New samples from kotlin-web-site

src/test/resources/test-compile-data/jvm/kotlin-web-site/basic-syntax/5ec261721162729866abc1e8f7293ef4.31.kt

@@ -0,0 +1,20 @@
+//sampleStart
+fun getStringLength(obj: Any): Int? {
+    if (obj is String) {
+        // `obj` is automatically cast to `String` in this branch
+        return obj.length
+    }
+
+    // `obj` is still of type `Any` outside of the type-checked branch
+    return null
+}
+//sampleEnd
+
+fun main() {
+    fun printLength(obj: Any) {
+        println("Getting the length of '$obj'. Result: ${getStringLength(obj) ?: "Error: The object is not a string"} ")
+    }
+    printLength("Incomprehensibilities")
+    printLength(1000)
+    printLength(listOf(Any()))
+}

src/test/resources/test-compile-data/jvm/kotlin-web-site/basic-syntax/5ec261721162729866abc1e8f7293ef4.33.kt

@@ -0,0 +1,19 @@
+//sampleStart
+fun getStringLength(obj: Any): Int? {
+    // `obj` is automatically cast to `String` on the right-hand side of `&&`
+    if (obj is String && obj.length >= 0) {
+        return obj.length
+    }
+
+    return null
+}
+//sampleEnd
+
+fun main() {
+    fun printLength(obj: Any) {
+        println("Getting the length of '$obj'. Result: ${getStringLength(obj) ?: "Error: The object is not a string"} ")
+    }
+    printLength("Incomprehensibilities")
+    printLength("")
+    printLength(1000)
+}

src/test/resources/test-compile-data/jvm/kotlin-web-site/extensions/433cd94fef7d8fc09ee6e9ca8379b874.1.kt

@@ -1,15 +1,14 @@
-fun main() {
+fun main() { 
 //sampleStart
-    open class Shape
-    class Rectangle: Shape()
-
-    fun Shape.getName() = "Shape"
-    fun Rectangle.getName() = "Rectangle"
-
-    fun printClassName(s: Shape) {
-        println(s.getName())
-    }
-
-    printClassName(Rectangle())
-//sampleEnd
-}
+    // builder is an instance of StringBuilder
+    val builder = StringBuilder()
+        // Calls .appendLine() extension function on builder
+        .appendLine("Hello")
+        .appendLine()
+        .appendLine("World")
+    println(builder.toString())
+    // Hello
+    //
+    // World
+}
+//sampleEnd

src/test/resources/test-compile-data/jvm/kotlin-web-site/extensions/433cd94fef7d8fc09ee6e9ca8379b874.10.kt

@@ -0,0 +1,10 @@
+fun main() {
+    //sampleStart
+    data class Order(val weight: Double)
+    val calculateShipping = fun Order.(rate: Double): Double = this.weight * rate
+
+    val order = Order(2.5)
+    val cost = order.calculateShipping(3.0)
+    println("Shipping cost: $cost") 
+    // Shipping cost: 7.5
+}

src/test/resources/test-compile-data/jvm/kotlin-web-site/extensions/433cd94fef7d8fc09ee6e9ca8379b874.11.kt

@@ -0,0 +1,8 @@
+fun main() {
+    val isInRange: Int.(min: Int, max: Int) -> Boolean = { min, max -> this in min..max }
+
+    println(5.isInRange(1, 10))
+    // true
+    println(20.isInRange(1, 10))
+    // false
+}

src/test/resources/test-compile-data/jvm/kotlin-web-site/extensions/433cd94fef7d8fc09ee6e9ca8379b874.12.kt

@@ -0,0 +1,12 @@
+data class User(val firstName: String, val lastName: String)
+
+// An extension property to get a username-style email handle
+val User.emailUsername: String
+    get() = "${firstName.lowercase()}.${lastName.lowercase()}"
+
+fun main() {
+    val user = User("Mickey", "Mouse")
+    // Calls extension property
+    println("Generated email username: ${user.emailUsername}")
+    // Generated email username: mickey.mouse
+}

src/test/resources/test-compile-data/jvm/kotlin-web-site/extensions/433cd94fef7d8fc09ee6e9ca8379b874.13.kt

