1string-list API 2=============== 3 4The string_list API offers a data structure and functions to handle sorted 5and unsorted string lists. 6 7The 'string_list' struct used to be called 'path_list', but was renamed 8because it is not specific to paths. 9 10The caller: 11 12. Allocates and clears a `struct string_list` variable. 13 14. Initializes the members. You might want to set the flag `strdup_strings` 15 if the strings should be strdup()ed. For example, this is necessary 16 when you add something like git_path("..."), since that function returns 17 a static buffer that will change with the next call to git_path(). 18+ 19If you need something advanced, you can manually malloc() the `items` 20member (you need this if you add things later) and you should set the 21`nr` and `alloc` members in that case, too. 22 23. Adds new items to the list, using `string_list_append` or 24 `string_list_insert`. 25 26. Can check if a string is in the list using `string_list_has_string` or 27 `unsorted_string_list_has_string` and get it from the list using 28 `string_list_lookup` for sorted lists. 29 30. Can sort an unsorted list using `sort_string_list`. 31 32. Finally it should free the list using `string_list_clear`. 33 34Example: 35 36---- 37struct string_list list; 38int i; 39 40memset(&list, 0, sizeof(struct string_list)); 41string_list_append("foo", &list); 42string_list_append("bar", &list); 43for (i = 0; i < list.nr; i++) 44 printf("%s\n", list.items[i].string) 45---- 46 47NOTE: It is more efficient to build an unsorted list and sort it 48afterwards, instead of building a sorted list (`O(n log n)` instead of 49`O(n^2)`). 50+ 51However, if you use the list to check if a certain string was added 52already, you should not do that (using unsorted_string_list_has_string()), 53because the complexity would be quadratic again (but with a worse factor). 54 55Functions 56--------- 57 58* General ones (works with sorted and unsorted lists as well) 59 60`print_string_list`:: 61 62 Dump a string_list to stdout, useful mainly for debugging purposes. It 63 can take an optional header argument and it writes out the 64 string-pointer pairs of the string_list, each one in its own line. 65 66`string_list_clear`:: 67 68 Free a string_list. The `string` pointer of the items will be freed in 69 case the `strdup_strings` member of the string_list is set. The second 70 parameter controls if the `util` pointer of the items should be freed 71 or not. 72 73* Functions for sorted lists only 74 75`string_list_has_string`:: 76 77 Determine if the string_list has a given string or not. 78 79`string_list_insert`:: 80 81 Insert a new element to the string_list. The returned pointer can be 82 handy if you want to write something to the `util` pointer of the 83 string_list_item containing the just added string. 84+ 85Since this function uses xrealloc() (which die()s if it fails) if the 86list needs to grow, it is safe not to check the pointer. I.e. you may 87write `string_list_insert(...)->util = ...;`. 88 89`string_list_lookup`:: 90 91 Look up a given string in the string_list, returning the containing 92 string_list_item. If the string is not found, NULL is returned. 93 94* Functions for unsorted lists only 95 96`string_list_append`:: 97 98 Append a new string to the end of the string_list. 99 100`sort_string_list`:: 101 102 Make an unsorted list sorted. 103 104`unsorted_string_list_has_string`:: 105 106 It's like `string_list_has_string()` but for unsorted lists. 107 108`unsorted_string_list_lookup`:: 109 110 It's like `string_list_lookup()` but for unsorted lists. 111+ 112The above two functions need to look through all items, as opposed to their 113counterpart for sorted lists, which performs a binary search. 114 115Data structures 116--------------- 117 118* `struct string_list_item` 119 120Represents an item of the list. The `string` member is a pointer to the 121string, and you may use the `util` member for any purpose, if you want. 122 123* `struct string_list` 124 125Represents the list itself. 126 127. The array of items are available via the `items` member. 128. The `nr` member contains the number of items stored in the list. 129. The `alloc` member is used to avoid reallocating at every insertion. 130 You should not tamper with it. 131. Setting the `strdup_strings` member to 1 will strdup() the strings 132 before adding them, see above.