Scala has experimental support for SAMs starting with 2.11, under the flag -Xexperimental: Welcome to Scala version 2.11.0-RC3 (OpenJDK 64-Bit Server VM, Java 1.7.0_51). Type in expressions to have them evaluated. Type :help for more information. scala> :set -Xexperimental scala> val r: Runnable = () => println(“hello world”) r: Runnable = $anonfun$1@7861ff33 scala> new Thread(r).run … Read more
It is rather subjective to say whether there are “advantages” to each method. However, a good understanding of what goes under the hood would make it natural for one to pick the best choice for each occasion. A decorator (talking about function decorators), is simply a callable object that takes a function as its input … Read more
In JavaScript, statements return values of the Completion type (which is not a language type, but a specification type). The Completion type is used to explain the behaviour of statements (break, continue, return and throw) that perform nonlocal transfers of control. Values of the Completion type are triples of the form (type, value, target), where … Read more
Basics: a b is equivalent to a.b. a b c is equivalent to a.b(c), except when b ends in :. In that case, a b c is equivalent to c.b(a). a(b) is equivalent to a.apply(b) This is why the following definitions for an anonymous functions are identical: val square1 = (x: Int) => x*x val … Read more
Because you’re passing the result of the indexer, which is really the result of a method call. There’s no guarantee that the indexer property also has a setter, and passing it by ref would lead to a false security on the developer’s part when he thinks that his property is going to be set without … Read more
Generally, the : notation is used for type ascription, forcing the compiler to see a value as some particular type. This is not quite the same as casting. val b = 1 : Byte val f = 1 : Float val d = 1 : Double In this case, you’re ascribing the special varargs type. … Read more
I don’t think there’s anything deeper going on than what you have originally said: it’s just syntactic sugar whereby the compiler converts f(a) into f.apply(a) as a special syntax case. This might seem like a specific rule, but only a few of these (for example, with update) allows for DSL-like constructs and libraries.
Microsoft proposes Rolsyn API as an implementation of C# compiler with public API. It contains individual APIs for each of compiler pipeline stages: syntax analysis, symbol creation, binding, MSIL emission. You can provide your own implementation of syntax parser or extend existing one in order to get C# compiler w/ any features you would like. … Read more
As I already said in the other topic, scalac -print prints out scala code, not java. It translates all scala keywords that are not directly compatible with java to normal scala code. It is not possible to let the compiler translate only parts afaik. But basically a for-comprehension is always translated the same way. A … Read more
No. The best you can do, when the expression is overly long, is to assign it to a local variable with a short name, and use {…} to create a scope: { TypeOfFoo it = foo; // foo could be any lengthy expression it.bar(); it.reset(true); myvar = it.getName(); }