In Relation To

Today Oracle's Mark Reinhold published the requirements for comment a public draft of the Java Module system being proposed for inclusion into the Java SE 8 platform. The requirements as given are fairly high-level yet comprehensive, and many of these requirements align well with the goals and specifications of our own JBoss Modules system, which is not only a strong validation of our own design but also what I think is a good sign for the future of the Java platform.

Ceylon is a language for defining structured data as well as regular procedural code. One of the first things you run into when defining data formats is the need for micro-languages - syntactic validation for character strings that represent literal values of some data type. For example:

One of the best features of Ceylon is lexically-scoped introduction, which we discussed here, calling it decoration.

We've already discussed the theory behind operators in Ceylon, but I missed out on giving you guys an actual list of them. In compiling this list of operators, we've tried to select operators that make code easier to read instead of harder to read. (Ceylon is supposed to be a language that eschews ASCII-art.) There are a couple of operators in the list that I have doubts about, especially the format operator, $, that is used to format an object to a string.

This is the final installment in a series of articles introducing the Ceylon language. Note that some features of the language may change before the final release.

I'm speaking about Ceylon on Thursday, June 23, at 10am at JAX in San Jose. My last conference presentation on the subject of Ceylon was well-received at the conference itself, but not when subsequently published online, leaving we with the impression that it wasn't very effective. So I'm taking a different tack this time.

In Introduction to Ceylon Part 8 we discussed Ceylon's support for defining higher order functions, in particular the two different ways to represent the type of a parameter which accepts a reference to a function. The following declarations are essentially equivalent:

We've talked quite a lot about union types, and even seen some of their many applications, but one thing I didn't mention is that they can be used as a kind of checked exception facility. Consider the following method declaration:

In Ceylon, the following class has an initializer with two locals: