Michael Tsai on Twitter: "@grynspan I’m not saying it’s a good distribution, just that hash(i) != i."

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Jonathan Grynspan ‏@grynspan 19 Feb 2013

Just double-checked. At least as of SL, CFNumber uses an int as its own hash. Very bad hash distribution on many common kinds of data sets.
Michael Tsai ‏@mjtsai 19 Feb 2013

@grynspan Where do you see that? In the 10.6.8 CF source, I see _CFHashInt() multiplying the int by HASHFACTOR.
Jonathan Grynspan ‏@grynspan 19 Feb 2013

@mjtsai Yes, but the result is still poor distribution. Also negative numbers are given the same hash as their negation.

‏@mjtsai

@grynspan I’m not saying it’s a good distribution, just that hash(i) != i.

6:13 PM - 19 Feb 2013

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