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-rw-r--r--Documentation/technical/api-string-list.txt109
1 files changed, 95 insertions, 14 deletions
diff --git a/Documentation/technical/api-string-list.txt b/Documentation/technical/api-string-list.txt
index 293bb15d20..c08402b12e 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.
@@ -20,26 +21,36 @@ 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
`string_list_lookup` for sorted lists.
-. Can sort an unsorted list using `sort_string_list`.
+. Can sort an unsorted list using `string_list_sort`.
+
+. 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 +68,25 @@ Functions
* General ones (works with sorted and unsorted lists as well)
+`string_list_init`::
+
+ Initialize the members of the string_list, set `strdup_strings`
+ member according to the value of the second parameter.
+
+`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 +110,9 @@ 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 +123,70 @@ 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.
-`sort_string_list`::
+`string_list_append_nodup`::
- Make an unsorted list sorted.
+ 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.
+
+`string_list_sort`::
+
+ 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
---------------
@@ -126,3 +205,5 @@ Represents the list itself.
You should not tamper with it.
. Setting the `strdup_strings` member to 1 will strdup() the strings
before adding them, see above.
+. The `compare_strings_fn` member is used to specify a custom compare
+ function, otherwise `strcmp()` is used as the default function.