tail calls

• Tricks of the trade: Recursion to Iteration, Part 4: The Trampoline – June 12, 2013
• Tricks of the trade: Recursion to Iteration, Part 3: Recursive Data Structures – June 3, 2013
• Tricks of the trade: Recursion to Iteration, Part 2: Eliminating Recursion with the Time-Traveling Secret Feature Trick – May 14, 2013