From: Minero Aoki <aamine@...>
Date: 2005-11-02T21:13:53+09:00
Subject: ruby-dev summary 27393-27541

Hi all,

This is a summary of ruby-dev #27393-27541.

[ruby-dev:27406] Ripper.new("").parse blocks

  Akira Tanaka reported that Ripper.new("").parse blocks.  This is because:

   1. Ripper.new checks #gets method for the argument.
   2. rb_respond_to() returns true for private methods.
   3. Ripper.new calls String#gets, which is equivalent to private
      method Kernel#gets.
   4. Kernel#gets reads data from $stdin, it blocks.

  To solve this problem, nobu posted a patch to change rb_respond_to()
  behavior, and the patch is incorporated.  Now rb_respond_to() returns
  true only for public methods.

[ruby-dev:27417] selector namespace

  Shugo Maeda proposed a new language feature, "selector namespace".
  Matz also noted this topic in his key note at Ruby Conference 2005.

  Selector namespace is a namespace of selector (method name).  This
  function is useful to replace methods temporarily.  For example,
  current jcode.rb replaces String#chop itself, which effects globally.
  But with selector namespace, it effects only in "jcode" namespace.

    class String
      def jcode$chop   # define #chop method in jcode namespace
        ...
      end
    end

    # "\244\242\244\244" is Japanese characters 'A'+'I' in EUC-JP
    p "\244\242\244\244".chop         # "\244\242\244"  # wrong result
    p "\244\242\244\244".jcode$chop   # "\244\242"      # right result

  You can omit namespace specifier ("jcode$") by using "using" syntax:

    class String
      def jcode$chop() ... end
    end

    using jcode
    p "\244\242\244\244".chop   # "\244\242"      # right result

  There are still many arguments, for example:

    * whether "using" effects statically or dynamically
    * '$' is ugly
    * scope of "using" (file level / module level / method level)
    * whether spaces are allowed around '$'

[ruby-dev:27424] value of BEGIN block

  Nobuyoshi Nakada posted a patch to get a value of BEGIN block, like
  following code:

    val = BEGIN { 2 ** 345 }

  You can utilise this function like `once' method provided by Eiffel
  programming language:

    # p is executed 5000 times but 2**345 is calculated only once
    5000.times do
      p(BEGIN { 2 ** 345 })
    end

  This issue is still open.

[ruby-dev:27449] --without-foo

  Usaku Nakamura posted a patch to add new configure options to select
  compiling extension libraries.  For example, you can disable Win32API
  library and io/wait library by following options:

    $ ./configure --without-Win32API --with-io/wait=no

  This patch is incorporated to CVS trunk HEAD.

[ruby-dev:27470] def Foo::Bar.baz

  Shyouhei URABE claimed that "def Foo::Bar.baz" should be valid:

    ~ % ruby -ce 'def Foo::Bar.baz() end'
    -e:1: syntax error, unexpected '.', expecting ';' or '\n'
    def Foo::Bar.baz() end
                 ^
    -e:1: syntax error, unexpected kEND, expecting $end

  Matz rejected this claim because we cannot add this syntax without
  any (yacc's) conflict.

[ruby-dev:27548] ruby 1.8.4 preview 1 released

  Matz released ruby 1.8.4 preview 1.

  ftp://ftp.ruby-lang.org/pub/ruby/1.8/ruby-1.8.4-preview1.tar.gz
  MD5 sum: cfb6e4c53369c016ebb4061c240c493d


-- Minero Aoki
ruby-dev summary index: http://i.loveruby.net/en/ruby-dev-summary.html