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#!/usr/bin/env bash

KOTLIN=$(find . -name "*.kt" -exec cat {} \; | wc -l)
JAVA=$(find . -name "*.java" -exec cat {} \; | wc -l)

echo Kotlin: $KOTLIN lines \($(echo scale=2\; 100 \* $KOTLIN / \( $KOTLIN + $JAVA \) | bc -l)%\)
echo Java  : $JAVA lines \($(echo scale=2\; 100 \* $JAVA / \( $KOTLIN + $JAVA \) | bc -l)%\)

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// when is an expression, not a statement!
fun symbolOf(currency: Currency) : String {
  return when(currency) {
    Currency.USD -> "$"
    Currency.EUR -> "€"
    Currency.GBP -> "£"
    Currency.BTC -> "₿"
    Currency.ETH -> "⧫"
    else -> {
      log("warning: unknown symbol")

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interface View {
  fun click()
  fun toggle()
}

class ViewImpl: View {
  override fun click()  { println("click!") }
  override fun toggle() { println("toggle!") }
}

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// until and step are infix functions
for(i in 0 until 100 step 2) println("$i")
// equivalent to:
for(i in 0.until(100).step(2)) println("$i")

// downTo is an infix function
for(i in 100 downTo 0) println("$i")

// shl, and, xor are infix functions
val i = (0x65acf9 shl 6) and 0x55 xor 0x80

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val list = listOf("Kotlin", "", "Java", "Groovy")

fun main() {  
  list.forEach {
    if(it.isNullOrEmpty()) return@forEach  // return with implicit label
    println(it)    
  }
  println("Done!")
}

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// Kotlin's standard library extension
inline fun Array<String>.forEach(action: (String) -> Unit) {
  for(str in this) {
    action(str)
  }
}

val list = listOf("Kotlin", "Java", "Groovy")

// a bare return statement in a lambda called from 

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inline fun greeter(action: () -> Unit) {
  try {
    println("Hello!")
    action()
  }finally{
    println("Goodbye!")
  }
}

greeter {

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enum class Direction { 
  NORTH, SOUTH, WEST, EAST 
}

enum class Color(val rgb: Int) {
  RED(0xFF0000),
  GREEN(0x00FF00),
  BLUE(0x0000FF)
}

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// the returned value is the last expression of the try or catch block
val a: Int? = try { parseInt(input) } catch (e: NumberFormatException) { null }

fun printNumber(reader: BufferedReader) {
  
  val number = try { 
    parseInt(reader.readLine())
  } catch (e: NumberFormatException) {
    return
  }

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val listener = object: OnMenuClickListener, OnMenuExpandListener {
  override fun onMenuClick(item: Menu)  { ... }
  override fun onMenuExpand(item: Menu) { ... }
}

menu.setOnClickListener(listener)
menu.setOnExpandListener(listener)