Summer vacation 2012, and more...

I take a summer vacation, and, I take a study for the IPA Examination in this October.

So I suspend posts to this blog until this October.

PC-BSD starts to distribute rolling release based on FreeBSD 9.2

PC-BSD starts to distribute rolling release "PC-BSD 9.2 beta".

Rolling-Release and 9.2-BETA1 Released

This is based on FreeBSD 9.2 beta. and its ISOs and images are available in here.

A book for Qt Quick will be also published in Japan.

In last year, a book for Qt Quick had been published in China.
http://www.amazon.com/dp/7512407815/

And in this year, another one will be also published in Japan.
http://ascii.asciimw.jp/books/books/detail/978-4-04-891512-0.shtml

Regular Expression in F#

Regular Expression in F# is used with Active pattern, in most cases.

open System.Text.RegularExpressions
let (|Matcher|_|) pattern input =
  let matcher = Regex.Match(input, pattern)
  if matcher.Success then Some (List.tail [ for group in matcher.Groups -> group.Value ])
  else None
let matchHttpUrl target =
  match target with
    | Matcher @"(https?:\/\/\S+)" result -> Some(result.Head)
    | _ -> None

> matchHttpUrl "http://www.google.com";;
val it : string option = Some "http://www.google.com"
> matchHttpUrl "https://www.google.com";;
val it : string option = Some "https://www.google.com"
> matchHttpUrl "ftp://www.google.com";;
val it : string option = None

ISOs and images for PC-BSD's rolling release have been re-deployed

ISOs and images for PC-BSD's rolling release have been re-deployed in here.

"Strong parameters" is for controlling mass assignment, not for validation.

Since rails4, controller has new feature called "strong parameters".

rails/strong_parameters

"strong parameters" is an alternative for controlling mass assignment. The original ones are known as attr_accessible and attr_protected on ActiveRecord/ActiveModel until rails3. But, because of "Mass Assingment Vulnerability(CVE-2012-2055)" in last year, these features are considered they should be on controller, should not be on ActiveRecord/ActiveModel. So that "strong parameters" begins.

And, the most important thing is, -"strong parameters" is JUST for controlling mass assignment, not for validation-. ActiveRecord/ActiveModel still have their own (and well known) validation features. that's natural because ActiveRecord/ActiveModel is not only used from Web (controllers) but also from non-Web (batches).

Calculate the firefox year with using Seq.unfold #2

(continued from phosphorescence: Calculate the firefox year with using Seq.unfold)

To refine more readable, adapt Active Pattern.

open System
let (|IsBetweenDate|) (targetDate, currentDate, nextDate) =
  (DateTime.Compare(targetDate, currentDate)>0, DateTime.Compare(targetDate, nextDate)>0)
let firefoxRollingReleaseDate n =
  let firefox5ReleaseDate = new DateTime(2011, 6, 21)
  let firefox6ReleaseDate = firefox5ReleaseDate.AddDays(7.0 * 8.0)
  let firefoxRollingRelease (currentDate:DateTime, nextDate:DateTime) =
    match (new DateTime(2012, 12, 25), nextDate, nextDate.AddDays(7.0 * 6.0)) with
    | IsBetweenDate (true, false) -> Some(currentDate, (nextDate, nextDate.AddDays(7.0 * 7.0)))
    | IsBetweenDate _ -> Some(currentDate, (nextDate, nextDate.AddDays(7.0 * 6.0)))
  match n < 5 with
  | true -> failwith "The version was not yet in rolling release."
  | _ -> Seq.nth (n - 5) <| Seq.unfold firefoxRollingRelease (firefox5ReleaseDate, firefox6ReleaseDate)

ISOs and images for PC-BSD's rolling release have been erased.

All packages and binaries for PC-BSD have been switched from mirrors sites to Contents Delivery Network (e.g. BitTorrent).
PC-BSD Now Uses a CDN

But, ISOs and images for PC-BSD's rolling release have also been erased, so that the site http://mirrors.isc.org/pub/pcbsd/9.1-RELEASE/ is now "404 - Not Found".

The information above is now obsoleted. Please check current information:
phosphorescence: ISOs and images for PC-BSD's rolling release have been re-deployed

Qt 5.1 and QtCreator 2.7.2 have been released

Today, Qt 5.1 and QtCreator 2.7.2 have been released

As you can see in download page, there are many binaries, especially, for Windows.

Calculate the firefox year with using Seq.unfold

(Check also phosphorescence: Calculate the firefox year #2 and phosphorescence: Calculate the firefox year #2 (Fixed))
In this article, rewrite with using Seq.unfold . It becomes quite simple architecture.

open System
let firefoxRollingReleaseDate n =
  let firefox5ReleaseDate = new DateTime(2011, 6, 21)
  let firefox6ReleaseDate = firefox5ReleaseDate.AddDays(7.0 * 8.0)
  let isBetweenDate(targetDate:DateTime, currentDate:DateTime, nextDate:DateTime) =
    match (DateTime.Compare(targetDate, currentDate)>0, DateTime.Compare(targetDate, nextDate)>0) with
    | (true, false) -> true
    | (_, _) -> false
  let firefoxRollingRelease (currentDate:DateTime, nextDate:DateTime) =
    match isBetweenDate(new DateTime(2012, 12, 25), nextDate, nextDate.AddDays(7.0 * 6.0)) with
    | true -> Some(currentDate, (nextDate, nextDate.AddDays(7.0 * 7.0)))
    | _ -> Some(currentDate, (nextDate, nextDate.AddDays(7.0 * 6.0)))
  match n < 5 with
  | true -> failwith "The version was not yet in rolling release."
  | _ -> Seq.nth (n - 5) <| Seq.unfold firefoxRollingRelease (firefox5ReleaseDate, firefox6ReleaseDate)

(continue to phosphorescence: Calculate the firefox year with using Seq.unfold #2)

Rails 4 final has been released.

