/**
 * ADT: DequeIdea
 * Description: The idea for a Deque structure
 * Notes:
 * 	1) Also see super-ADT
 * 	2) The (inherited) "add" method does an "addLast"
 * 	3) The (inherited) "toNativeList" returns list in first to last order
*/
	
//Super (Parent) ADT: SpecializedStructureIdea (all methods in super are inherited by DequeIdea)

ADT: DequeIdea {
	
	//--------------------- Accessing ---------------------

	/**
	 * Returns first element
	   If list is empty, throws exception:
			"(first) Attempted to access element in empty list"
	 */
	first();
	
	
	/**
	 * Returns last element
	   If list is empty, throws exception:
			"(last) Attempted to access element in empty list"
	 */
	last();
	
	//--------------------- Adding ---------------------

	/**
		* Adds the passed element to start of list
	 */
	addFirst(newElem);
	
	
	/**
	 * Adds the passed element to end of list
	 */
	addLast(newElem);
	
	//--------------------- Removing ---------------------
	
	/**
	 * Removes first element
	 * Returns removed element
	   If list is empty, throws exception:
			"(removeFirst) Attempted to access element in empty list"
	 */
	removeFirst();
	
	
	/**
	 * Removes last element
	 * Returns removed element
	   If list is empty, throws exception:
			"(removeLast) Attempted to access element in empty list"
	 */
	removeLast();
	
}