Hi all,
This is a summary of ruby-dev ML in these days.

-------- #17965-18021 (2002-08-09 ...2002-08-16) --------

[ruby-dev:17966] Hash has default block?

  TANAKA Akira has asked that there is a method to determine
  whether a hash has the default block. Matz has proposed a new method
  Hash#default_proc and Akira has agreed.

[ruby-dev:17970] new scope-in-state

  Keiju Ishitsuka has announced his scope-in-state module.
  This module allows you to restrict an effect of
  "destructive" library, such as jcode.rb or mathn.rb.

    # e.g.
    1 / 1       # is 1 (Fixnum)
    MathnScope.scope_in {
        1 / 1   # is Rational(1,1)
    }
    1 / 1       # is 1 (Fixnum)
    
  You can get scope-in-state library from RAA:
  http://www.ruby-lang.org/en/raa-list.rhtml?name=scope-in-state

[ruby-dev:17974] optimization module

  Takaaki Tateishi has announced `optimize' module and
  Matz has suggested it is worth including to the core.

  see also: [ruby-talk:46661] optimization module and tail recursion

[ruby-dev:17965] inferior-ruby-mode and irb

  This thread has occurred synchronizing with ruby-talk:
  [ruby-talk:47113] ruby-mode / inferior ruby.

[ruby-dev:18004] allocation framework

  TANAKA Akira has noted that following code causes segmentation
  fault.

    # pattern 1
    class << Object
      alias obj_allocate allocate
    end
    Hash.obj_allocate   # calls Object.allocate for Hash

    # pattern 2
    class << Hash
      remove_method :allocate
    end
    Hash.allocate   # calls Object.allocate for Hash

    # pattern 3
    class << Object
      alias obj_allocate allocate
    end
    class << Array
      alias allocate obj_allocate
    end
    Array.allocate   # calls Object.allocate for Array

  The purpose of the allocation framework is to get an internal
  structure of instances from the class (e.g. struct RObject for Object).
  Currently CLASS.allocate works for it, but it is too easy to
  modify class methods from Ruby programs.  Result: Ruby programs
  will become very weak.

  Matz has said that we must reconsider allocation framework itself.

-- Minero Aoki