Coteline

Coteline 是一个全新的基于 JVM 的编程语言。Coteline 是 Ceylon 的超集，并保持对 Ceylon 的向后兼容。

比 Ceylon 改进的地方包括：

• "public as a service", because shared is not a good keyword.

• implements, because it is fancier than satisfies and it          closes the gap for existing J2EE 1.3 developers.

• Call an object a singleton.

• Use const in lieu of value.

• Write def as a Hipster-compliant variant of function.

• Ink Unit instead of void in your fine-crafted Coteline           definitions.

• contract and trait carry more meaning than          interface (and who cares about the actual formal semantics of these?).

• We think pray is a better replacement for assert, because          this is what you actually do when you write assertions.

• dynamic blocks are better named as unsafe blocks, because they          escape the wonderland of static type checks.

• Parametric types with in / out for contravariance and covariance are hard          to manipulate. This is also way too reminiscent of the C# world. Coteline          provides salvation with covar and contravar.

• Last but not least, you can also write foreach loops in Coteline.

示例代码：

"The classic Hello World program"
public Unit hello(String name = "World") {
    const str = "Hello, `` name ``!";
    def work() => print(str);
    work();
    pray(1 == 1);
    plop.plop();
    foreach (i in {1, 2, 3}) {
        print(i);
    }
}

singleton plop {
    public Unit plop() {
        print("Oh Plop!");
    }
}

"Run the module `better.ceylon.is.coteline`."
public Unit run(){
    if (nonempty args=process.arguments) {
        foreach (arg in args) {
            hello(arg);
        }
    }
    else {
        hello();
    }
}