[#395238] rubygem: ispunity (unite all your internet connections) — Arun Tomar <tomar.arun@...>

Dear friends,

12 messages 2012/05/01

[#395250] Overwriting one Ruby array or arrays with another — Craig Law <lists@...>

Hi

14 messages 2012/05/02

[#395258] array of strings - finding letter combinations — "Sebastjan H." <lists@...>

Hi All,

16 messages 2012/05/02

[#395357] Why Enumerator#next does not return more than one value? — Földes László <lists@...>

If I have an Enumerator which yields elements of a mathematical series

10 messages 2012/05/07

[#395373] How to use Data_Wrap_Struct to assign the DATA VALUE to an exsiting Ruby object? — Iñaki Baz Castillo <ibc@...>

Hi, my code receives an arbitrary klass name (provided by the user)

8 messages 2012/05/07

[#395429] passing via instance variable or regular () — sam jam <lists@...>

def first

10 messages 2012/05/10

[#395463] I'm looking for a Metaprogramming Project — Phil Stone <lists@...>

Hello,

19 messages 2012/05/11

[#395548] A million reasons why Encoding was a mistake — Marc Heiler <lists@...>

Newcomer wants to try Ruby.

15 messages 2012/05/15
[#395561] Re: A million reasons why Encoding was a mistake — Ryan Davis <ryand-ruby@...> 2012/05/15

[#395595] Re: A million reasons why Encoding was a mistake — Brian Candler <lists@...> 2012/05/16

I will add that the OP is not entirely alone in his opinion.

[#395551] How to ensure that a block runs entirely after other threads? (Thread.exclusive does not "work") — Iñaki Baz Castillo <ibc@...>

Hi, I expected that in the following example code, thread t1 would not

8 messages 2012/05/15

[#395575] GUI with ruby on windows — David Acosta <lists@...>

hello friends, i am a begginer and i have a litlle question, how can i

17 messages 2012/05/16

[#395604] what is going wrong here? — roob noob <lists@...>

Notice the initialization of both classes in each of the examples, if

20 messages 2012/05/16

[#395646] rb_gc_register_address() or rb_gc_mark()? — Iñaki Baz Castillo <ibc@...>

Hi, I've bad experiences with rb_gc_register_address(), it does never

16 messages 2012/05/17

[#395686] reading from and writing to a Unicode encoded file — "Sebastjan H." <lists@...>

Hi,

19 messages 2012/05/18
[#395694] Re: reading from and writing to a Unicode encoded file — Regis d'Aubarede <lists@...> 2012/05/18

Hello,

[#395697] Re: reading from and writing to a Unicode encoded file — "Sebastjan H." <lists@...> 2012/05/18

Regis d'Aubarede wrote in post #1061272:

[#395698] Re: reading from and writing to a Unicode encoded file — Regis d'Aubarede <lists@...> 2012/05/18

Sebastjan H. wrote in post #1061276:

[#395699] Re: reading from and writing to a Unicode encoded file — "Sebastjan H." <lists@...> 2012/05/18

Regis d'Aubarede wrote in post #1061277:

[#395750] Re: reading from and writing to a Unicode encoded file - issues when using Shoes — "Sebastjan H." <lists@...> 2012/05/21

Hi,

[#395754] Re: reading from and writing to a Unicode encoded file - issues when using Shoes — "Sebastjan H." <lists@...> 2012/05/21

Sebastjan H. wrote in post #1061483:

[#395740] ? Ruby through CGI and Rails — Shaun Lloyd <list@...>

Hi everybody,

22 messages 2012/05/21
[#395764] Re: Ruby through CGI and Rails — Brian Candler <lists@...> 2012/05/21

Shaun Lloyd wrote in post #1061455:

[#395786] Re: Ruby through CGI and Rails — Shaun Lloyd <list@...> 2012/05/22

On 22/05/12 03:37, Brian Candler wrote:

[#395838] Re: Ruby through CGI and Rails — Brian Candler <lists@...> 2012/05/23

Shaun Lloyd wrote in post #1061602:

[#395787] Changing self class from inside a method?? — David Madison <lists@...>

Let's start off with the assumption I want a method that allows an

10 messages 2012/05/22

[#395841] Memory-efficient set of Fixnums — George Dupre <lists@...>

Hi,

25 messages 2012/05/23

[#395883] looking for a ruby idiom : r=foo; return r if r — botp <botpena@...>

Hi All,

11 messages 2012/05/24

[#395966] Am I justified to use a global variable if it must be used in all scopes? — Phil Stone <lists@...>

Hello,

12 messages 2012/05/27

[#396010] does this leak more than the size of the string via timing side channels — rooby shoez <lists@...>

string1 = "string"

16 messages 2012/05/29

[#396038] Is it possible to avoid longjmp in exceptions, Thread#kill, exit(), signals? — Iñaki Baz Castillo <ibc@...>

Hi, my Ruby C extension runs a C loop (libuv) without GVL. At some

8 messages 2012/05/29

Re: Memory-efficient set of Fixnums

From: Robert Klemme <shortcutter@...>
Date: 2012-05-23 14:40:25 UTC
List: ruby-talk #395854
On Wed, May 23, 2012 at 12:22 PM, George Dupre <lists@ruby-forum.com> wrote:
> I have to:
> 1) generate a database of a couple dozens of millions of Fixnums
> (ranging from 0 to 2^32 - 1), while avoiding redundancy
> 2) iterate through them
> 3) quickly search for the presence of a given Fixnum in the database
>
> The Set class fulfills the speed conditions and conveniently handles
> redundancy itself, but its uses up too much memory. It looks like each
> entry uses up around a 100 bytes, even if I only put 4 bytes in there.
> Array#include? is too slow without solving the memory problem.
> Representing each Fixnum as 4 bytes in a huge String doesn't use up much
> memory at all and String#include? is fast enough, but I can't tell it to
> only search by 4 bytes increments.

You could use a BigNum as bitset.  But that might be slow.  I once
created a BitSet class which uses a String internally for storage.
IIRC that was quite efficient and fast.  I put up an illustrating
example here
https://gist.github.com/2775600

Kind regards

robert

-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/

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