Time for an 2014 update…

Task/Sorting-algorithms-Cocktail-sort/Ruby/sorting-algorithms-cocktail-sort-1.rb

@@ -8,7 +8,7 @@ class Array
           swapped = true
         end
       end
-      break if not swapped
+      break unless swapped
 
       swapped = false
       (length - 2).downto(0) do |i|
@@ -21,6 +21,3 @@ class Array
     self
   end
 end
-ary = [7,6,5,9,8,4,3,1,2,0]
-ary.cocktailsort!
-# => [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

Task/Sorting-algorithms-Cocktail-sort/Ruby/sorting-algorithms-cocktail-sort-2.rb

@@ -0,0 +1,17 @@
+class Array
+  def cocktailsort!
+    start, finish, way = 0, size-1, 1
+    loop do
+      swapped = false
+      start.step(finish-way, way) do |i|
+        if (self[i] <=> self[i + way]) == way
+          self[i], self[i + way] = self[i + way], self[i]
+          swapped = i
+        end
+      end
+      break unless swapped
+      start, finish, way = swapped, start, -way
+    end
+    self
+  end
+end

Task/Sorting-algorithms-Cocktail-sort/Ruby/sorting-algorithms-cocktail-sort-3.rb

@@ -0,0 +1,4 @@
+ary = [7,6,5,9,8,4,3,1,2,0]
+p ary.cocktailsort!
+ary = ["John", "Kate", "Zerg", "Alice", "Joe", "Jane"]
+p ary.cocktailsort!