Lambda the Ultimate

C-omega, Microsoft Research's experimental language featuring asynchronous concurrency (formerly, Polyphonic C#) and XML data types (Xen), is now available for download.

I think this is an interesting project. It was discussed here several times in the past.

I think that the integration of the new features with the core language is quite nice (e.g., XML types and the type system), so I suggest taking a look even if you are not particularly in favor of embedding XML in programming language.

The Cw home page includes links to relevant papers. And here's a LtU discussion of Xen and a discussion of Polyphonic C#.

The ongoing LtU discussion.

This project's goal is to provide integrated support for Aspect Orientated Programming in Oracle's JDeveloper IDE. Where possible we hope to make use of, and reuse code from, projects that have solved similar problems for other IDEs. The initial focus of the project is to integrate ADJT, the AspectJ design time environment, into JDeveloper.

It would be interesting to see whether projects such as this will help get AOP accepted by industry.

This project is very interesting: a CLR-based language with Python-esque syntax, optional type declarations, open compilation pipeline, and some interesting ideas about generators and class attributes. There are some unique ideas about running a dynamic language atop the CLR, as well, like syntax to declare "duck" typing for individual objects, which lets you use them as dynamic proxies for COM objects, web services, etc.

It's definitely a bit green, but if even a significant fraction of the features discussed in the "manifesto" are there, it looks like an impressive effort, regardless.

Snowball is a small string processing language designed for creating stemming algorithms for use in Information Retrieval.

And here's a sample program.

I am not sure just how exciting this language is, but it has been a while since we discussed a DSL.

(via Val Henson's weblog)

This paper (from HotOS IX) describes a software design approach which seems very close to the design techniques erlang tries to encourage.

For all those (like me) who didn't get the memo, I just found out that the seemingly defunct ll1-discuss mailing list has in fact found a new home at:

http://lists.csail.mit.edu/pipermail/ll-discuss/

A very pleasant 1996 interview with Donald Knuth by Jack Woehr of Dr. Dobb's Journal.

Ralf Hinze. Theoretical Pearl: Church numerals, twice! Journal of Functional Programming, 2004. To appear.

This pearl explains Church numerals, twice. The first explanation links Church numerals to Peano numerals via the well-known encoding of data types in the polymorphic LC. This view suggests that Church numerals are folds in disguise. The second explanation, which is more elaborate, but also more insightful, derives Church numerals from first principles, that is, from an algebraic specification of addition and multiplication. Additionally, we illustrate the use of the parametricity theorem by proving exponentiation as reverse application correct.

A simple concept is used to demonstrate several interesting and useful techniques.

(Link)

Vadim Nasardinov pointed out this article, which although pitched at an introductory level, provides a reasonably thorough overview of functional programming possibilities in Java. It focuses on the use of closures and higher-order functions, via Java's anonymous inner classes, and works its way up to "using closures to implement business rules" as one of its concrete examples.

Perhaps a little too introductory for LtU, but articles like this can be a useful starting point when talking to Java programmers who've had little or no previous exposure to FP, or who need some hints about useful ways to apply FP concepts in Java. Using anonymous inner classes to implement e.g. GUI event listeners in Java is common practice, but often, more advanced and useful possibilities are overlooked.

Objective Caml release 3.08.0 is official and incorporates many improvements. A big thank-you to the OCaml team for this stable release. Those on the bleeding edge of post-3.08 CVS work can follow Xavier's advice.