Avaliando Scala

AtorCalculador.scala

case object Calcule
case object Pare

class Calculador extends Actor {
  val rand = new Random
  var pi, in, cnt = 1.0

  def act() {
    while (true) {
      receive { //aguarda uma mensagem
        case Calcule =>
          //envia uma estimativa para o coordenador
          sender ! estimativaDePi
        case Pare => exit
      }
    }
  }

  def estimativaDePi: Double = {
    val x = rand.nextDouble - 0.5
    val y = rand.nextDouble - 0.5
    cnt += 1.0;
    if (sqrt(x * x + y * y) < 0.5) in += 1
    return in / cnt * 4
  }
}

AtorCoordenador.scala

class Coordenador(qtdCalculadores: Int) extends Actor {
  def act() {
    val inicio = currentTimeMillis
    var calculadores = List.fill(qtdCalculadores)(new Calculador)
    calculadores.foreach(c => {
      c.start
      c ! Calcule
    })
    while (true) {
      receive {
        case estimativa: Double =>
          val erro = abs(Pi - estimativa)
          if (erro > 0.0000001)
            sender ! Calcule
          else {
            val tempo = currentTimeMillis - inicio
            calculadores.foreach(_ ! Pare)
            println("Pi encontrado por " + sender + " = " + estimativa)
            println("Tempo de Execução: " + tempo)
            exit
          }
      }
    }
  }
}

ComplexDeclaration.scala

def ++ [B >: A, That] (that: TraversableOnce[B])(implicit bf: CanBuildFrom[List[A], B, That]) : That

FiboFunc.scala

object FiboFunc {
  val fibs: Stream[BigInt] =
    0 #:: 1 #:: (fibs zip fibs.tail).map { case (a, b) => a + b }
  def main(args: Array[String]) = println(fibs(1000));
}

FiboJava.java

public class FiboJava {
  private static BigInteger fibo(int x){
    BigInteger a= BigInteger.ZERO;
    BigInteger b= BigInteger.ONE;
    BigInteger c= BigInteger.ZERO;
    for(int i=0; i<x; i++){
      c = a.add(b);
      a = b;
      b = c;
    }
    return a;
  }
	  
  public static void main(String args[]){
    System.out.println(fibo(1000));
  }
}

FiboScala.scala

object FiboScala {
  def fibo(x:Int):BigInt = {
    var a:BigInt = 0;
    var b:BigInt = 1;
    var c:BigInt = 0;
    for(_ <- 1 to x){			 
      c = a+b;
      a = b;
      b = c;
    }
    return a;
  }  
  
  def main(args: Array[String]) = println(fibo(1000))
}

FilaTraits1.scala

abstract class FilaInt {
  def get(): Int
  def put(x: Int)
  def size(): Int
}

class FilaIntSimples extends FilaInt {
  private val buf = new ArrayBuffer[Int];
  def get = buf.remove(0)
  def put(x: Int) { buf += x }
  def size = buf.length
}

trait Dobra extends FilaInt {
  abstract override def put(x: Int) { super.put(2 * x) }
}

trait Incrementa extends FilaInt {
  abstract override def put(x: Int) { super.put(x + 1) }
}

trait Filtra extends FilaInt {
  abstract override def put(x: Int) { if (x > 0) super.put(x) }
}

FilaTraits2.scala

//Combinando traits na definicao de tipos
class FilaDobroMaisUm extends FilaIntSimples with Incrementa with Dobra

object FilaComTrait {
  def main(args: Array[String]) {
    val fila1 = new FilaDobroMaisUm;
    fila1.put(1);
    fila1.put(2);
    println(fila1.get());
    println(fila1.get());

    //Combinando traits na instanciaçao
    val fila2 = new FilaIntSimples with Filtra
    fila2.put(-1);
    fila2.put(1);
    println(fila2.size());

  }
}

ListMacsJava.java

public class ListMACsJava {
  public static void main(String[] args) throws SocketException {
    Enumeration<NetworkInterface> nics = 
    		NetworkInterface.getNetworkInterfaces();
	for (NetworkInterface nic : Collections.list(nics)) {
      byte[] mac = nic.getHardwareAddress();
      for (int i = 0; mac != null && i < mac.length; i++) {
        System.out.format("%2x", mac[i]);
        System.out.print(i == mac.length - 1 ? '\n' : ':');
      }
    }
  }
}

ListMacsScala.scala

object ListMACsScala {
  def main(args: Array[String]) {
    NetworkInterface
      .getNetworkInterfaces
      .flatMap(nic => Option(nic.getHardwareAddress))
      .map(_ map ("%02x" format _) mkString ":")
      .foreach(println(_));
  }
}

Opa Julio! Aqui no map.flatten do LstMacsScala.scala daria para ter invocado flatMap? Abraço!

daria...

NetworkInterface
.getNetworkInterfaces
.map(nic => Option(nic.getHardwareAddress))
.flatMap(x=>x)
.map(_ map ("%02x" format ) mkString ":")
.foreach(println());

Abs!

Opa JUlio! Acho que da pra juntar ele com a linha de cima ai fica flatMAp(nic ... ) sem a linha seguinte. Literalmente o flatmap eh o map flateado. Abraco!

…

On Mar 16, 2012 9:48 AM, "Julio Faerman" < ***@***.***> wrote: daria... NetworkInterface .getNetworkInterfaces .map(nic => Option(nic.getHardwareAddress)) .flatMap(x=>x) .map(_ map ("%02x" format _) mkString ":") .foreach(println(_)); Abs! --- Reply to this email directly or view it on GitHub: https://gist.github.com/2043922

Eu tentei : .flatMap(_ map ("%02x" format _) mkString ":")
Mas java.util.IllegalFormatConversionException: x != [B (os elementos ficam diferentes )

Como seria direto com flatMap?

Opa julio Desculpa estou no cel ai sai tudo pela metade. E assim? NetworkInterface .getNetworkInterfaces .flatmap(nic => Option(nic.getHardwareAddress)) .map(_ map ("%02x" format _) mkString ":") .foreach(println(_));

…

On Mar 16, 2012 9:55 AM, "Julio Faerman" < ***@***.***> wrote: Eu tentei : .flatMap(_ map ("%02x" format _) mkString ":") Mas java.util.IllegalFormatConversionException: x != [B ( os elementos ficam diferentes ) Como seria direto com flatMap? --- Reply to this email directly or view it on GitHub: https://gist.github.com/2043922

Humm.. entendi e alterei no gist, obrigado!

Combinar funcoes eh sempre uma diversao... Eu era mais reticente. Agora so soi um pouco...

…

On Mar 16, 2012 11:53 AM, "Julio Faerman" < ***@***.***> wrote: Humm.. entendi e alterei no gist, obrigado! --- Reply to this email directly or view it on GitHub: https://gist.github.com/2043922