>head</b>()</code> alias for <code>first()</code></li>
					<li><code><b>tail</b>()</code> alias for <code>last()</code></li>
				</ul>
			</dd>
		</dl>
	</li>
	
</ul>

<h2>Examples</h2>

<h3><a name="GraphSearch">Broad-first and depth-first searches for directed graphs.</a></h3>

<pre>
local oo         = require "loop.base"
local OrderedSet = require "loop.collection.OrderedSet"

local function inbroad(queue, head)
  head = queue[head]
  if head then
    for _, node in ipairs(head) do
      queue:enqueue(n