atooni

package zio.insight.webapp

import scala.scalajs.js
import scala.scalajs.js.Dynamic.literal
import scala.scalajs.js.annotation.JSGlobal

import com.raquo.laminar.api.L._
import com.raquo.laminar.builders.HtmlTag
import com.raquo.laminar.nodes.ReactiveElement

djspiewak

Getting Started in Scala

This is my attempt to give Scala newcomers a quick-and-easy rundown to the prerequisite steps they need to a) try Scala, and b) get a standard project up and running on their machine. I'm not going to talk about the language at all; there are plenty of better resources a google search away. This is just focused on the prerequisite tooling and machine setup. I will not be assuming you have any background in JVM languages. So if you're coming from Python, Ruby, JavaScript, Haskell, or anywhere…  I hope to present the information you need without assuming anything.

Disclaimer It has been over a decade since I was new to Scala, and when I was new to Scala, I was coming from a Java and Ruby background. This has probably caused me to unknowingly make some assumptions. Please feel free to call me out in comments/tweets!

One assumption I'm knowingly making is that you're on a Unix-like platform. Sorry, Windows users.

Getting the JVM

oscarcs

import org.lwjgl._
import org.lwjgl.glfw._
import org.lwjgl.opengl._

import org.lwjgl.glfw.Callbacks._
import org.lwjgl.glfw.GLFW._
import org.lwjgl.opengl.GL11._
import org.lwjgl.system.MemoryUtil._

object Main {

djspiewak

Collections Redesign Proposal

I'm going to start off by motivating what I'm doing here. And I want to be clear that I'm not "dissing" the existing collections implementation or anything as unproductively negative as that. It was a really good experiment, it was a huge step forward given what we knew back in 2.8, but now it's time to learn from that experiment and do better. This proposal uses what I believe are the lessons we can learn about what worked, what didn't work, and what is and isn't important about collections in Scala.

This is going to start out sounding really negative and pervasively dismissive, but bear with me! There's a point to all my ranting. I want to be really clear about my motivations for the proposal being the way that it is.

Problems

Generic Interfaces

brianwawok

//EXAMPLE evolution.scala


import java.io.{File, FilenameFilter}

import com.datastax.driver.core.Session
import org.apache.commons.io.filefilter.SuffixFileFilter
import org.joda.time.{DateTime, DateTimeZone}
import play.api.Play.current
import play.api.{Logger, Play}

ikenna

sbt> eval new scala.sys.SystemProperties().foreach(x => println(x)) 

sbt> eval scala.sys.env.foreach(x => println(x))

skiadas

The thing that students have the hardest time on when learning functional programming is how to process a recursive structure while maintaining some sort of "state", the result if you will. I'll attempt here to demystify the process.

Functional programming languages almost always use a lot of recursively defined structures. Depending on the language those can be implemented in various ways, but in any case the end result is the same. A structure of this type is either an "atom", i.e. an irreducible thing, or a "compound" consisting of substructures of the same form.

For example a "list" is either an Empty/Nil list (the "atom") or it is formed as a Cons of a value and another list (compound form). That other "sublist" can itself be empty or another cons and so on and so forth. A tree is similar. It is either empty, or it consists of a triple of a value and two sub-trees, left and right.

Almost every problem we encounter is a question about doing something with all entries in a structure. To solve these prob

Arneball

object MySorts extends Ordering.ExtraImplicits {

  def mergeSort[T : Ordering](elems: List[T]): List[T] = elems match {
    case Nil | _::Nil => elems
    case that =>
      type L = List[T]
      def merge(l1: L, l2: L, acc: L): L = l1 -> l2 match {
        case (a::as, b::_) if a < b => merge(as, l2, a::acc)
        case (_, b::bs) =>  merge(l1, bs, b::acc)
        case (a::as, _) =>  merge(as, l2, a::acc)

scmx

Upgrade/Install ruby 2.1.2

ubuntu 12.04 14.04

Reference http://stackoverflow.com/a/18490935/2037928

Login as root

Install needed packages

apt-get -y install build-essential zlib1g-dev libssl-dev libreadline6-dev libyaml-dev

timyates

package java8tests ;

import java.util.function.BiFunction ;
import java.util.function.Function ;

public class Currying {

    public void currying() {
        // Create a function that adds 2 integers
        BiFunction<Integer,Integer,Integer> adder = ( a, b ) -> a + b ;