4 The string_list API offers a data structure and functions to handle
5 sorted and unsorted string lists. A "sorted" list is one whose
6 entries are sorted by string value in `strcmp()` order.
8 The 'string_list' struct used to be called 'path_list', but was renamed
9 because it is not specific to paths.
13 . Allocates and clears a `struct string_list` variable.
15 . Initializes the members. You might want to set the flag `strdup_strings`
16 if the strings should be strdup()ed. For example, this is necessary
17 when you add something like git_path("..."), since that function returns
18 a static buffer that will change with the next call to git_path().
20 If you need something advanced, you can manually malloc() the `items`
21 member (you need this if you add things later) and you should set the
22 `nr` and `alloc` members in that case, too.
24 . Adds new items to the list, using `string_list_append`,
25 `string_list_append_nodup`, `string_list_insert`,
26 `string_list_split`, and/or `string_list_split_in_place`.
28 . Can check if a string is in the list using `string_list_has_string` or
29 `unsorted_string_list_has_string` and get it from the list using
30 `string_list_lookup` for sorted lists.
32 . Can sort an unsorted list using `sort_string_list`.
34 . Can remove duplicate items from a sorted list using
35 `string_list_remove_duplicates`.
37 . Can remove individual items of an unsorted list using
38 `unsorted_string_list_delete_item`.
40 . Can remove items not matching a criterion from a sorted or unsorted
41 list using `filter_string_list`.
43 . Finally it should free the list using `string_list_clear`.
48 struct string_list list = STRING_LIST_INIT_NODUP;
51 string_list_append(&list, "foo");
52 string_list_append(&list, "bar");
53 for (i = 0; i < list.nr; i++)
54 printf("%s\n", list.items[i].string)
57 NOTE: It is more efficient to build an unsorted list and sort it
58 afterwards, instead of building a sorted list (`O(n log n)` instead of
61 However, if you use the list to check if a certain string was added
62 already, you should not do that (using unsorted_string_list_has_string()),
63 because the complexity would be quadratic again (but with a worse factor).
68 * General ones (works with sorted and unsorted lists as well)
70 `filter_string_list`::
72 Apply a function to each item in a list, retaining only the
73 items for which the function returns true. If free_util is
74 true, call free() on the util members of any items that have
75 to be deleted. Preserve the order of the items that are
80 Dump a string_list to stdout, useful mainly for debugging purposes. It
81 can take an optional header argument and it writes out the
82 string-pointer pairs of the string_list, each one in its own line.
86 Free a string_list. The `string` pointer of the items will be freed in
87 case the `strdup_strings` member of the string_list is set. The second
88 parameter controls if the `util` pointer of the items should be freed
91 * Functions for sorted lists only
93 `string_list_has_string`::
95 Determine if the string_list has a given string or not.
97 `string_list_insert`::
99 Insert a new element to the string_list. The returned pointer can be
100 handy if you want to write something to the `util` pointer of the
101 string_list_item containing the just added string. If the given
102 string already exists the insertion will be skipped and the
103 pointer to the existing item returned.
105 Since this function uses xrealloc() (which die()s if it fails) if the
106 list needs to grow, it is safe not to check the pointer. I.e. you may
107 write `string_list_insert(...)->util = ...;`.
109 `string_list_lookup`::
111 Look up a given string in the string_list, returning the containing
112 string_list_item. If the string is not found, NULL is returned.
114 `string_list_remove_duplicates`::
116 Remove all but the first of consecutive entries that have the
117 same string value. If free_util is true, call free() on the
118 util members of any items that have to be deleted.
120 * Functions for unsorted lists only
122 `string_list_append`::
124 Append a new string to the end of the string_list. If
125 `strdup_string` is set, then the string argument is copied;
126 otherwise the new `string_list_entry` refers to the input
129 `string_list_append_nodup`::
131 Append a new string to the end of the string_list. The new
132 `string_list_entry` always refers to the input string, even if
133 `strdup_string` is set. This function can be used to hand
134 ownership of a malloc()ed string to a `string_list` that has
139 Sort the list's entries by string value in `strcmp()` order.
141 `unsorted_string_list_has_string`::
143 It's like `string_list_has_string()` but for unsorted lists.
145 `unsorted_string_list_lookup`::
147 It's like `string_list_lookup()` but for unsorted lists.
149 The above two functions need to look through all items, as opposed to their
150 counterpart for sorted lists, which performs a binary search.
152 `unsorted_string_list_delete_item`::
154 Remove an item from a string_list. The `string` pointer of the items
155 will be freed in case the `strdup_strings` member of the string_list
156 is set. The third parameter controls if the `util` pointer of the
157 items should be freed or not.
159 `string_list_split`::
160 `string_list_split_in_place`::
162 Split a string into substrings on a delimiter character and
163 append the substrings to a `string_list`. If `maxsplit` is
164 non-negative, then split at most `maxsplit` times. Return the
165 number of substrings appended to the list.
167 `string_list_split` requires a `string_list` that has `strdup_strings`
168 set to true; it leaves the input string untouched and makes copies of
169 the substrings in newly-allocated memory.
170 `string_list_split_in_place` requires a `string_list` that has
171 `strdup_strings` set to false; it splits the input string in place,
172 overwriting the delimiter characters with NULs and creating new
173 string_list_items that point into the original string (the original
174 string must therefore not be modified or freed while the `string_list`
181 * `struct string_list_item`
183 Represents an item of the list. The `string` member is a pointer to the
184 string, and you may use the `util` member for any purpose, if you want.
186 * `struct string_list`
188 Represents the list itself.
190 . The array of items are available via the `items` member.
191 . The `nr` member contains the number of items stored in the list.
192 . The `alloc` member is used to avoid reallocating at every insertion.
193 You should not tamper with it.
194 . Setting the `strdup_strings` member to 1 will strdup() the strings
195 before adding them, see above.