Add extra functions.

1 files changed, 24 insertions, 0 deletions

diff --git a/snakegame/common.py b/snakegame/common.py
index a44219b..92d0e62 100644
--- a/snakegame/common.py
+++ b/snakegame/common.py
@@ -1,3 +1,4 @@
+import random
 from string import ascii_lowercase as lowercase, ascii_uppercase as uppercase
 alphabet = lowercase + uppercase
 
@@ -58,3 +59,26 @@ def get_cell(board, x, y, wrap=True):
     elif not in_bounds(x, y, width, height):
         return None
     return board[y][x]
+
+def get_neighbours(x, y, width, height):
+    for d, (dx, dy) in directions.iteritems():
+        nx = (x + dx) % width
+        ny = (y + dy) % height
+        yield d, nx, ny
+
+def max_items(items, alpha=1.0):
+    """
+    >>> max_items([(1, 'a'), (2, 'b'), (2, 'c'), (0, 'd')])
+    [(2, 'b'), (2, 'c')]
+    """
+    max_score, _ = max(items)
+    return [
+        (score, item)
+        for score, item in items
+        if score >= max_score * alpha
+    ]
+
+def choose_move(choices, default='U', random=random):
+    if not choices:
+        return default
+    return random.choice(choices)