Jeroen Demeyer <[email protected]> added the comment:
To come back to the topic of hashing, with "Bernstein hash" for tuples I did
indeed mean the simple (in Python pseudocode):
# t is a tuple
h = INITIAL_VALUE
for x in t:
z = hash(x)
h = (h * MULTIPLIER) + z
return h
I actually started working on the code and there is indeed an issue with the
hashes of (X, (Y, Z)) and (Y, (X, Z)) being equal that way. But that can be
solved by replacing "hash(x)" in the loop by something slightly more
complicated. After thinking about it, I decided to go for shifting higher to
lower bits, so replacing z by z^(z >> 32) or something like that.
This also has the benefit of mixing the high-order bits into the low-order
bits, which is an additional improvement over the current code.
Since I already wrote the code anyway, I'll create a PR for it.
----------
_______________________________________
Python tracker <[email protected]>
<https://bugs.python.org/issue34751>
_______________________________________
_______________________________________________
Python-bugs-list mailing list
Unsubscribe:
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
