PUBLIC MARKS with tags library & gameai

APHID is an acronym for Asycnhronous Parallel Hierarchical Iterative Deepening. The APHID game-tree search algorithm attempts to accomplish many goals: * to test out the viability of asynchronous search methods for parallel alpha-beta based search. * to develop an algorithm that works well across all hardware platforms and applications. * to implement a tool that can be easily inserted into legacy sequential search algorithms.

In this paper, an implementation of "Stackless Python" (a Python which does not keep state on the C stack) is presented. Surprisingly, the necessary changes affect just a small number of C modules, and a major rewrite of the C library can be avoided. The key idea in this approach is a paradigm change for the Python code interpreter that is not easy to understand in the first place. Recursive interpreter calls are turned into tail recursion, which allows deferring evaluation by pushing frames to the frame stack, without the C stack involved.