Add linked lists implementation.

As discussed on the mailing lists, the various linked list
implementations we currently use at a dozen of different places in the
calcurse source tree are inconvenient and should be replaced by a single
generic solution.

This is a first approach to introduce such a generic implemetation. It
provides following functions:

* llist_init(): Initialize a list.

* llist_free_inner(): Loop through a list and free all items.

* llist_free(): Free the list itself (but not the individual items).

* llist_first(): Get the first item of a list.

* llist_nth(): Get the nth item of a list.

* llist_next(): Get the successor of a list item.

* llist_find_first(): Find an item using a callback function.

* llist_find_next(): Find the next match using a callback function.

* llist_find_nth(): Find the nth item in a list (using a callback).

* llist_get_data(): Get a pointer to the actual data of a list item.

* llist_add(): Add an item at the end of a list.

* llist_add_sorted(): Add an item to a sorted list (using a comparison
                      callback function).

* llist_remove(): Remove an item from a list.

Linked lists are stored in "llist_t" structures, list items are to be
stored in "llist_item_t" structs.

All of the llist_*() functions either expect a pointer to a llist_t
structure (in case the function operates on the list itself) or a
pointer to a llist_item_t (llist_*_next() and llist_get_data()).

Signed-off-by: Lukas Fleischer <calcurse@cryptocrack.de>

1 files changed, 73 insertions, 0 deletions

diff --git a/src/llist.h b/src/llist.h
new file mode 100644
index 0000000..c13761d
--- /dev/null
+++ b/src/llist.h
@@ -0,0 +1,73 @@
+/*
+ * Calcurse - text-based organizer
+ *
+ * Copyright (c) 2004-2011 Frederic Culot <frederic@culot.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *      - Redistributions of source code must retain the above
+ *        copyright notice, this list of conditions and the
+ *        following disclaimer.
+ *
+ *      - Redistributions in binary form must reproduce the above
+ *        copyright notice, this list of conditions and the
+ *        following disclaimer in the documentation and/or other
+ *        materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Send your feedback or comments to : misc@calcurse.org
+ * Calcurse home page : http://calcurse.org
+ *
+ */
+
+/* Linked lists. */
+typedef struct llist_item llist_item_t;
+struct llist_item {
+  struct llist_item *next;
+  void              *data;
+};
+
+typedef struct llist llist_t;
+struct llist {
+  struct llist_item *head;
+};
+
+typedef int (*llist_fn_cmp_t) (void *, void *);
+typedef int (*llist_fn_match_t) (void *, long);
+typedef void (*llist_fn_free_t) (void *);
+
+/* Initialization and deallocation. */
+void          llist_init (llist_t *);
+void          llist_free (llist_t *);
+void          llist_free_inner (llist_t *, llist_fn_free_t);
+
+/* Retrieving list items. */
+llist_item_t *llist_first (llist_t *);
+llist_item_t *llist_nth (llist_t *, int);
+llist_item_t *llist_next (llist_item_t *);
+llist_item_t *llist_find_first (llist_t *, long, llist_fn_match_t);
+llist_item_t *llist_find_next (llist_item_t *, long, llist_fn_match_t);
+llist_item_t *llist_find_nth (llist_t *, int, long, llist_fn_match_t);
+
+/* Accessing list item data. */
+void         *llist_get_data (llist_item_t *);
+
+/* List manipulation. */
+void          llist_add (llist_t *, void *);
+void          llist_add_sorted (llist_t *, void *, llist_fn_cmp_t);
+void          llist_remove (llist_t *, llist_item_t *);
+