Queue.mon

package com.apamax.containers;

/**
 * A First-In-First-Out queue object.
 */
event Queue
{
	/** Create an empty queue. */
	static action create() returns Queue
	{
		return new Queue;
	}
	/** Push a value onto the back of the queue. 
	 * @param val The value to add to the queue.
	 */
	action push(any val)
	{
		data.append(val);
	}
	/** Remove and return the value on the front of the queue. */
	action pop() returns any
	{
		any val := data[0];
		data.remove(0);
		return val;
	}
	/** Return the front value on the queue without removing it. */
	action peekNext() returns any
	{
		return data[0];
	}
	/** Return the number of items in the queue. */
	action size() returns integer
	{
		return data.size();
	}
	/** Return true if the queue is empty. */
	action empty() returns boolean
	{
		return data.size()=0;
	}
	/** Remove all the contents of the queue. */
	action clear()
	{
		data.clear();
	}

	/** @private */
	sequence<any> data;
}