@@ -0,0 +1,29 @@
+data class House(val streetName: String)
+
+// Doesn't compile because there is no getter and setter
+// var House.number = 1
+// Error: Initializers are not allowed for extension properties
+
+// Compiles successfully
+val houseNumbers = mutableMapOf<House, Int>()
+var House.number: Int
+    get() = houseNumbers[this] ?: 1
+    set(value) {
+        println("Setting house number for ${this.streetName} to $value")
+        houseNumbers[this] = value
+    }
+
+fun main() {
+    val house = House("Maple Street")
+
+    // Shows the default
+    println("Default number: ${house.number} ${house.streetName}") 
+    // Default number: 1 Maple Street
+
+    house.number = 99
+    // Setting house number for Maple Street to 99
+
+    // Shows the updated number
+    println("Updated number: ${house.number} ${house.streetName}") 
+    // Updated number: 99 Maple Street
+}

src/test/resources/test-compile-data/jvm/kotlin-web-site/extensions/433cd94fef7d8fc09ee6e9ca8379b874.14.kt

@@ -0,0 +1,12 @@
+class Logger {
+    companion object { }
+}
+
+fun Logger.Companion.logStartupMessage() {
+    println("Application started.")
+}
+
+fun main() {
+    Logger.logStartupMessage()
+    // Application started.
+}

src/test/resources/test-compile-data/jvm/kotlin-web-site/extensions/433cd94fef7d8fc09ee6e9ca8379b874.15.kt

@@ -0,0 +1,32 @@
+class Host(val hostname: String) {
+    fun printHostname() { print(hostname) }
+}
+
+class Connection(val host: Host, val port: Int) {
+    fun printPort() { print(port) }
+
+    // Host is the extension receiver
+    fun Host.printConnectionString() {
+        // Calls Host.printHostname()
+        printHostname() 
+        print(":")
+        // Calls Connection.printPort()
+        // Connection is the dispatch receiver
+        printPort()
+    }
+
+    fun connect() {
+        /*...*/
+        // Calls the extension function
+        host.printConnectionString() 
+    }
+}
+
+fun main() {
+    Connection(Host("kotl.in"), 443).connect()
+    // kotl.in:443
+
+    // Triggers an error because the extension function isn't available outside Connection
+    // Host("kotl.in").printConnectionString()
+    // Unresolved reference 'printConnectionString'.
+}

src/test/resources/test-compile-data/jvm/kotlin-web-site/extensions/433cd94fef7d8fc09ee6e9ca8379b874.16.kt

@@ -0,0 +1,48 @@
+open class User
+
+class Admin : User()
+
+open class NotificationSender {
+    open fun User.sendNotification() {
+        println("Sending user notification from normal sender")
+    }
+
+    open fun Admin.sendNotification() {
+        println("Sending admin notification from normal sender")
+    }
+
+    fun notify(user: User) {
+        user.sendNotification()
+    }
+}
+
+class SpecialNotificationSender : NotificationSender() {
+    override fun User.sendNotification() {
+        println("Sending user notification from special sender")
+    }
+
+    override fun Admin.sendNotification() {
+        println("Sending admin notification from special sender")
+    }
+}
+
+fun main() {
+    // Dispatch receiver is NotificationSender
+    // Extension receiver is User
+    // Resolves to User.sendNotification() in NotificationSender
+    NotificationSender().notify(User())
+    // Sending user notification from normal sender
+
+    // Dispatch receiver is SpecialNotificationSender
+    // Extension receiver is User
+    // Resolves to User.sendNotification() in SpecialNotificationSender
+    SpecialNotificationSender().notify(User())
+    // Sending user notification from special sender 
+
+    // Dispatch receiver is SpecialNotificationSender
+    // Extension receiver is User NOT Admin
+    // The notify() function declares user as type User
+    // Statically resolves to User.sendNotification() in SpecialNotificationSender
+    SpecialNotificationSender().notify(Admin())
+    // Sending user notification from special sender 
+}