darekmydlarz

If you want to learn Scala, I’d suggest:

• Install IntelliJ + Scala Plugin
• Don’t do the Coursera courses yet.
• Don’t do the “red book” Functional Programming in Scala yet.
• Do: http://underscore.io/books/
  • Essential Scala
  • Essential Play
  • Essential Slick
• Do Scala for the Impatient: https://www.amazon.com/Scala-Impatient-Cay-S-Horstmann/dp/0321774094
• The Neophyte’s Guide to Scala http://danielwestheide.com/scala/neophytes.html

darekmydlarz

// vavr (aka javaslang)
public Set<Integer> usersIds() {
    return managerNode.descendants()
        .flatMap(Node::userIds);
}

// (POJ8) Plain Old Java 8
public java.util.Set<Integer> usersIds() {
    return managerNode.descendants()
        .stream()

darekmydlarz

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

---

This tutorial as a series of videos

If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.

---

darekmydlarz

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

darekmydlarz

Keybase proof

I hereby claim:

• I am dmydlarz on github.
• I am dmydlarz (https://keybase.io/dmydlarz) on keybase.
• I have a public key ASBWpjF_o-mj0hbfz92oU83e6FFunYYPIqsqjljk5sCUIwo

To claim this, I am signing this object:

darekmydlarz

void prejava8() throws MalformedUrlException {
  Map<String, Cluster> clusters = Maps.newHashMap();
  for (final Map<String, Object> clusterYml : clustersListYml) {
    Cluster cluster = new HystrixCluster(clusterAdapter.fromMap(clusterYml));
    clusters.put(cluster.name(), cluster);
  }
  return clusters;
}

void java8() {

darekmydlarz

public class Task {
    public String getAction() {...}
    public LocalDateTime getDueDate() {...}
    
    public boolean isOverdue(Clock clock) {
        return LocalDateTime.now(clock).isAfter(getDueDate());
    }
}

darekmydlarz

# jupyter notebook --generate-config
# vim .jupyter/jupyter_notebook_config.py

import os
import sys

spark_home = os.environ.get('SPARK_HOME', None)
sys.path.insert(0, spark_home + "/python")
# FIXME make sure you have got correct py4j version
sys.path.insert(0, os.path.join(spark_home, 'python/lib/py4j-0.9-src.zip'))

darekmydlarz

# install fortune
brew install fortune

# backup current fortunes
mv -r /usr/local/Cellar/fortune/9708/share/games/fortunes /usr/local/Cellar/fortune/9708/share/games/fortunes.bak

# download bash.org.pl quotes
curl -s http://bash.org.pl/text > bash_text

# create random access file

darekmydlarz

// Check whether --offline was passed to gradle and set it in the test configuration's system properties
test {

    if(gradle.startParameter.isOffline()) {
        systemProperties 'TESTS.ARE.OFFLINE' : '1'
    }

}