From: "nobu (Nobuyoshi Nakada)" <nobu@...>
Date: 2012-05-04T08:50:30+09:00
Subject: [ruby-core:44865] [ruby-trunk - Feature #6361] Bitwise string operations


Issue #6361 has been updated by nobu (Nobuyoshi Nakada).


=begin
:kernigh (George Koehler) wrote:

* The main reason, to perform bitwise operations on a String, is to use this String as an array of bits. The purpose of each bitwise operation is to clear or set some bits in this array. For example, a sieve of Erathosthenes might clear a bit in a String to show that a number is not prime.

What you want seems (({BitArray})), not a kind of char string.

* If String would have bitwise operations, a sieve of Eratosthenes might use them. If String#& and String#~ would exist, then they can clear a bit.
  
   sieve = "\xAC(\x8A\xA2("
   sieve[3] &= ~"\x02"

Isn't (({BitArray})) clearer?

  sieve = BitArray("\xAC(\x8A\xA2(")
  sieve[26] = false
  # or
  sieve.clear(26)

=end


----------------------------------------
Feature #6361: Bitwise string operations
https://bugs.ruby-lang.org/issues/6361#change-26438

Author: MartinBosslet (Martin Bosslet)
Status: Feedback
Priority: Normal
Assignee: 
Category: core
Target version: 


I know this has been discussed a lot in the past (and if there's still 
an open issue for this, I apologize, I couldn't find one), for example
in [1]. While it is generally no problem to implement this on the fly,
I still find that built-in support would be a real improvement. There
are quite some use cases in cryptography where this would come in very
handy, but I'm sure there are lots of other areas, too.

While of course I understand the reasons that were given in the previous
threads that ultimately lead to rejection, I still would like to reopen
the discussion as I felt that in every thread so far the consensus was
that having bitwise string operations would indeed be quite valuable. 

[1] http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-core/34586


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