diff options
Diffstat (limited to 'Documentation/technical/api-string-list.txt')
| -rw-r--r-- | Documentation/technical/api-string-list.txt | 98 |
1 files changed, 86 insertions, 12 deletions
diff --git a/Documentation/technical/api-string-list.txt b/Documentation/technical/api-string-list.txt index 293bb15d20..20be348834 100644 --- a/Documentation/technical/api-string-list.txt +++ b/Documentation/technical/api-string-list.txt @@ -1,8 +1,9 @@ string-list API =============== -The string_list API offers a data structure and functions to handle sorted -and unsorted string lists. +The string_list API offers a data structure and functions to handle +sorted and unsorted string lists. A "sorted" list is one whose +entries are sorted by string value in `strcmp()` order. The 'string_list' struct used to be called 'path_list', but was renamed because it is not specific to paths. @@ -20,8 +21,9 @@ If you need something advanced, you can manually malloc() the `items` member (you need this if you add things later) and you should set the `nr` and `alloc` members in that case, too. -. Adds new items to the list, using `string_list_append` or - `string_list_insert`. +. Adds new items to the list, using `string_list_append`, + `string_list_append_nodup`, `string_list_insert`, + `string_list_split`, and/or `string_list_split_in_place`. . Can check if a string is in the list using `string_list_has_string` or `unsorted_string_list_has_string` and get it from the list using @@ -29,17 +31,26 @@ member (you need this if you add things later) and you should set the . Can sort an unsorted list using `sort_string_list`. +. Can remove duplicate items from a sorted list using + `string_list_remove_duplicates`. + +. Can remove individual items of an unsorted list using + `unsorted_string_list_delete_item`. + +. Can remove items not matching a criterion from a sorted or unsorted + list using `filter_string_list`, or remove empty strings using + `string_list_remove_empty_items`. + . Finally it should free the list using `string_list_clear`. Example: ---- -struct string_list list; +struct string_list list = STRING_LIST_INIT_NODUP; int i; -memset(&list, 0, sizeof(struct string_list)); -string_list_append("foo", &list); -string_list_append("bar", &list); +string_list_append(&list, "foo"); +string_list_append(&list, "bar"); for (i = 0; i < list.nr; i++) printf("%s\n", list.items[i].string) ---- @@ -57,6 +68,20 @@ Functions * General ones (works with sorted and unsorted lists as well) +`filter_string_list`:: + + Apply a function to each item in a list, retaining only the + items for which the function returns true. If free_util is + true, call free() on the util members of any items that have + to be deleted. Preserve the order of the items that are + retained. + +`string_list_remove_empty_items`:: + + Remove any empty strings from the list. If free_util is true, + call free() on the util members of any items that have to be + deleted. Preserve the order of the items that are retained. + `print_string_list`:: Dump a string_list to stdout, useful mainly for debugging purposes. It @@ -80,7 +105,9 @@ Functions Insert a new element to the string_list. The returned pointer can be handy if you want to write something to the `util` pointer of the - string_list_item containing the just added string. + string_list_item containing the just added string. If the given + string already exists the insertion will be skipped and the + pointer to the existing item returned. + Since this function uses xrealloc() (which die()s if it fails) if the list needs to grow, it is safe not to check the pointer. I.e. you may @@ -91,23 +118,70 @@ write `string_list_insert(...)->util = ...;`. Look up a given string in the string_list, returning the containing string_list_item. If the string is not found, NULL is returned. +`string_list_remove_duplicates`:: + + Remove all but the first of consecutive entries that have the + same string value. If free_util is true, call free() on the + util members of any items that have to be deleted. + * Functions for unsorted lists only `string_list_append`:: - Append a new string to the end of the string_list. + Append a new string to the end of the string_list. If + `strdup_string` is set, then the string argument is copied; + otherwise the new `string_list_entry` refers to the input + string. + +`string_list_append_nodup`:: + + Append a new string to the end of the string_list. The new + `string_list_entry` always refers to the input string, even if + `strdup_string` is set. This function can be used to hand + ownership of a malloc()ed string to a `string_list` that has + `strdup_string` set. `sort_string_list`:: - Make an unsorted list sorted. + Sort the list's entries by string value in `strcmp()` order. `unsorted_string_list_has_string`:: It's like `string_list_has_string()` but for unsorted lists. + +`unsorted_string_list_lookup`:: + + It's like `string_list_lookup()` but for unsorted lists. + -This function needs to look through all items, as opposed to its +The above two functions need to look through all items, as opposed to their counterpart for sorted lists, which performs a binary search. +`unsorted_string_list_delete_item`:: + + Remove an item from a string_list. The `string` pointer of the items + will be freed in case the `strdup_strings` member of the string_list + is set. The third parameter controls if the `util` pointer of the + items should be freed or not. + +`string_list_split`:: +`string_list_split_in_place`:: + + Split a string into substrings on a delimiter character and + append the substrings to a `string_list`. If `maxsplit` is + non-negative, then split at most `maxsplit` times. Return the + number of substrings appended to the list. ++ +`string_list_split` requires a `string_list` that has `strdup_strings` +set to true; it leaves the input string untouched and makes copies of +the substrings in newly-allocated memory. +`string_list_split_in_place` requires a `string_list` that has +`strdup_strings` set to false; it splits the input string in place, +overwriting the delimiter characters with NULs and creating new +string_list_items that point into the original string (the original +string must therefore not be modified or freed while the `string_list` +is in use). + + Data structures --------------- |