Companion

Create an empty BloomFilter for use as a module serialization filter. When populated with the hashes of values that have been created or deserialized for the module, it can be used to quickly determine if an object with a particular hash value is present in the module's objects. At that point, the module's objects can be inverted to form a map from object to index, cached in the module, and a lookup can then take place. Due to the conservative nature of Bloom filters, sometimes the object will not be found even if the filter indicates the value might be present.

Construct a new empty module. Pre-add the module itself to its set of ancestor modules.