ceylonwebide

//$webrun_wrapped
shared void run() {
"You can define a dynamic interface, so you can use
 conformant instances outside of dynamic blocks"
dynamic DataHolder {
  "This interface defines a dynamic member,
   which can only be used inside dynamic blocks"
  shared formal dynamic data;
}

ceylonwebide

//$webrun_wrapped
shared void run() {
// Using JavaScript's XMLHttpRequest to connect
// to a simple web service that returns the time
// on the server and displays it in the console
dynamic {
  print("Sending request...");
  dynamic req = XMLHttpRequest();      
  req.onreadystatechange = void() {
    if (req.readyState==4) {

ceylonwebide

//$webrun_wrapped
shared void run() {
// The JVM backend of the Ceylon compiler provides good
// interoperability with Java, so that programs can use the JDK.
// Interoperability with JavaScript is also provided, mainly
// through "dynamic" blocks. Compile-time checks are relaxed in
// these blocks (of course this can result in erros at runtime).
dynamic {
    dynamic doc = window.parent.document;
    dynamic nodes = doc.getElementsByTagName("A");

ceylonwebide

// Interfaces and abstract classes can specify a list of
// implementing types.
abstract class Node() of Leaf | Branch {}
class Leaf(item) extends Node() {
    shared Float item;
}
class Branch(left, right) extends Node() {
    shared Node left;
    shared Node right;
}

ceylonwebide

//$webrun_wrapped
shared void run() {
// Ceylon allows generic types and functions, i.e. they may have
// type parameters:
class Generic<Item>(item) {
    shared variable Item item;
    shared Item f(Item other) => other;
}
Item genericFunc<Item>(Item i) => i;

ceylonwebide

//$webrun_wrapped
shared void run() {
void order(String product, Integer count=1, Float discount=0.0,
          {String*} comments={}) {
    String commentStr = ", ".join { for (c in comments) "'``c``'" };
    print("Order '``product``', quantity ``count``, discount ``
            discount``, comments: ``commentStr``");
}

// Ceylon has an alternative syntax for invoking functions or

ceylonwebide

//$webrun_wrapped
shared void run() {
// A constant, read-only sequence of values:
String[] animals = [ "elephant", "parrot", "giraffe" ];
String[] none = []; // empty sequence

// Accessing the sequence returns an optional value (String?)
print("First: ``animals.first else "none"``");
print("Second: ``animals[1] else "none"``");
print("Fourth: ``animals[3] else "none"``");

ceylonwebide

//$webrun_wrapped
shared void run() {
// We can use a reference to a function as a value:
Float average(Float x, Float y) => (x + y) * 0.5;
value f1 = average;
print("f1(1.0, 7.0) = ``f1(1.0, 7.0)``");

// The type of f1 is Float(Float, Float):
Float(Float, Float) f2 = f1;

ceylonwebide

//$webrun_wrapped
shared void run() {
"This interface represents a customer of the shop."
interface Customer {
 
    "The name of the customer."
    shared formal String name;
 
    // Interfaces may define concrete implementations of methods
    // and getters/setters.

ceylonwebide

//$webrun_wrapped
shared void run() {
// Functions use the familiar C/Java syntax:
Float mean(Float x, Float y) {
    return ((x*x + y*y) / 2) ^ 0.5;
}
print("mean(11.0, 307.0) = ``mean(11.0, 307.0)``");

// Short form for functions consisting of a single expression
Float mean2(Float x, Float y) => ((x*x + y*y) / 2) ^ 0.5;