Iter Who? IterList!

It's a doubly linked list with a cursor based api.
also an iterator!

O(1) pretty much everything (at and around the cursor).
Originally made it for Shard, but thought it could be useful to someone else.

Example

use iterlist::IterList;

let mut list = IterList::new();

list.push_prev(-1);
list.push_next(1);
list.push_next(2);
list.push_next(3);

assert_eq!(format!("{:?}", list), "[-1, 1, 2, 3]");

list.move_to(2);
assert_eq!(list.get_cursor(), Some(&2));

list.move_by(-2);
assert_eq!(list.index(), 0);

let mut cursor = list.as_cursor();
assert_eq!(cursor.next(), Some(&-1));
assert_eq!(cursor.next(), Some(&1));

assert_eq!(list.get(1), Some(&1));

list.move_by(2);
let (elem, _) = list.consume_forward().unwrap();
assert_eq!(elem, 2);

assert_eq!(format!("{:?}", list), "[-1, 1, 3]");

let num = list.fold(0, |acc, elem| acc + elem);

assert_eq!(num, 3);

Why would I want to use IterList?

• You're iterating over a list, and are removing/inserting elements as you go.
• You want to have multiple independent cursors on the same list.
• You need an iterator that you can move around in and modify.

Why wouldn't I want to use IterList?

Pretty much any other case. (lol)
It has all the disadvantages of a doubly linked list, and is MUCH slower at many front/back operations. Instead of pointers to front and back, IterList keeps the cursor and it's index. Meaning O(1) operations work only around the cursor.

Todos

• split - split the list at the cursor.
• append - append another list to the end of this one.
• prepend - prepend another list to the start of this one.
• drain - remove a range of elements (around the cursor) from the list.
• splice - replace a range of elements (around the cursor) with another list.
• DoubleEndedIterator for Cursor.
• mod sync - Sync + Send versions of the list and cursor.
• mod pool - semi-pool allocated list for grouping elements into contiguous memory.

If ya wanna add any of these, feel free to!