Call Processing Language

Where the word "Call" stands for phone call, not procedure call.

Call Processing Language (CPL): A Language for User Control of Internet Telephony Services

This document defines the Call Processing Language (CPL), a language to describe and control Internet telephony services. It is designed to be implementable on either network servers or user agents. It is meant to be simple, extensible, easily edited by graphical clients, and independent of operating system or signalling protocol. It is suitable for running on a server where users may not be allowed to execute arbitrary programs, as it has no variables, loops, or ability to run external programs.
When I saw the requirement to have no loops I thought about Epigram immediately... If it only was edited easily by graphical clients ;-)

On a serious side - here is a nice example of real life requirement to be NOT Turing complete!

Generic Functions have Landed (Python)

A semi-stable generic function API for Python.

Somewhere between CLOS style OOP and AOP, I'd say.

I don't have the time to explore this, but other might wnat to give it a go and report their experience.

The Xtatic experience

Vladimir Gapeyev, Michael Y. Levin, Benjamin C. Pierce, and Alan Schmitt. The Xtatic experience. Technical Report MS-CIS-04-24, University of Pennsylvania, October 2004.

The aim of the present paper is to discuss Xtatic - less formally and more holistically - from the perspective of language design. We survey the most significant issues we faced in the design process and evaluate the choices we have made in addressing them.

As you'd expect a lot of time is spent explaining the design decisions concerning the type system.

More Xtatic papers here.

ACM Queue: There’s Still Some Life Left in Ada

Well, at least according to this article.
Much as I like Ada, I find this article a bit unbalanced, so feel free to criticize it and the language, if you like.

Haskell Communities and Activities Report, Seventh Edition, November 2004

The November 2004 edition of the biannual Haskell Communities and Activities Report has been published. Lots of new stuff in the last six months, and some old stuff updated as well. The HC&AR has been steadily growing over the last three years, showing that FP is gaining users both professional and private.

Several of the HC&AR items are interesting enough to have their own LtU stories, which may appear shortly.

The Essential Haskell Compiler

On the same subject as the Scheme compiler in 90 Minutes, is the Essential Haskell Compiler. From the HC&AR summary:

The purpose of the EHC project is to provide a description a Haskell compiler which is as understandable as possible so it can be used for education as well as research


In order to avoid overwhelming the innocent reader, the description of the compiler is organised as a series of increasingly complex steps. Each step corresponds to a Haskell subset which itself is an extension of the previous step. The first step starts with the essentials, namely typed lambda calculus.



Sounds like BC Pierce's Types and Programming Languages.
Also notable is that EHC uses Utrecht's Attribute Grammars, which are interesting in their own right.

Quick update

Due to family health problems I am away from my computer most of time, and not reading PL papers.

I'd appreciate it if the other editors take up the slack...

Predicate Dispatch in the news

Lemonodor writes about predicte dispatch in CLOS, Patrick writes about Smalltalk (and see the comments regarding Python).

A few more posts are floating around, so follow the links from these two blog posts.

Where is everyone?

Editors, are you all still tired because of the election?

I'm feeling lonely around here.

OOPSLA essays track

The program chair for OOPSLA 2005, Richard P. Gabriel, wants to shake things up. As part of that he's going to institute an Essays track, and I will be program chair for that track. I'm hunting for people to serve on the committee. -- Brian Marick

Might want to send in your suggestions.

Me, I am going to think of an essay topic...