Add transfer() utility function.

1 files changed, 23 insertions, 0 deletions

diff --git a/weatbag/utils.py b/weatbag/utils.py
new file mode 100644
index 0000000..0f73294
--- /dev/null
+++ b/weatbag/utils.py
@@ -0,0 +1,23 @@
+"""Utility functions for the game."""
+
+def transfer(item, from_collection, to_collection, n=1):
+    """Move an item from one dictionary of objects to another.
+    
+    Returns True if the item was successfully transferred, False if it's not in
+    from_collection.
+    
+    For example, to have the player pick up a pointy stick::
+    
+        if transfer('pointy stick', tile.contents, player.inventory):
+            print("You take the stick.")
+        else:
+            print("There's no stick here.")
+    """
+    if from_collection.get(item, 0) < n:
+        return False
+    from_collection[item] -= n
+    if item in to_collection:
+        to_collection[item] += n
+    else:
+        to_collection[item] = n
+    return True