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. Can remove individual items of an unsorted list using 33 `unsorted_string_list_delete_item`. 34 35. Finally it should free the list using `string_list_clear`. 36 37Example: 38 39---- 40struct string_list list; 41int i; 42 43memset(&list, 0, sizeof(struct string_list)); 44string_list_append(&list, "foo"); 45string_list_append(&list, "bar"); 46for (i = 0; i < list.nr; i++) 47 printf("%s\n", list.items[i].string) 48---- 49 50NOTE: It is more efficient to build an unsorted list and sort it 51afterwards, instead of building a sorted list (`O(n log n)` instead of 52`O(n^2)`). 53+ 54However, if you use the list to check if a certain string was added 55already, you should not do that (using unsorted_string_list_has_string()), 56because the complexity would be quadratic again (but with a worse factor). 57 58Functions 59--------- 60 61* General ones (works with sorted and unsorted lists as well) 62 63`print_string_list`:: 64 65 Dump a string_list to stdout, useful mainly for debugging purposes. It 66 can take an optional header argument and it writes out the 67 string-pointer pairs of the string_list, each one in its own line. 68 69`string_list_clear`:: 70 71 Free a string_list. The `string` pointer of the items will be freed in 72 case the `strdup_strings` member of the string_list is set. The second 73 parameter controls if the `util` pointer of the items should be freed 74 or not. 75 76* Functions for sorted lists only 77 78`string_list_has_string`:: 79 80 Determine if the string_list has a given string or not. 81 82`string_list_insert`:: 83 84 Insert a new element to the string_list. The returned pointer can be 85 handy if you want to write something to the `util` pointer of the 86 string_list_item containing the just added string. If the given 87 string already exists the insertion will be skipped and the 88 pointer to the existing item returned. 89+ 90Since this function uses xrealloc() (which die()s if it fails) if the 91list needs to grow, it is safe not to check the pointer. I.e. you may 92write `string_list_insert(...)->util = ...;`. 93 94`string_list_lookup`:: 95 96 Look up a given string in the string_list, returning the containing 97 string_list_item. If the string is not found, NULL is returned. 98 99* Functions for unsorted lists only 100 101`string_list_append`:: 102 103 Append a new string to the end of the string_list. 104 105`sort_string_list`:: 106 107 Make an unsorted list sorted. 108 109`unsorted_string_list_has_string`:: 110 111 It's like `string_list_has_string()` but for unsorted lists. 112 113`unsorted_string_list_lookup`:: 114 115 It's like `string_list_lookup()` but for unsorted lists. 116+ 117The above two functions need to look through all items, as opposed to their 118counterpart for sorted lists, which performs a binary search. 119 120`unsorted_string_list_delete_item`:: 121 122 Remove an item from a string_list. The `string` pointer of the items 123 will be freed in case the `strdup_strings` member of the string_list 124 is set. The third parameter controls if the `util` pointer of the 125 items should be freed or not. 126 127Data structures 128--------------- 129 130* `struct string_list_item` 131 132Represents an item of the list. The `string` member is a pointer to the 133string, and you may use the `util` member for any purpose, if you want. 134 135* `struct string_list` 136 137Represents the list itself. 138 139. The array of items are available via the `items` member. 140. The `nr` member contains the number of items stored in the list. 141. The `alloc` member is used to avoid reallocating at every insertion. 142 You should not tamper with it. 143. Setting the `strdup_strings` member to 1 will strdup() the strings 144 before adding them, see above.