Andrei Alexandrescu wrote:
I have exchanged email with Paul Hsieh about using his hash function in
Phobos (azillionmonkeys.com) and he said his license is very permissive.
I seem to recall I have introduced his hash function, with credit, in
Phobos' old runtime but I am not sure whether Sean
On Sun, 03 May 2009 08:10:43 -0400, Frits van Bommel
wrote:
Jarrett Billingsley wrote:
Here's something bizarre: porting this example to Tango yields 7
unique hashes, which is right in line with your estimate. But I think
it's bizarre since, well, shouldn't druntime use _the same typein
dsimcha Wrote:
> == Quote from Steve Teale (steve.te...@britseyeview.com)'s article
> > Kristian Kilpi Wrote:
> > > On Sun, 03 May 2009 15:33:12 +0300, Jérôme M. Berger
> > > wrote:
> > > > |
> > > > | foreach(c; str)
> > > > | {
> > > > | ret = (ret << 4) + c;
> > > > | }
> > > > |
> > > >
dsimcha wrote:
== Quote from Steve Teale (steve.te...@britseyeview.com)'s article
Kristian Kilpi Wrote:
On Sun, 03 May 2009 15:33:12 +0300, J�r�me M. Berger
wrote:
|
| foreach(c; str)
| {
| ret = (ret << 4) + c;
| }
|
That one is very bad because it only takes into account the las
== Quote from Steve Teale (steve.te...@britseyeview.com)'s article
> Kristian Kilpi Wrote:
> > On Sun, 03 May 2009 15:33:12 +0300, J�r�me M. Berger
> > wrote:
> > > |
> > > | foreach(c; str)
> > > | {
> > > | ret = (ret << 4) + c;
> > > | }
> > > |
> > > That one is very bad because it only
Kristian Kilpi Wrote:
> On Sun, 03 May 2009 15:33:12 +0300, Jérôme M. Berger
> wrote:
> > |
> > | foreach(c; str)
> > | {
> > | ret = (ret << 4) + c;
> > | }
> > |
> > That one is very bad because it only takes into account the last
> > few characters of the string (how many depends on
On Sun, 03 May 2009 15:33:12 +0300, Jérôme M. Berger
wrote:
|
| foreach(c; str)
| {
| ret = (ret << 4) + c;
| }
|
That one is very bad because it only takes into account the last
few characters of the string (how many depends on the size of the
hash). However, several hashing algori
This guy looks to have a pretty good hash function:
http://www.azillionmonkeys.com/qed/hash.html
He matched Bob Jenkins' One-at-a-time hash on a variety of tests and
beat it on speed.
--bb
On Sun, May 3, 2009 at 5:19 AM, Kristian Kilpi wrote:
> On Sun, 03 May 2009 04:59:26 +0300, BCS wrote:
>>
-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1
Kristian Kilpi wrote:
| On Sun, 03 May 2009 04:59:26 +0300, BCS wrote:
|>
|> IIRC something like this is common:
|>
|> hash_t ret = 0;
|> foreach(c;str) { ret *= SomePrime; ret += c; }
|>
|
| I think that's the basis for the best general string hashi
On Sun, 03 May 2009 04:59:26 +0300, BCS wrote:
IIRC something like this is common:
hash_t ret = 0;
foreach(c;str) { ret *= SomePrime; ret += c; }
I think that's the basis for the best general string hashing funcs around.
IIRC from the university, it doesn't matter, in practice, if the
m
Jarrett Billingsley wrote:
Here's something bizarre: porting this example to Tango yields 7
unique hashes, which is right in line with your estimate. But I think
it's bizarre since, well, shouldn't druntime use _the same typeinfo
code?_
No, Tango recently upgraded its hashing algorithms. T
== Quote from bearophile (bearophileh...@lycos.com)'s article
> dsimcha:
> > we first need to fix D's string hashing.<
> Ages ago I did suggest this one in the main D newsgroup:
> http://www.azillionmonkeys.com/qed/hash.html
> Bye,
> bearophile
On second thought...The real problem is just a strang
On Sat, May 2, 2009 at 1:00 PM, dsimcha wrote:
> The result is that only about 8400 unique hashes are used, meaning 90+ % of
> keys cannot be stored directly in the position corresponding to their hash.
> Note that this is in full hash_t space, not in the modulus space typically
> used for AAs, s
== Quote from bearophile (bearophileh...@lycos.com)'s article
> dsimcha:
> > we first need to fix D's string hashing.<
> Ages ago I did suggest this one in the main D newsgroup:
> http://www.azillionmonkeys.com/qed/hash.html
> Bye,
> bearophile
Yeah, upon further reverse engineering, the way strin
dsimcha:
> we first need to fix D's string hashing.<
Ages ago I did suggest this one in the main D newsgroup:
http://www.azillionmonkeys.com/qed/hash.html
Bye,
bearophile
I've been playing around with associative array implementations in D, mostly
trying to create ones that are more GC-friendly. I had written one that
seemed much faster than the builtin for int and float keys but much slower for
strings. I've found the reason: The builtin AAs use trees for collis
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