Merge pull request kodecocodes#77 from andela-aonawale/refactor-LinkedList

Refactor linked list to make the code more Swift-like

Author: hollance

Linked List/LinkedList.swift

@@ -158,10 +158,10 @@ extension LinkedList: CustomStringConvertible {
 extension LinkedList {
   public func reverse() {
     var node = head
-    while node != nil {
-      swap(&node!.next, &node!.previous)
-      head = node
-      node = node!.previous
+    while let currentNode = node {
+        swap(&currentNode.next, &currentNode.previous)
+        head = currentNode
+        node = currentNode.previous
     }
   }
 }

Linked List/README.markdown

@@ -465,9 +465,7 @@ This loops through the entire list and simply swaps the `next` and `previous` po
 	 nil <---|        |--->|        |--->|        |--->|        |<--- head
 	         +--------+    +--------+    +--------+    +--------+
 
-You may be wondering why the last statement says `node = node!.previous` to go to the next node instead of `node!.next` like you'd expect, but remember that we just swapped those pointers!
-
-> **Note:** I couldn't find a way to make this code more Swift-like, without the forced unwrapping. Suggestions for improvements are welcome!
+You may be wondering why the last statement says `node = currentNode.previous` to go to the next node instead of `currentNode.next` like you'd expect, but remember that we just swapped those pointers!
 
 Arrays have `map()` and `filter()` functions, and there's no reason why linked lists shouldn't either.