registtro 0.2.1

Weak entry, strong value immutable registry data structure

Overview

Registtro provides a weak entry, strong value immutable registry data structure. Think of it as an immutable WeakKeyDictionary.

Example

>>> from registtro import Registry
>>> class Entry:
...     pass
...
>>> # Initialize registry with 2 entries.
>>> entry_a = Entry()
>>> entry_b = Entry()
>>> registry = Registry({entry_a: 1, entry_b: 2})
>>> registry.query(entry_a)
1
>>> # Update a value and add a new entry, retrieve new registry (immutable).
>>> entry_c = Entry()
>>> registry = registry.update({entry_a: 10, entry_c: 3})
>>> registry.query(entry_a)
10
>>> registry.query(entry_c)
3
>>> # Get evolver and perform updates on it (mutable).
>>> evolver = registry.get_evolver()
>>> evolver.update({entry_b: 20})
<registtro.RegistryEvolver object at ...>
>>> evolver.update({entry_c: 30})
<registtro.RegistryEvolver object at ...>
>>> evolver.query(entry_c)
30
>>> # Freeze evolver into a registry (immutable).
>>> registry = evolver.get_registry()
>>> registry.query(entry_c)
30