俄罗斯设计师lambda图标设计作品欣赏。

 La Verticale by Lambda

2009 (1 tracks, 3:38)

pop

Many of you have probably heard of the FizzBuzz challenge:

Jeff Atwood blogged about it here

I think it started from here

Anyway, if you don’t want to click those links and you’re not familiar with it, is a small programming problem designed to screen someone who can actually write code from someone who pretends to write code.  The problem is:

Write a program that prints the numbers from 1 to 100. But for multiples of three print “Fizz” instead of the number and for the multiples of five print “Buzz”. For numbers which are multiples of both three and five print “FizzBuzz”

The point is this is a simple problem.  Just simple enough to be interesting.  I actually got asked to solve this problem this week.  I solved it after bumbling through it way more than I should have (I was trying to think of an elegant solution on the spot.)  But it kept bugging me.  I knew there was a solution that I wanted to give it that would make me happy with feelings of maps, function pointers and linq.  Pretty much 3 of my favorite things.  So I thought about it for a bit and here is the solution I came up with (3rd cut.)

        public static void FizzBuzz()
        {
            Dictionary<Func<int, bool>, Func<int, string>> rules = new Dictionary<Func<int, bool>, Func<int, string>>();
            rules.Add(x => x % 3 == 0, x => "fizz");
            rules.Add(x => x % 5 == 0, x => "buzz");
            rules.Add(x => x % 5 != 0 && x % 3 != 0, x => x.ToString());
            rules.Add(x => true, x => "\n");

            var output = from n in Enumerable.Range(1, 100)
                         from f in rules
                         where f.Key(n)
                         select f.Value(n);

            output.ToList().ForEach(x => Console.Write(x));
        }

That’s my crack at it. If you’re not familiar with all the C# magic going on here, basically it works like this:

You have a map which maps one lambda expression which defines the rule we are checking for to a second lambda expression which is what string to return if that rule matches.
Then we have a LINQ query that does a Cartesian join on the set of numbers from 1 to 100 and the 4 rules.
Finally, we take the output and for each string we write it out.

The 4th rule in the set makes sure that after evaluating the set of rules for each number a newline gets put in.

It is kind of interesting how thinking about different ways to solve a fairly simple problem can help you think about the tools you have in new ways.

www.endhivaids.com: Uniting the World Against HIV/AIDS

With its goal to help in the effort to find a cure for the HIV/AIDS virus, Joe Stern-McGovern, global agent and President of Universal Artists, International, has announced the coming force in the world of music, Black Flock Gang’s, music downloads available exclusively at the future site created for charity, knowledge, and understanding, www.endhivaids.com.

In a quote from the Universal Artists, International leader, Joe Stern-McGovern states, “We’re attempting to show our support for the global organizations and leaders who are doing all they can to thwart the HIV/AIDS virus through financial contributions gathered through the sale of our products.”

www.endhivaids.com: Download to Donate

Who are the most likely to receive these funds? Various clinical research organizations such as AMFAR, those which serve to better the lives of children suffering from the virus, such as the Elizabeth Glaser Pediatric AIDS Foundation, St. Judes, and Children’s Hospital, Gay & Lesbian health activists, legal heavyweights such as the ACLU and LAMBDA, and many others.

“We’re trying to put as much money towards the cause as we can,” states Joe Stern-McGovern, “and at the same time gather the means to continue in the various parts involved in making this movement a success, such as site fees, advertising, and other related expenses.”

How will the movement of Joe Stern-McGovern and Universal Artists, International fare, only time will tell, but with the power of the Southern force known as Shaka Productions of Birmingham, Alabama, and his vanguard of soldiers, Black Flock Gang, also known as BFG, chances for success lean towards the more positive end of the spectrum.

“The BFG is a statistics breaker,” states Joe Stern-McGovern, “it’s sheer genius and momentum will shatter all previously conceived measures of success in the charts and through word of mouth.”

Shaka & A-Dub: Uniting to End HIV/AIDS

A bold statement indeed, but having heard the material ourselves, we tend to agree with this icon known as Joe Stern-McGovern, a figure given towards brash statements and bravado in what some might consider a Ted Turner-esque sort of manner.