In yeasterday, Ruby on Rails 4.0 final has been released. And agile web development with Rails(a.k.a. AWDwR) also becomes ready for Rails 4.0.

Npgsql's status for supporting EntityFramework

In this article (Npgsql Code First Entity Framework 4.3.1 Sample), I have learned that the current version of Npgsql - PostgreSQL's .NET Driver - only supports EntityFramework4, NOT supports EntityFramework5. And it the next article (Initial EF-6 support added to Npgsql), the next version of npgsql will support EntityFramework6 (may support EntityFramework5).

Tips while freebsd-update

1. Before freebsd-update fetch

If there is no /boot/GENERIC file,

# cd /boot
# ln -s /usr/src/sys/amd64/conf/GENERIC .

2. Before freebsd-update install

Do mergemaster command.

I've finished reading "Refactoring: Ruby Edition"

Since this post, it has taken 17 months because I read it slowly with doing another coding or reading another book.

Fortunately, I have already done most of refactoring examples. But these three examples are not, so that this book is useful for me.

• Introduce Class Annotation
• Replace Type Code with State/Strategy
• Introduce Expression Builder

QtProject provides out-of-the-box MinGW sources and binaries

QtProject provides out-of-the-box MinGW sources and binaries in here.

It contains also OpenSSL binaries and ICU binaries.

How to upgrade msysGit full

If you use msysGit full installer and want to upgrade from old one, there are two points to be noted.

1. rename or remove bin/git.exe
2. rename or remove git/git.exe

Opera changes its rendering engine to Blink, but bookmark goes away

Opera Next 15 and Opera for Android change these endering engine to Blink, but these bookmark go away. So here comes the site to survey features to be back.

• Sound off! What are the top 3 missing things from the new Opera?

Install Opscode Chef with Ruby 2.0 on FreeBSD Ports Collection

Opscode Chef version 10.x depends on JSON rubygem between 1.4.4 and 1.7.7. But, there are two points to solve:

• Ports collection's rubygem-json146 does not support Ruby 2.0
• The newest version of Ports collection's rubygem-json is 1.8.0

So that we must be some operations for install chef

1. cd /usr/ports/devel/rubygem-json
2. Install and do ports-mgmt/portdowngrade to downgrade to 1.7.7
   (or edit Makefile directly to write version 1.7.7)
3. make install
4. cd /usr/ports/sysutils/rubygem-chef
5. edit Makefile
   rubygem-json>=1.4.4:${PORTSDIR}/devel/rubygem-json146 \ to rubygem-json>=1.4.4:${PORTSDIR}/devel/rubygem-json \
6. make install

At last operation, ports collection fails because of rdoc, but Chef rubygem itself are succeeded.

The way to install sqlite3 gem on Ruby 2.0 on Windows

Until Ruby 1.9.3, the way to install sqlite3 gem on Windows is easy - just do gem install. But, since Ruby 2.0, it becomes a difficult way. The solution is written in this article, and this is the only one article at this moment.

• How do I install sqlite3 for Ruby on Windows?

F# Sequence for Collatz Problem

F# Sequence for Collatz Problem is:

let collatzSeq n =
  let collatzFunction n =
    match n % 2L with
    | 0L -> n / 2L
    | _ -> 3L * n + 1L
  let rec collatzCalc n accum =
    let accum'next = Seq.append accum <| Seq.singleton n
    if n = 1L then
      accum'next
    else
      collatzCalc <| collatzFunction n <| accum'next
  match n > 0L with
  | true -> collatzCalc n Seq.empty<int64>
  | _ -> failwith "The argument should be a natural number."

> collatzSeq 1L;;
val it : seq<int64> = seq [1L]
> collatzSeq 2L;;
val it : seq<int64> = seq [2L; 1L]
> collatzSeq 3L |> Seq.toList;;
val it : int64 list = [3L; 10L; 5L; 16L; 8L; 4L; 2L; 1L]
> collatzSeq 4L |> Seq.toList;;
val it : int64 list = [4L; 2L; 1L]
> collatzSeq 5L |> Seq.toList;;
val it : int64 list = [5L; 16L; 8L; 4L; 2L; 1L]
> collatzSeq 6L |> Seq.toList;;
val it : int64 list = [6L; 3L; 10L; 5L; 16L; 8L; 4L; 2L; 1L]
> collatzSeq 7L |> Seq.toList;;
val it : int64 list =
  [7L; 22L; 11L; 34L; 17L; 52L; 26L; 13L; 40L; 20L; 10L; 5L; 16L; 8L; 4L; 2L; 1L]