0001-Make-connect-4-AI-non-deterministic-in-the-random-se.patch

From b01b0f22245fe5f0d527b31f4150d9c82f18cea2 Mon Sep 17 00:00:00 2001
From: Edd Barrett <vext01@gmail.com>
Date: Fri, 25 Oct 2013 12:49:56 +0100
Subject: [PATCH] Make connect 4 AI non-deterministic (in the random sense).

---
 connect4/connect4.pl | 11 ++++++++++-
 connect4/gui.py      | 10 +++++++++-
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/connect4/connect4.pl b/connect4/connect4.pl
index 9b16136..57ca7bf 100644
--- a/connect4/connect4.pl
+++ b/connect4/connect4.pl
@@ -83,12 +83,21 @@ insert_token(pos(Reds, Yellows, WhoseMove), Col, Move) :-
                          pos(Reds, [c(Col, Y) | Yellows], red),
                          WhoseMove, Move).
 
+% Nasty hack to work around lack of proper list conversion
+% over the language boundary. XXX
+shuffle(In, Out) :-
+    Hack =.. [xxx | In ],
+    python:shuffle_moves(Hack, Shuffled),
+    Shuffled =.. [ _ | Out ].
+
 % Find all possible subsequent game states
 moves(pos(Reds, Yellows, _), []) :- % if someone won, dont collect moves
     has_won(Reds, Yellows, _), !.
+
 moves(Pos, Moves) :-
     board_width(Width), Col is Width - 1,
-    findall(Move, moves(Pos, Move, Col), Moves).
+    findall(Move, moves(Pos, Move, Col), MovesOrdered),
+    shuffle(MovesOrdered, Moves).
 
 moves(pos(Reds, Yellows, WhoseMove), Move, Col) :-
     board_width(W), Col < W, Col > -1,
diff --git a/connect4/gui.py b/connect4/gui.py
index 4c20b3e..75a9a58 100644
--- a/connect4/gui.py
+++ b/connect4/gui.py
@@ -1,9 +1,17 @@
 import Tkinter as tk
-import uni, sys
+import uni, sys, random
 
 ROWS = 6
 COLS = 7
 
+# Since there is no RNG is pyrolog, we let Python shuffle our list
+# XXX No proper list conversion from Prolog, so the list comes in as a
+# n-ary term, which we then shuffle and throw back.
+def shuffle_moves(moves_term):
+    l = list(moves_term)
+    random.shuffle(l)
+    return uni.CoreTerm("xxx", l)
+
 def token_click_closure(c4, colno):
     return lambda : c4._player_turn(colno)
 
-- 
1.8.4