the University of California nor | |
| 12 | * Adam de Boor makes any representations about the suitability of this | |
| 13 | * software for any purpose. It is provided "as is" without | |
| 14 | * express or implied warranty. | |
| 15 | */ | |
| 16 | #ifndef lint | |
| 17 | static char *rcsid = | |
| 18 | "$Id: lstForEachFrom.c,v 1.8 89/07/13 13:55:55 adam Exp $ SPRITE (Berkeley)"; | |
| 19 | #endif lint | |
| 20 | ||
| 21 | #include "lstInt.h" | |
| 22 | ||
| 23 | /*- | |
| 24 | *----------------------------------------------------------------------- | |
| 25 | * Lst_ForEachFrom -- | |
| 26 | * Apply the given function to each element of the given list. The | |
| 27 | * function should return 0 if traversal should continue and non- | |
| 28 | * zero if it should abort. | |
| 29 | * | |
| 30 | * Results: | |
| 31 | * None. | |
| 32 | * | |
| 33 | * Side Effects: | |
| 34 | * Only those created by the passed-in function. | |
| 35 | * | |
| 36 | *----------------------------------------------------------------------- | |
| 37 | */ | |
| 38 | /*VARARGS2*/ | |
| 39 | void | |
| 40 | Lst_ForEachFrom (l, ln, proc, d) | |
| 41 | Lst l; | |
| 42 | LstNode ln; | |
| 43 | register int (*proc)(); | |
| 44 | register ClientData d; | |
| 45 | { | |
| 46 | register ListNode tln = (ListNode)ln; | |
| 47 | register List list = (List)l; | |
| 48 | register ListNode next; | |
| 49 | Boolean done; | |
| 50 | int result; | |
| 51 | ||
| 52 | if (!LstValid (list) || LstIsEmpty (list)) { | |
| 53 | return; | |
| 54 | } | |
| 55 | ||
| 56 | do { | |
| 57 | /* | |
| 58 | * Take care of having the current element deleted out from under | |
| 59 | * us. | |
| 60 | */ | |
| 61 | ||
| 62 | next = tln->nextPtr; | |
| 63 | ||
| 64 | tln->useCount++; | |
| 65 | result = (*proc) (tln->datum, d); | |
| 66 | tln->useCount--; | |
| 67 | ||
| 68 | /* | |
| 69 | * We're done with the traversal if | |
| 70 | * - nothing's been added after the current node and | |
| 71 | * - the next node to examine is the first in the queue or | |
| 72 | * doesn't exist. | |
| 73 | */ | |
| 74 | done = (next == tln->nextPtr && | |
| 75 | (next == NilListNode || next == list->firstPtr)); | |
| 76 | ||
| 77 | next = tln->nextPtr; | |
| 78 | ||
| 79 | if (tln->flags & LN_DELETED) { | |
| 80 | free((char *)tln); | |
| 81 | } | |
| 82 | tln = next; | |
| 83 | } while (!result && !LstIsEmpty(list) && !done); | |
| 84 | ||
| 85 | } | |
| 86 |