gvolpe

Dependency Injection in Functional Programming

There exist several DI frameworks / libraries in the Scala ecosystem. But the more functional code you write the more you'll realize there's no need to use any of them.

A few of the most claimed benefits are the following:

• Dependency Injection.
• Life cycle management.
• Dependency graph rewriting.

mandubian

import scala.language.higherKinds

object Test extends App {

  // PKList or the Any-Order heterogenous list
  sealed trait PKList[Args <: AnyKind]

  trait PKNil[Args <: AnyKind] extends PKList[Args]

  sealed trait PKCons[Args <: AnyKind, HA, TA <: PKList[Args]] extends PKList[Args] {

eamelink

Recursion and Trampolines in Scala

Recursion is beautiful. As an example, let's consider this perfectly acceptable example of defining the functions even and odd in Scala, whose semantics you can guess:

def even(i: Int): Boolean = i match {
  case 0 => true
  case _ => odd(i - 1)
}

def odd(i: Int): Boolean = i match {

aguegu

# Basic Strongswan ikev2 server setup
 
* paltform: atlantic.net ubuntu 14.04 x64
* the commands below are run with root account 

## Strongswan
```
apt-get install strongswan
apt-get install iptables iptables-persistent
```

cvogt

import scala.slick.lifted.CanBeQueryCondition
// optionally filter on a column with a supplied predicate
case class MaybeFilter[X, Y](val query: scala.slick.lifted.Query[X, Y]) {
  def filter[T,R:CanBeQueryCondition](data: Option[T])(f: T => X => R) = {
    data.map(v => MaybeFilter(query.filter(f(v)))).getOrElse(this)
  }
}

// example use case
import java.sql.Date

jexchan

Multiple SSH Keys settings for different github account

create different public key

create different ssh key according the article Mac Set-Up Git

$ ssh-keygen -t rsa -C "your_email@youremail.com"