Bags with different ranges are different types.

Author: jpivarski

histogrammar/primitives/bag.py

@@ -26,7 +26,7 @@ class Bag(Factory, Container):
 
     A bag is the appropriate data type for scatter plots: a container that collects raw values, maintaining multiplicity but not order. (A "bag" is also known as a "multiset.") Conceptually, it is a mapping from distinct raw values to the number of observations: when two instances of the same raw value are observed, one key is stored and their weights add.
 
-    Although the user-defined function may return scalar numbers, fixed-dimension vectors of numbers, or categorical strings, it may not mix types. Different Bag primitives in an analysis tree may collect different types.
+    Although the user-defined function may return scalar numbers, fixed-dimension vectors of numbers, or categorical strings, it may not mix range types. For the purposes of Label and Index (which can only collect aggregators of a single type), bags with different ranges are different types.
     """
 
     @staticmethod

histogrammar/primitives/collection.py

@@ -256,6 +256,10 @@ def __init__(self, **pairs):
         contentType = list(pairs.values())[0].name
         if any(x.name != contentType for x in pairs.values()):
             raise ContainerException("all Label values must have the same type")
+        if contentType == "Bag":
+            rangeType = list(pairs.values())[0].range
+            if any(x.range != rangeType for x in pairs.values()):
+                raise ContainerException("all Label values must have the same type")
 
         self.entries = 0.0
         self.pairs = pairs
@@ -631,6 +635,10 @@ def __init__(self, *values):
         contentType = values[0].name
         if any(x.name != contentType for x in values):
             raise ValueError("all Index values must have the same type")
+        if contentType == "Bag":
+            rangeType = values[0].range
+            if any(x.range != rangeType for x in values):
+                raise ValueError("all Index values must have the same type")
 
         self.entries = 0.0
         self.values = values