move code around to avoid dependency loops

extras/pointers.py

@@ -0,0 +1,15 @@
+""" Various functions related to pointer and address math. Mostly to avoid
+    depedency loops.
+"""
+
+def calculate_pointer(short_pointer, bank=None):
+    """calculates the full address given a 4-byte pointer and bank byte"""
+    short_pointer = int(short_pointer)
+    if 0x4000 <= short_pointer <= 0x7fff:
+        short_pointer -= 0x4000
+        bank = int(bank)
+    else:
+        bank = 0
+    pointer = short_pointer + (bank * 0x4000)
+    return pointer
+