Black Flock Gang, consisting of Dem Hard Headz, DO and Pain, coupled with the FAM Boy$, Ms. Fame, Facts, Lo, CO, and the ambitious Mr. Hood Shuttlesworth, will burst out of the gate with their smash follow up to the, “Welcome 2 da Bams”, album in a second entrance into the market with the album simply titled, “Radio”. “Radio”, a compilation of BFG, Ms. Fame, and Jacksonville’s artful brothers, Ripp & Redd, is the first in a series of charitable material which has come to be known as, World Mixtape.

Ripp & Redd: Donating Talent for a Great Cause

What is a Mixtape many ask? In reality, it’s a CD compilation of various hip hop’s future stars joining to hop onto what are largely the beats of other artists of prominence. In the case of Universal Artists, International, all their material is original, however, the element they share with the mixtape phenomenon is the mustering of street credibility, outspoken and haughty declarations, and a supreme sense of one’s self coupled with the factors of authenticy and believability.

Black Flock Gang: Download to Donate

Sharing part on the follow up mixtape to Radio, BFG will be joined by the sultry sounds of Ms. Kesha Lee, as well as the lyrically headstrong, Christian Levi, both hailing from Birmingham, Alabama. Reports from the field are that both Ms. Kesha Lee and Christian Levi are poised for their breakouts as solo artists, something all fans of hip hop and R&B are avidly waiting for courtesy of Joe Stern-McGovern, Shaka Productions, and Universal Artists, International.

If all of this wasn’t enough, all material from the World Mixtapes have been finalized by Seattle’s very own, multi-platinum producer, DJ Funk Daddy. Known throughout the Emerald City and the greater Pacific Northwest, DJ Funk Daddy has worked with the very best, and continues his artesan’s tradition on the turntables and microphone with adept skill and dedication to the true nature of hip hop. For more information on DJ Funk Daddy, please visit his site at, www.funkdaddy.com.

The ultimate winner in all these endeavours of Joe Stern-McGovern, Shaka Productions and his artists, and DJ Funk Daddy, are the fans who all hope will download to donate in the most generous of fashion. They are what makes the industry what it is, as well as creating the impetus for where it is headed. After all, without its fans, how far could any genre go?

DJ Funk Daddy: Doing His Part Against HIV/AIDS

Please look for the coming site, www.endhivaids.com sometime in mid-January, where you will delight to the smooth sounds, thumping bass, and articulations of the likes of the BFG as they reflect on the need for awareness, education, and a cure through their music and the contribution it’s expected to generate.

For more information, please write to joesternmcgovern@myspace.com, universalartists@myspace.com, or blackflockgang@myspace.com.

To book an appearance or any other scheduling matters, please feel free to write directly to Joe Stern-McGovern’s assistant at, joe@universalartists.net. For matters of production and A&R, Shaka Productions can be reached at shaka@universalartists.net. For international correspondence, please refer to the company address for Joe Stern-McGovern, or write to Guy at guy@universalartists.net. You may also call us at 1(619)757-1301.

Look for information and updates coming soon regarding the South’s definitive hip hop instrumentalist, A-Dub of Tiptonville, Tennessee, as well as his partner on the microphone, Lake County’s Lil’ J. 

A-Dub: The Best at What He Does

“Together,” states Joe Stern-McGovern, “we can defeat this plague. It’s Universal Artists, International and Shaka Productions sincerest intention to do so in the most powerful and accomplishing manner.”

Again, please look for the Black Flock Gang’s greatest material, past and present, exclusively at www.endhivaids.com. Your patronage and donations are greatly appreciated.

I just ran into a very nice article about using Lambda’s/LINQ on SharePoint objects.
You can find it here.

