Next NetBeans is decided to omit RoR Support

NetBeans community decides to omit Ruby on Rails Support, unfortunately.

http://netbeans.org/community/news/show/1507.html

But, NetBeans community will continues only the support for ruby-lang.

Now is the time to switch my ruby IDE to redcar?

LibreOffice repositories for openSUSE

A few days ago, LibreOffice 3.3.0 final has been released. And this release is equivalent with LibreOffice 3.3.0 RC4. openSUSE is already preparing LibreOffice repositories.

http://download.opensuse.org/repositories/LibreOffice:/

For instance, the repository of openSUSE 11.3 is here:

http://download.opensuse.org/repositories/LibreOffice:/Unstable/openSUSE_11.3/
(Update on 2011/02/05)
http://download.opensuse.org/repositories/LibreOffice:/Stable/openSUSE_11.3/

"sqlite3-ruby" had been renamed to "sqlite3"

The library name "sqlite3-ruby" had been renamed to "sqlite3". We should replace from "sqlite3-ruby" to "sqlite3" on our own RubyGems.

If your platform is MinGW(Windows) like this enrty, please check below:

> gem uninstall sqlite3-ruby
> gem install sqlite3 --platform=ruby -- --with-sqlite3-dir=C:/sqlite3

Studying F# : Map

I wrote this post : phosphorescence: Studying F# : Dictionary (a.k.a. Hash or Map). But it is incorrect. Map is there! Map must be created by using List, Tuple and the function Map.ofList.

Microsoft (R) F# 2.0 Interactive build 2.0.0.0
Copyright (c) Microsoft Corporation. All Rights Reserved.

For help type #help;;

> let map_1 = Map.ofList[ (1, "one"); (2, "two"); (3, "three"); (4, "four") ];;

val map_1 : Map<int,string> =
  map [(1, "one"); (2, "two"); (3, "three"); (4, "four")]

Install F# PowerPack on Mac OS X

Operation below is obsolete. Please check phosphorescence: Easier way to install F# PowerPack both on Mac OS X and on Linux.

F# PowerPack is additional libraries for F#. If you are using F# on Windows, you just download and install with .msi installer. But if you are using F# on Mac OS X, let's check these instructions after phosphorescence: Install F# on Mac OS X:

Studying F# : Sequence

F#'s Sequence (seq{ }) instantiates "The way to generate sequential values", not sequential values themselves. The corresponding paradigm in Ruby 1.9 can be implemented with Enumerator. Let's check each codes.

In F#

open System
let oneUptoTen = seq {
    for i = 1 to 10 do
        Console.WriteLine("{0} is generated", i)
        yield i
}
let oneUptoTenEnum = oneUptoTen.GetEnumerator()
while oneUptoTenEnum.MoveNext() do
    Console.WriteLine(oneUptoTenEnum.Current)

In Ruby 1.9

one_upto_ten = proc { |yielder|
  1.upto(10) do |i|
    puts "#{i} is generated"
    yielder << i
  end
}
one_upto_ten_enum = Enumerator.new(&one_upto_ten)
loop do
  puts one_upto_ten_enum.next
end

Outputs are below:

1 is generated
1
2 is generated
2
3 is generated
3
4 is generated
4
5 is generated
5
6 is generated
6
7 is generated
7
8 is generated
8
9 is generated
9
10 is generated
10

JRuby for Windows users or for Non-western languages

Three days ago, JRuby 1.6.0 RC1 has been released. IMHO, this release means "JRuby for the rest of the OSS-develop world". Where is the rest of the OSS-develop world? It's in two areas.

• Windows users
• Non-western languages

F#'s Option nearly equals with C#'s Nullable types

If you have a experience writing Java programs, you would have thought that you want to put null value into primitive variables, at least once. In C#, you can do it with "Nullable types":

// bool
bool? nb = true; // you can set true,
nb = false; // false,
nb = null; // and null

// int
int? ni; // You can set zero,
ni = -1; // non-zero,
ni = null; // and null

In F#, the language on the .NET, You can also deal with same paradigm as "Option".

$ fsharpi

Microsoft (R) F# 2.0 Interactive build 2.0.0.0
Copyright (c) Microsoft Corporation. All Rights Reserved.

For help type #help;;

> let nothing : string option = None;;

val nothing : string option = None

> let something : string option = Some "Hello World";;

val something : string option = Some "Hello World"

> let puts str = System.Console.WriteLine(str.ToString());;

val puts : 'a -> unit

> Option.iter puts something;;
Hello World
val it : unit = ()
> Option.iter puts nothing;;  
val it : unit = ()

Ruby 1.9.2 p136 was released

In 2010/12/25, Ruby 1.9.2 p136 was released. So I download from here, and re-install it like this entry. Let's check.

> /opt/ruby-1.9.1/bin/ruby --version
ruby 1.9.2p136 (2010-12-25 revision 30365) [i686-linux]

But, You should not upgrade RubyGems from this version (1.3.7) to upper version (1.4.0, 1.4.1, 1.4.2 and so forth) because of these reasons (reason 1, reason 2).