Chess playing bot (test driven development)

This is a chess playing bot written in Swift.

Here is a summary of it's working principle:

1. It utilizes the well-known minimax algorithm for constructing decision trees.
2. Then it prunes that tree using alpha-beta pruning algorithm.
3. After pruning it traverses that tree, evaluates the highest ranked move and plays it.
4. The depth of decision tree is 2.

Here's a screenshot of the bot playing itself:

Please see the following files for more information:

1. AIPlayer.swift
2. EvaluationValueHandler.swift

Graphical programming is done in Apple's SceneKit framework (used for 3D graphics programming).