Eric V. Smith <e...@trueblade.com> added the comment:
Here's the simplest way I can describe this, and it's also the table used
inside the code. The column "has-explicit-hash?" is trying to answer the
question "is there a __hash__ function defined in this class?". It is set to
False if either __hash__ is missing, or if __hash__ is None and there's an
__eq__ function. I'm assuming that the __hash__ is implicit in the latter case.
# Decide if/how we're going to create a hash function. Key is
# (unsafe_hash, eq, frozen, does-hash-exist). Value is the action to
# take.
# Actions:
# '': Do nothing.
# 'none': Set __hash__ to None.
# 'add': Always add a generated __hash__function.
# 'exception': Raise an exception.
#
# +-------------------------------------- unsafe_hash?
# | +------------------------------- eq?
# | | +------------------------ frozen?
# | | | +---------------- has-explicit-hash?
# | | | |
# | | | | +------- action
# | | | | |
# v v v v v
_hash_action = {(False, False, False, False): (''),
(False, False, False, True ): (''),
(False, False, True, False): (''),
(False, False, True, True ): (''),
(False, True, False, False): ('none'),
(False, True, False, True ): (''),
(False, True, True, False): ('add'),
(False, True, True, True ): (''),
(True, False, False, False): ('add'),
(True, False, False, True ): ('exception'),
(True, False, True, False): ('add'),
(True, False, True, True ): ('exception'),
(True, True, False, False): ('add'),
(True, True, False, True ): ('exception'),
(True, True, True, False): ('add'),
(True, True, True, True ): ('exception'),
}
PR will be ready as soon as I clean a few things up.
----------
_______________________________________
Python tracker <rep...@bugs.python.org>
<https://bugs.python.org/issue32929>
_______________________________________
_______________________________________________
Python-bugs-list mailing list
Unsubscribe:
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
