nicktelford

<?php
interface Comparable
{
  public function compare(self $obj);
}

class A implements Comparable
{
  public function compare(self $obj) {
    return $this == $obj;

nicktelford

$ free -m
             total       used       free     shared    buffers     cached
Mem:          3017       2953         64          0        381        671
-/+ buffers/cache:       1899       1118
                                      ^
Available memory (in MB) -------------|

The Linux kernel will allocate as much free memory as possible to buffers and caches (e.g. the fs cache)
to improve performance. When an application allocates more memory than is "free", the kernel will allocate
memory from it's caches.

nicktelford

log4j:ERROR setFile(null,true) call failed.
java.io.FileNotFoundException: /usr/lib/hadoop-0.20/logs (Is a directory)
	at java.io.FileOutputStream.openAppend(Native Method)
	at java.io.FileOutputStream.<init>(FileOutputStream.java:177)
	at java.io.FileOutputStream.<init>(FileOutputStream.java:102)
	at org.apache.log4j.FileAppender.setFile(FileAppender.java:290)
	at org.apache.log4j.FileAppender.activateOptions(FileAppender.java:164)
	at org.apache.log4j.DailyRollingFileAppender.activateOptions(DailyRollingFileAppender.java:216)
	at org.apache.log4j.config.PropertySetter.activate(PropertySetter.java:257)
	at org.apache.log4j.config.PropertySetter.setProperties(PropertySetter.java:133)

nicktelford

test_connect:
    if (connect(ptr->fd,
                (struct sockaddr *)&servAddr,
                sizeof(servAddr)) < 0)
    {
      switch (errno)
      {
      case EINPROGRESS:
      case EALREADY:
      case EINTR:

nicktelford

 INFO [NonPeriodicTasks:1] 2011-05-17 20:47:44,725 SSTable.java (line 147) Deleted /var/lib/cassandra/yyy-f-1201
 INFO [COMMIT-LOG-WRITER] 2011-05-17 20:56:48,233 CommitLogSegment.java (line 50) Creating new commitlog segment /var/lib/cassandra/commitlog/CommitLog-1305665808233.log
 INFO [ScheduledTasks:1] 2011-05-17 21:02:14,513 Gossiper.java (line 226) InetAddress /x.x.x.34 is now dead.
 INFO [GossipStage:1] 2011-05-17 21:02:14,786 Gossiper.java (line 607) InetAddress /x.x.x.34 is now UP
 INFO [ScheduledTasks:1] 2011-05-17 21:02:21,514 Gossiper.java (line 226) InetAddress /x.x.x.34 is now dead.
 INFO [HintedHandoff:1] 2011-05-17 21:03:13,676 HintedHandOffManager.java (line 295) Endpoint /x.x.x.34 died before hint delivery, aborting
 INFO [GossipStage:1] 2011-05-17 21:06:09,884 Gossiper.java (line 628) Node /x.x.x.34 has restarted, now UP again
 INFO [GossipStage:1] 2011-05-17 21:06:10,552 StorageService.java (line 724) Node /x.x.x.34 state jump to normal
 INFO [HintedHandoff:1] 2011-05-17 21:06:15,924 Hinte

nicktelford

// pretend this extractor is performance critical
object EvenExtractor {
  def unapply(x: Int): Option[Int] = {
    println("Testing for EVEN: " + x)
    if (x % 2 == 0) Option(x) else None
  }
}

// when you use it from a PartialFunction, it gets executed TWICE for all applicable values
Seq(1, 2, 3, 4) collect {

nicktelford

object Either {
  implicit def aToLeft[A, B](value: A): Left[A, B] = Left(value)
  implicit def bToRight[A, B](value: B): Right[A, B] = Right(value)
}

import Either._

case class User(id: Either[Long, String])

User(123L)

nicktelford

object Either {
  def apply[A, B](value: A): Left[A, B] = Left(value)
  def apply[A, B](value: B): Right[A, B] = Right(value)
}

val a: Either[Long, String] = Either(123L)
// a: Either[Long,String] = Left(123)

val b: Either[Long, String] = Either("123")
b: Either[Long,String] = Right(123)

nicktelford

object Any {
  implicit def matching[A](a: A): Matchable[A] = new Matchable(a)

  sealed class Matchable[A](o: A) {
    // "match" is a reserved word, so lets call it "matchIt" instead
    def matchIt[B](pf: PartialFunction[A, B]): B = {
      if(pf.isDefinedAt(o)) {
        pf(o)
      } else {
        throw new MatchError("...")

nicktelford

object App {

  case class Post(title: String,
                  body: String,
                  tags: List[String])
  case class Address(street: String,
                     city: String,
                     state: String,
                     zip: String,
                     tags: List[String])