Feature/weak diversions

[simonsben]

0.2.0

• feature: support for weak diversion variants
  • a weak variant allows it to be caught by normal try-catches when using except Exception:

[lilatomic]

one weakness with dynamically creating this class is that it is unique every time make_weak is called.
given:

>>> def f():
...     class C(Exception): ...
...     return C
>>> A = f()
>>> B = f()
# If the same instance is used:
>>> try:
...     raise A()
... except A:
...     pass
>>>
# if a different instance is used:
>>> try:
...     raise A()
... except B:
...     pass
... 
Traceback (most recent call last):
  File "<stdin>", line 2, in <module>
__main__.f.<locals>.C

You can get around this by caching the result of this function (though be careful to access the value on the class itself)

>>> class E(Exception):
...     weakened = None
...     @classmethod
...     def make_weak(cls):
...             if cls.weakened is None:
...                     class Weakened(cls, Exception): ...
...                     cls.weakened = Weakened
...             return cls.weakened
>>> A = E.make_weak()
>>> B = E.make_weak()
>>> try:
...     raise A()
... except B:
...     pass
>>>

[simonsben]

True, ya, good call

[lilatomic]

ok hear me out instead of doing this you have a metaclass that generates this exactly once. It's so much machinery for about no payoff

[lilatomic]

while we're on the subject of dumb ways to implement this, how about the 3-arg form of type?

Weakened = type('Weakened', (Diversion, Exception,), {})

[lilatomic]

creating it inline also means that the classname is a little goofy. You can fix that by assigning to both __name__ and __qualname__ of the class

[lilatomic]

you could also make this a separate WF and trigger it only on main

[simonsben]

Ya, I think I like how this logically groups it though, keeps the related things together