alexwestphal

// Rename the import to TFConfig
import com.example.config.TraversalFailureConfiguration as TFConfig

// Can now use it anywhere in the file as if TFConfig was it's actual name

fun main(args: Array<String>) {
    val config: TFConfig = TFConfig()
}

alexwestphal

// A sealed class is a special kind of abstract class. The difference being that for a sealed class, all subclasses must
// be declared in the same file. This means that the compiler knows about the fixed set of subclasses.
sealed class Shape {
    abstract val area: Double
}

data class Circle(val radius: Double): Shape() {
    override val area = Math.PI * radius * radius
}

alexwestphal

// The buildString function simplifies the use of StringBuilder
val s = buildString {
    append("Hello")
    append(" ")
    append("World")
} 

// Is equivalent to
val stringBuilder = StringBuilder()
stringBuilder.append("Hello")

alexwestphal

// Write to a file using the `use` method to close the PrintWriter when finished or if an error occurs.
// Semantics are pretty much the same as Java's try-with-resource
File("hello.txt").printWriter().use { out -> 
  out.println("Hello World")
} 

// Which is roughly equivalent to

val file = File("hello.txt")
val outputStreamWriter = OutputStreamWriter(FileOutputStream(file), Charsets.UTF_8)

alexwestphal

// Define a data class to hold the result
data class FoundThings(val x: Int, val y: String, val z: Double)

// Your function returns an instance of the data class
fun findThings(): FoundThings {
    // Do lookups

    return FoundThings(2, "hello", 4.0)
}

alexwestphal

sealed abstract class Side
case object Left extends Side
case object Right extends Side

sealed abstract class Thing
case object Cabbage extends Thing
case object Goat extends Thing
case object Wolf extends Thing

alexwestphal

"\e[A": history-search-backward
"\e[B": history-search-forward
set show-all-if-ambiguous on
set completion-ignore-case on

alexwestphal

import java.util.Random;

public class NotRandom {

	public static void main(String[] args) {
		System.out.println(randomString(0xf24ab354)+' '+randomString(0xf72f13ef));
		//Prints "hello world"
	}

	public static String randomString(int seed) {

alexwestphal

def sort(xs: Array[Int]): Array[Int] = {
  if (xs.length <= 1) xs
  else {
    val pivot = xs(xs.length / 2)
    Array.concat(
      sort(xs filter (pivot >)),
      xs filter (pivot ==),
      sort(xs filter (pivot <)))
  }
}