# Double linked lists.
class List[E]
super Sequence[E]
+
# Access
+
redef fun [](index) do return get_node(index).item
redef fun []=(index, item) do get_node(index).item = item
end
# Append `l` to `self` but clear `l`.
- ##
+ #
# O(1)
fun link(l: List[E])
do
redef fun iterator: ListIterator[E] do return new ListIterator[E](self)
+ redef fun reverse_iterator: ListIterator[E] do return new ListReverseIterator[E](self)
# Build an empty list.
init do end
init from(coll: Collection[E]) do append(coll)
# The first node of the list
- var _head: nullable ListNode[E]
+ private var head: nullable ListNode[E] = null
# The last node of the list
- var _tail: nullable ListNode[E]
+ private var tail: nullable ListNode[E] = null
# Get the `i`th node. get `null` otherwise.
private fun get_node(i: Int): nullable ListNode[E]
super IndexedIterator[E]
redef fun item do return _node.item
+ # Set item `e` at self `index`.
fun item=(e: E) do _node.item = e
redef fun is_ok do return not _node == null
end
# Build a new iterator for `list`.
- private init(list: List[E])
+ init
do
- _list = list
- _node = list._head
- _index = 0
+ _node = _list._head
end
# The current list
- var _list: List[E]
+ private var list: List[E]
# The current node of the list
- var _node: nullable ListNode[E]
+ private var node: nullable ListNode[E] = null
# The index of the current node
- redef readable var _index: Int
+ redef var index = 0
# Remove the current item
fun delete
end
end
+private class ListReverseIterator[E]
+ super ListIterator[E]
+
+ redef fun next
+ do
+ _node = _node.prev
+ _index -= 1
+ end
+
+ init
+ do
+ var list = _list
+ _node = list._tail
+ _index = list.length
+ end
+end
+
# Linked nodes that constitute a linked list.
private class ListNode[E]
super Container[E]
- init(i: E)
- do
- item = i
- end
# The next node.
- readable writable var _next: nullable ListNode[E]
+ var next: nullable ListNode[E] = null
# The previous node.
- readable writable var _prev: nullable ListNode[E]
+ var prev: nullable ListNode[E] = null
end