1.1 --- a/docs/src/modules.md Thu May 03 10:09:49 2018 +0200
1.2 +++ b/docs/src/modules.md Thu May 03 10:44:33 2018 +0200
1.3 @@ -51,6 +51,47 @@
1.4 All common binary tree operations are implemented. Furthermore, this module
1.5 provides search functions via lower and upper bounds.
1.6
1.7 +### Filtering items with a time window
1.8 +
1.9 +Suppose you have a list of items which contain a `time_t` value and your task
1.10 +is to find all items within a time window `[t_start, t_end]`.
1.11 +With AVL Trees this is easy:
1.12 +```C
1.13 +/* ---------------------
1.14 + * Somewhere in a header
1.15 + */
1.16 +typedef struct {
1.17 + time_t ts;
1.18 + // other important data
1.19 +} MyObject;
1.20 +
1.21 +/* -----------
1.22 + * Source code
1.23 + */
1.24 +
1.25 +UcxAVLTree* tree = ucx_avl_new(ucx_longintcmp);
1.26 +// ... populate tree with objects, use '& MyObject.ts' as key ...
1.27 +
1.28 +
1.29 +// Now find every item, with 30 <= ts <= 70
1.30 +time_t ts_start = 30;
1.31 +time_t ts_end = 70;
1.32 +
1.33 +printf("Values in range:\n");
1.34 +for (
1.35 + UcxAVLNode* node = ucx_avl_find_node(
1.36 + tree, (intptr_t) &ts_start,
1.37 + ucx_longintdist, UCX_AVL_FIND_LOWER_BOUNDED);
1.38 + node && (*(time_t*)node->key) <= ts_end;
1.39 + node = ucx_avl_succ(node)
1.40 + ) {
1.41 + printf(" ts: %ld\n", ((MyObject*)node->value)->ts);
1.42 +}
1.43 +
1.44 +ucx_avl_free_content(tree, free);
1.45 +ucx_avl_free(tree);
1.46 +```
1.47 +
1.48 ## Buffer
1.49
1.50 *Header file:* [buffer.h](api/buffer_8h.html)
