archives

Factor Mixins

Mixins, a very interesting post from Slava Pestov's Factor blog.

Factor's object system allows the following operations without forcing unnecessary coupling:

* Defining new operations over existing types
* Defining existing operations over new types
* Importing existing mixin method suites into new types
* Importing new method suites into existing types
* Defining new operations in existing mixin method suites
* Defining new mixin method suites which implement existing operations

That's pretty much what I want from an object-functional language.

Perlis Languages

I was wondering what people would consider Perlis languages, i.e. languages worth knowing because they should change how you think about programming. Obviously there is a lot of overlap between languages so what I'm looking for is a minimal set of established languages (by that I mean 10 years or older) that still provides a reasonably complete overview of different approaches to programming. My first try at a list would look something like:

Ada, C, Haskell, Java, Lisp, Smalltalk, Perl

Peter Van Roy: Programming Paradigms for Dummies

Roy, Peter van (2009). Programming Paradigms for Dummies: What Every Programmer Should Know. In G. Assayag and A. Gerzso (eds.) New Computational Paradigms for Computer Music, IRCAM/Delatour, France.

This chapter gives an introduction to all the main programming paradigms, their underlying concepts, and the relationships between them. We give a broad view to help programmers choose the right concepts they need to solve the problems at hand. We give a taxonomy of almost 30 useful programming paradigms and how they are related. Most of them differ only in one or a few concepts, but this can make a world of difference in programming. We explain briefly how programming paradigms influence language design, and we show two sweet spots: dual-paradigm languages and a definitive language. We introduce the main concepts of programming languages: records, closures, independence (concurrency), and named state. We explain the main principles of data abstraction and how it lets us organize large programs. Finally, we conclude by focusing on concurrency, which is widely considered the hardest concept to program with. We present four little-known but important paradigms that greatly simplify concurrent programming with respect to mainstream languages: declarative concurrency (both eager and lazy), functional reactive programming, discrete synchronous programming, and constraint programming. These paradigms have no race conditions and can be used in cases where no other paradigm works. We explain why for multi-core processors and we give several examples from computer music, which often uses these paradigms.

I have not found this paper in the LTU archives, but I though it is likely of interest to this community. Of course, the author is well know here (e.g., his book Concepts, Techniques, and Models of Computer Programming). I like the bird's eye view of this paper.

Implementation of reducers and other Cilk++ hyperobjects: Peeking Under the Hood

Here's the paper submitted to the 2009 Symposium on Parallelism in Algorithms and Architectures:

Reducers and Other Cilk++ Hyperobjects