lib/coll: generalize `insert` in Sequence

[nit.git] / lib / standard / collection / list.nit

diff --git a/lib/standard/collection/list.nit b/lib/standard/collection/list.nit
index 3a59a49..c9a7155 100644 (file)
--- a/lib/standard/collection/list.nit
+++ b/lib/standard/collection/list.nit
@@ -116,6 +116,26 @@ class List[E]
                _head = node
        end
 
+       # O(n)
+       redef fun insert(e, i)
+       do
+               var node = get_node(i)
+               if node == null then
+                       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
+       end
+
        # Append `l` to `self` but clear `l`.
        ##
        # O(1)