Working constantly with LINQ and .NET 3.5 these days, I sometimes forget how to do things without lamda expressions. Today, I was working on a WinForms application and I needed to update the UI from a separate thread, so I wrote the following code:

    this.BeginInvoke( ()=>
        {
            //code to update UI
        });

This gave me the following error:

Cannot convert lambda expression to type 'System.Delegate' because it is not a delegate type

I, then tried the anonymous delegate syntax:

    this.BeginInvoke( delegate ()
        {
            //code to update UI
        });

Still incorrect, as it gave me this error:

Cannot convert anonymous method to type 'System.Delegate' because it is not a delegate type

A quick google revealed that Control.Invoke and Control.BeginInvoke take a System.Delegate as parameter that is not a delegate type and we need to cast our lambas or anonymous delegates to MethodInvoker or Action like this:

    this.BeginInvoke( (Action) (()=>
        {
            this.txtLongestWord.Text = this.longestWord;
        }));

The above code does not look good due to lot of brackets, so let’s use the anonymous delegate syntax:

    this.BeginInvoke( (Action) delegate ()
        {
            //code to update UI
        });

//or

    this.BeginInvoke( (MethodInvoker) delegate ()
        {
            //code to update UI
        });

I went to a surplus shop, and picked up the following:
4x 225W 50ohm resistors
5v 200A regulated power supply
18AWG wire
The resistors are current limiting (all in parallel) for the charger, just under 1kW. The PSU may be used in the future for augmentation, and the wire was used to make a cable.

O telescópio SUNRISE, cuja construção foi liderada pelo Instituto Max Planck para Pesquisa do Sistema Solar, na Alemanha, registrou imagens da superfície do Sol em uma resolução inédita. Movimentadas por campos magnéticos, porções de gás sobem e descem e nuvens de matéria são ejetadas, dando à superfície solar sua estrutura granulada.

Aí vão as imagens:

Cada imagem mostra a mesma região solar em quatro comprimentos diferentes de onda, como está indicado na lambda acima de cada foto. A escala é de 1 - 20000.

O telescópio que pesa mais de 6 toneladas, foi lançado de uma base na Suécia em 8 de junho e levado por um balão de hélio de 130 metros de diâmetro a uma altitude de 37 quilômetros. De lá, na estratosfera, as condições de observação são similares às do espaço: as imagens não são prejudicadas por turbulência (está acima do nível das nuvens, e o ar é muito rarefeito) e a câmera pode dar zoom em luz ultravioleta, que de outro modo seria absorvida pela camada de ozônio. As variações na radiação solar são particularmente pronunciadas em luz ultravioleta.

Separado do balão, o SUNRISE desceu de paraquedas em 14 de junho, pousando na Ilha Somerset, em território canadense. (imagina você está passeando com seu cachorro e vê um telescópio de 6t descendo de para quedas?)

Toda a informação (material de análise) colhido pelo telescópio somava cerca de 1,8 terabytes. Com base em todas essas informações (e muitas outras que ainda podem ser colhidas) está se iniciando uma intensa pesquisa sobre a atividade solar, visando descobrir muitos mistérios (inclusive aquela história que as manchas solares podem sumir em menos de 20 anos).

What’s up with no edit & continue support for methods with Lambda Expressions(mostly from LINQ queries).

Error    7    Modifying a ‘method’ which contains a lambda expression will prevent the debug session from continuing while Edit and Continue is enabled.

Originally this post was going to be “LINQ Vs. Edit and Continue”, but then I found this article on MSDN saying how it works just fine in Visual Basic.  Visual Basic!  WTF!!!

The details for VB are a little cagey though:

You can add or remove code before the LINQ statement…. Your Visual Basic debugging experience for non-LINQ code remains the same as it was before LINQ was introduced.

Does this mean if you add or remove code after a LINQ statement it stops edit and continue, or does this mean MSDN needs a better editorial staff?  The “before” seems to cast doubt on the statement that “debugging experience for non-LINQ code remains the same “  Not that I really care since I like my languages with curly brackets.

If you want to know what you can’t do in C# edit and continue, read this article.  I personally have no interest in what I can’t do. I only want to know when I’ll be able to do it and I couldn’t find any articles on that.  I heard from a friend that its not fixed in C# 4.0.  

LINQ is too good to give up, but this is really getting annoying.

I’m almost (getting this close) ready to make my own solution, or horrors, switching to VB.

Brian Schroeder, Ivy League grad accused of setting fire to a sacred 9/11 chapel, loses job offer
BY Katie Nelson
DAILY NEWS WRITER
Originally Published:Monday, November 2nd 2009, 1:55 PM
Updated: Monday, November 2nd 2009, 2:07 PM

An Ivy League law grad told his mom he must have been out of his mind to spark a blaze at a sacred 9/11 chapel – and now he’s out of a job, too.

