X-Git-Url: http://nitlanguage.org

diff --git a/lib/standard/collection/list.nit b/lib/standard/collection/list.nit
index c9a7155..2cdc431 100644
--- a/lib/standard/collection/list.nit
+++ b/lib/standard/collection/list.nit
@@ -18,7 +18,9 @@ import abstract_collection
 # 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
@@ -124,20 +126,11 @@ class List[E]
 			push(e)
 			return
 		end
-		var nnode = new ListNode[E](e)
-		var next = node.next
-		if next == null then
-			_tail = nnode
-		else
-			next.prev = nnode
-		end
-		nnode.prev = node
-		nnode.next = next
-		node.next = nnode
+		insert_before(e, node)
 	end
 
 	# Append `l` to `self` but clear `l`.
-	##
+	#
 	# O(1)
 	fun link(l: List[E])
 	do
@@ -201,6 +194,7 @@ class List[E]
 
 
 	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
@@ -209,10 +203,10 @@ class List[E]
 	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]
@@ -275,6 +269,7 @@ class ListIterator[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
@@ -286,21 +281,19 @@ class ListIterator[E]
 	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
@@ -315,17 +308,30 @@ class ListIterator[E]
 	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