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...

eWeek: Programming Legends Debate .Net, J2EE

At a session entitled "The Great J2EE vs. Microsoft .Net Shootout" at the OOPSLA conference here this week, software development superstars debated the relative strengths and weaknesses of Microsoft's .Net and Sun's Java 2 Platform, Enterprise Edition. The panelists included Anders Hejlsberg, Microsoft Corp. distinguished engineer and lead designer for the C# language; John Crupi, chief Java architect for Sun Services at Sun Microsystems Inc.; Don Box, leading Microsoft architect on its Indigo project; Rob High, IBM's chief architect for the WebSphere Application Server Family; and Alan Knight, lead developer for the Web Toolkit at Cincom Systems Inc. and a Smalltalk expert.

From the eWeek coverage it would seem that the panelinsts didn't explore the deep, underlying, issues (but then, for that you read LtU).

Still, some of you might want to check out this article for yourselves.

End Users to Shape Effective Software

This might be an interestng project to keep an eye on.

The papers seem to cover a wide range of topics relevant to end user programming in a variety of settings.

The 90 Minute Scheme to C compiler

90 minute video presentation from Marc Feeley, along with accompanying PowerPoint slides and source code, for a Scheme to C compiler. Good discussion of continuations and closures, as well as some dipping into the area of compiler construction.

How to write a simple Scheme to C compiler, in Scheme. In only 90 minutes! And although not supporting the whole Scheme standard, the compiler supports fully optimized proper tail calls, continuations, and (of course) full closures. The compiler is implemented using two important compilation techniques for functional languages: closure conversion and CPS-conversion.

The emphasis is on the 4 major problem areas that crop up in an attempt to convert Scheme to C:

  • tail-calls a.k.a. tail-recursion opt.
  • first-class continuations
  • closures of indefinite extent
  • automatic memory management i.e. GC

The solution presented gives a series of source-to-source transformations. Stage 1 of the compiler expands the 'let' forms in the Scheme code. Stage 2 converts continuations to CPS. Stage 3 converts the code to closures using encapsulated closure objects. Stage 4 is not presented but touches on how the results would lend itself to a GC implementation.

Call-by-Name, Call-by Value and the Lambda Calculus

Gordon Plotkin's Call-by-Name, Call-by-Value and the Lambda Calculus (Theoretical Computer Science , Vol. 1, pp. 125-159, 1975), is available online.

The fundamental point made in the paper should seem natural to most LtU readers: In order to reason about programming language semantics one should look for programming language/calculus pairs.

The paper contrasts CBN and CBV, and shows the differences between the Lambda Calculi appropriate for describing each of them.

Cache decorator in python 2.4

Yet another simple example of decorators in Pyhton (via Daily Python-URL).

Microsoft and DSLs @ OOPSLA

Microsoft gave a demo of their Software Factories & DSL tools and philosophy over at OOPSLA. It would be great to see the slides but as far as I can see they aren't available online.

I want to love the DSL approach, but I still haven't seen enough examples and detailed discussion to be convinced.

I'd be happy to hear what others think about the UML vs. DSL controversy.

Static Analysis for Security

An article from IEEE Security & Privacy magazine.

The article is an accessible introduction to the idea of static code analysis. Several security-related tools are described.

I guess it's tool-week here on LtU what with Dialyzer, JFluid and now this...