White-shoe firm Sidley Austin yanked Brian Schroeder’s employment offer Monday morning, firm partner Bill Conlon said.

Schroeder, a Harvard Law School grad, worked in the firm’s New York office for part of the summer, Conlon confirmed.

He was supposed to return but lost the opportunity after cops say he set fire to a Manhattan chapel containing the remains of 9/11 victims in a drunken prank early Friday.

New York Daily News-Brian Schroeder, Ivy League grad accused of setting fire to a sacred 9/11 chapel, loses job offer

What kind of sickfuck is this person????????? Setting fire to a sacred place and of all things, 9/11. His defenders are just as bad. I couldn’t help noticing these in the article:

“I know him as someone who has traveled extensively and taken time to see parts of the world that many of the rest of us ignore,” said Patrick Kelly, a board member of HLS Lambda, an LGBT law-student group where Schroeder was co-president.

Alice Schroeder also defended her son as an ace student who wants to fight for human rights.

Sounds like a raving moonbat to me. Anyways, he lost his job. Too fucking bad for him. Cry me a river. Schroeder should be disbarred.

As part of my continued pursuit of the Lambda Lecture Series (my name for it) on Channel 9, I’ve summoned up a brain-storm worth of examples that show the symmetry and dualism of some functions and types. I’m not yet familiar with the higher-level abstract concepts of Arrows so arrow here simply means function.

References
– Types – Arrows – Duals [SkyDrive]

Esta semana fizemos mais uma grande melhoria na nossa camada de domínio, incorporando expressões lambda .Net nas nossas consultas e parâmetros de ordenação de repositórios. Retomando o post sobre a camada de domínio, os repositórios são utilizados para tirar a dependência da aplicação dos detalhes de persistência de objetos e para ser uma representação abstrata de uma coleção de entidades de domínio.

A idéia é que eles facilitem a busca de entidades específicas ou implementem métodos mais complexos para a execução de consultas. Como no nosso caso usamos o NHibernate para camada de persistência, nós temos duas opções de efetuar estas consultas, os Criterias (DetachedCriteria ou expressões ICriterion simples) ou o HQL, que é uma linguagem de consulta parecida com SQL só que composta pelas entidades de domínio.

Consultas HQL são baseadas em strings (ver exemplo abaixo do nosso sistema de ServiceDesk), o que é extremamente flexível porém não suporta intellisense nem é compilada (o que pode facilitar erros no caso de refactors). Mas, para o HQL não temos muita opção, a alternativa que seria usar o NH Linq ainda não é viável (pelo que eu tenho visto, ainda não suporta muitas coisas).

public int TotalInbox(User user) {
   const string hql =
       @"select count(*) from Incident i inner join i.Allocation a

         inner join a.SupportGroup s inner join s.Users u 

         inner join i.Company c
         where i.ClosedOn is null and a.SupportUser is null
         and i.State != isnull(c.WaitingUserConfirmationState,-1) 

         and i.State != isnull(c.WaitingUserInformationState, -1) 

         and u = ?";
   return (int) ExecuteScalar<long>(hql, user);
}

O uso de Criterias é mais simples e é indicado para consultas com restrições diretas na entidade base (ou nas que possuem relacionamento direto com a entidade base). Porém, nos criterias é necessário especificar o nome da propriedade como string. Novamente, sem intellisense e sujeito a problemas de refactor. Como o uso de Criterias é muito mais freqüente, nós automatizamos na nossa camada de domínio a geração de uma classe estática com todas as propriedades das entidades de domínio (usando arquivos .tt de um editor T4). Desta forma, temos intellisense e no caso de refactor que cause alguma quebra, teremos um erro de compilação (já que as classes são sempre regeradas). E, conforme falado no post da camada de domínio, construímos ainda uma fluent interface para facilitar a escrita. O exemplo abaixo mostra isto em funcionamento.

public long TotalClosed(User user) {
    return Query.Where(Restrictions.Eq(PN.User, user))

           .And(Restrictions.IsNotNull(PN.ClosedOn)).Count();
}

Esta solução estava bastante adequada até aparecer a alternativa de usarmos expressões lambda ao invés de gerar as classes estáticas. Existem algumas iniciativas já fazendo isto, como o projeto NHLambdaExtensions. Neste caso específico, porém, eles estão abordando isto como uma biblioteca à parte para a geração de Criterias do NH e não como algo integrado aos repositórios.

