In Relation To

I've been thinking about the problem of passing a Sequence of values to a sequenced parameter in Ceylon (a varargs parameter in Java terminology). Consider:

I've just finished implementing support for self types and type families in the Ceylon type analyzer. I think this stuff is pretty cool, if ever so slightly esoteric.

Gilad Bracha writes.

A number of people have asked if Ceylon will have tuples. Well, I suppose, why not? It's easy enough to write the following generalized algebraic datatype:

Today I came up with an awesome new way to do annotation constraints in Ceylon, essentially using the metamodel types (yes, I mean the metamodel types, not the actual metamodel type instances) as a kind of query language for program elements. The advantages of the new approach are:

A method reference like Float.times is represented in curried form in Ceylon. I can write:

I just ran across a great usecase for existential types (like Java's wildcard types, which Ceylon doesn't and won't support). It's a little involved, and revolves around an advanced feature of Ceylon that other languages don't have: the typesafe metamodel. But let me see if I can get the idea across.

Despite having spent several years designing frameworks and specifications based around the notion of dependency injection, I've never especially considered myself a big fan of the whole thing. Dependency injection strikes me as more of a fashion within one particular programming community than as some enduring pattern that will be reproduced in future languages by future framework designers.

I've updated Part 3 and Part 11 of Introduction to Ceylon to incorporate some recent revisions to the language and fill in some missing details. I've also added some extra material explaining the reasoning behind a couple of the important decisions we've made.

I can't wait to try my hand at creating a Ceylon wrapper for JavaFX 2. The Ceylon language was designed with this kind of problem in mind. And JavaFX was originally designed for a language with some of the same ideas in it as Ceylon. Damn, better get back to work on that damn compiler I keep promising...