A Quick Language Tour

package level functions

package com.talios.kotlin

fun sayHello(name: String) {
  println("Hello " + name)
}

String interpolation

package com.talios.kotlin

fun sayHello(name: String) {
  println("Hello $name")
}

Extension Methods

package com.talios.kotlin

fun String.wrapDiv(cssClass: String = "") = "
$this
"
  
fun sayHello(name: String) = println("Hello $name".wrapDiv())

fun shoutHello(name: String) = println(
  "hello $name".wrapDiv(cssClass="loud")

Lambdas

fun lock<T>(lock : Lock, body : () -> T) : T {
  lock.lock()
  try {
    return body()
  }
  finally {
    lock.unlock();
  }
}

fun toBeSynchronized() = sharedResource.operation()

val result = lock(lock, ::toBeSynchronized)

val result = lock(lock, { sharedResource.operation() })

lock (lock) {
  sharedResource.operation()
}

INfix notation

// Define extension to Int
fun Int.shl(x: Int) {
..
}

// call extension function using infix notation

1 shl 2

// is the same as

1.shl(2)

data classes

 data class Person(first: String, last: String, age: Integer)

• Immutable
• Equals
• Hash Codes
• To String
• Copying
• Desctrucuturing

Destructuring binds

data class Person(first: String, last: String, age: Integer)

val bob = Person("Bob", "Dobalina", 37)

val (first, last, age) = bob

class Person {
  fun component1(): String =...
  fun component2(): String =...
  fun component3(): Integer =...
}