Felizmente, na nossa camada de domíno, os repositórios já são tipados para a entidade de domínio que eles representam. Desta foram, fica simples gerar as expressões. O exemplo abaixo mostra a mesma rotina acima, agora usando expressões lamdas.

public long TotalClosed(User user) {
    return 

      Query.Where(i => i.User == user && i.ClosedOn != null).Count();
}

Como pode ser visto, bem mais legível e intuitivo. E sem a necessidade de se usar classes estáticas de apoio! Ainda temos algum trabalho a ser feito, pois não é simples traduzir todos os tipos de lambda para restrições válidas. Mas para os casos mais simples como o acima, está já 100% funcionando.

Outro ponto interessante é que as funções que aceitam lambda podem ser expostos para camadas superiores de domínio, já que usar uma expressão lambda não causa dependência para a camada de persistência. Isto diminui de maneira significativa o próprio tamanho da implementação dos repositórios.

Finalmente, a utilização deste tipo de solução acaba sendo algo tão flexível que estamos passando a adotar em vários outros cenários. Na definição de classes de ordenação para consultas, na identificação de campos usados como atributos em formulários e controllers e assim por diante. Realmente algo muito simples que está aí desde o lançamento da versão 3.5 do .Net mas que demorou para  a “ficha cair” achar uma maneira legal de aplicar na nossa infraestrutura.

Quem quiser saber algum detalhe mais técnico da implementação basta me mandar um email. Até a próxima.

Delegates are objects that refer to methods. They are sometimes described as type-safe function pointers because they are similar to function pointers used in other programming languages. But unlike function pointers, Visual Basic delegates are a reference type based on the class System..::.Delegate.

Delegates and the AddressOf Operator.

use delegates for other, non-event related tasks, such as

• free threading or
  
• with procedures that need to call different versions of functions at run time.

Module Module1

    Sub Main()
        ' Create an instance of InOrderClass and assign values to the properties.
        ' InOrderClass method ShowInOrder displays the numbers in ascending 
        ' or descending order, depending on the comparison method you specify.
        Dim inOrder As New InOrderClass
        inOrder.Num1 = 5
        inOrder.Num2 = 4

        ' Use AddressOf to send a reference to the comparison function you want
        ' to use.
        inOrder.ShowInOrder(AddressOf GreaterThan)
        inOrder.ShowInOrder(AddressOf LessThan)

        ' Use lambda expressions to do the same thing.
        inOrder.ShowInOrder(Function(m, n) m > n)
        inOrder.ShowInOrder(Function(m, n) m < n)
    End Sub

    Function GreaterThan(ByVal num1 As Integer, ByVal num2 As Integer) As Boolean
        Return num1 > num2
    End Function

    Function LessThan(ByVal num1 As Integer, ByVal num2 As Integer) As Boolean
        Return num1 < num2
    End Function

    Class InOrderClass
        ' Define the delegate function for the comparisons.
        Delegate Function CompareNumbers(ByVal num1 As Integer, ByVal num2 As Integer) As Boolean
        ' Display properties in ascending or descending order.
        Sub ShowInOrder(ByVal compare As CompareNumbers)
            If compare(_num1, _num2) Then
                Console.WriteLine(_num1 & "  " & _num2)
            Else
                Console.WriteLine(_num2 & "  " & _num1)
            End If
        End Sub

        Private _num1 As Integer
        Property Num1() As Integer
            Get
                Return _num1
            End Get
            Set(ByVal value As Integer)
                _num1 = value
            End Set
        End Property

        Private _num2 As Integer
        Property Num2() As Integer
            Get
                Return _num2
            End Get
            Set(ByVal value As Integer)
                _num2 = value
            End Set
        End Property
    End Class
End Module

Create the delegate and matching procedures

Create the delegate and matching procedures

' Definition of function delegate ExampleDel.
Delegate Function ExampleDel(ByVal arg1 As Integer, _
                             ByVal arg2 As String) As Integer

' Declaration of del as an instance of ExampleDel, with no data 
' type specified for the parameters, m and s.
Dim del As ExampleDel = Function(m, s) m

' Valid call to del, sending in an integer and a string.
Console.WriteLine(del(7, "up"))

' Neither of these calls is valid. Function del requires an integer
' argument and a string argument.
' Not valid.
' Console.WriteLine(del(7, 3))
' Console.WriteLine(del("abc"))

There is a new lecture series on Channel 9 by Dr. Erik Meijer. It is about functional programming and is using Haskell as the the means of expression although the exact language is not so important; but Haskell is appropriate in that it is pure, lazy and has a discrete syntax.

There was a couple of questions about the execution of the programs in the beginning of the series and so for weekend fun I prepared a small document that shows two different (actually not so different) REPL’s. These may be used to execute Haskell expressions directly.

References

• Lecture Series [channel 9]
• Lecture Reference [SkyDrive]

TDK-Lambda Launches RFE1000 Power Supplies

TDK-Lambda has introduced 1kW embedded 1U-high single-output AC-DC power supplies for standalone and distributed power architecture applications requiring 24V, 32V and 48V bulk power. Up to 20 per cent output voltage adjustment is possible, enabling the RFE1000 series to be used in a variety of customer-specific applications, including battery charging.

Operating from a universal input of 85VAC to 265VAC, typical applications for the RFE1000 supplies include communications, factory automation and radio-frequency amplifiers. Efficiency of up to 89 per cent minimises heat dissipation. The RFE1000-24 ,-32 and -48 power supplies can be used individually or up to eight units can be connected in parallel to form an N+1 redundant power system with optional OR’ing diodes.

Each power supply has variable-speed cooling fans and can operate in temperatures ranging from 0C to +70C. The RFE has a power density of 10.5W/in3 with dimensions of 305 x 127 x 41mm. AC input is via a terminal block and DC output is via M5 studs. Auxiliary outputs are via a JST-type 12-way connector. Over-voltage, over-current and over-temperature protection are standard features and, for system monitoring, there are opto-isolated signals for DC OK, AC fail and over-temperature warning with a rear-panel light-emitting-diode (LED) indicator for DC OK.

Remote on/off control and remote sense features also come as standard. Other standard features include single-wire current sharing and an auxiliary 12V 0.25A output with a built-in OR’ing diode. As well as being EN55022 and FCC compliant (achieving Class B conducted and radiated emission), the RFE1000 series meets UL/EN 60950-1 safety approvals and carries the CE mark. Harmonic correction meets the EN61000-3-2 standard and the power supplies are backed by a two-year warranty.

Chapter: Sigma Phi

Colors: Sky Blue and Kelly Green

Jewels: Diamond, Saphire and Pearl

Symbols: Butterfly, Conch, Sword, and Grasshopper

Flower: Gerber Daisy

Name: Kyra Halloway

Home Town: Bayville, ND

Major: English Education

Sorority: Beta Delta

School: Midwestern University

I find myself with some more free time today so I’ll forge ahead with this challenge!

The first thing I’m going to do here is add functionality to the options and arguments and make sure they are being read in correctly. Here is my resulting code:

http://charpcfn.pastebin.com/f454f0012

Now that those are all set I can start working on file I/O. I have no idea how Ruby handles this, but it’s probably pretty easy. Time for more google!

As I expected File I/O is pretty easy. infile is going to be read in line by line and then as the times are updated each line will be written to the outfile. I’m thinking about making a class SubtitleTime and have that handle the conversion from HH:MM:SS,mmm to an object, but I’m gonna sit on that idea for a while before implementing it.

I’m spending a lot of my time looking up specific syntax here. I made sure the ternary operator was normal as well as looking up lambdas which, apparently, you have to do function.call in order for it to work…That one was a stumper. I also really like how Ruby does regular expressions. My first introduction to REs were in Perl so this is a great throwback seeing the =~ operator again.

Anyway, I’m finished programming for now, here is the code I ended up with:

http://charpcfn.pastebin.com/f1e1b9214

Overall I spent more time looking up syntax than I did library function calls but am definitely learning a lot about the Ruby language.