Lambda the Ultimate

A 7-hour lecture given at TECS Week 2005 by Xavier Leroy.

This detailed set of slides explains various security models, and related attacks.

It has been awhile since we discussed mobile code and its security implications, but I am sure everyone realizes this is a major issue, that will only become more important as network applications become more and more pervasive (e.g., via mobile phones).

Some of you might be interested in subtext, a project that explores the idea of example centric programming and non-textual programs.

The basic idea is that the representation of a program is the same as its execution (possibly related to the discussion currently going on about edit-time, reasoning-time etc.)

Programs are constructed by copying and executed copy flow: the projection of changes through copies.

If all this sounds intriguing, hop over and take a look. The site hosts a couple of demos and papers that provide more details.

by Jim Gray, via Joe Armstrong and apropos Crash-only software.

An analysis of the failure statistics of a commercially available fault-tolerant system shows that administration and software are the major contributors to failure. Various approaches to software fault-tolerance are then discussed -- notably process-pairs, transactions and reliable storage. It is pointed out that faults in production software are often soft (transient) and that a transaction mechanism combined with persistent process-pairs provides fault-tolerant execution -- the key to software fault-tolerance.

Link

During a discussion on the subject of passion in programming, David Bremner on #haskell pointed out Richard Hamming's 1986 talk You and Your Research. Here's a taste:

At Los Alamos I was brought in to run the computing machines which other people had got going, so those scientists and physicists could get back to business. I saw I was a stooge. I saw that although physically I was the same, they were different. And to put the thing bluntly, I was envious. I wanted to know why they were so different from me. I saw Feynman up close. I saw Fermi and Teller. I saw Oppenheimer. I saw Hans Bethe: he was my boss. I saw quite a few very capable people. I became very interested in the difference between those who do and those who might have done.

Hamming clearly describes both the difference between the two and how you can be one of those who do.

NewScientist.com:

A computer-assisted proof of a 150-year-old mathematical conjecture can at last be checked by human mathematicians... ...Georges Gonthier, at Microsoft's research laboratory in Cambridge, UK, and Benjamin Werner at INRIA in France have proven the [Four Colour Theorem] in a way that should remove such concerns.

They translated the proof into a language used to represent logical propositions - called Coq - and created logic-checking software to confirm that the steps put forward in the proof make sense.

Georges Gonthier's home page includes links to the paper and the actual proof.

The Sixth IBM Programming Languages Day will be held at the IBM Thomas J. Watson Research Center on Friday, April 22, 2005. The day will be held in cooperation with the New Jersey and New England Programming Languages and Systems Seminars. The main goal of the event is to increase awareness of each other's work, and to encourage interaction and collaboration.

Simon Peyton Jones is keynoting on composable memory transactions.

The program, and abstracts, are available online.

The documents on this page consolidate a possible amendment to Ada 95 with Technical Corrigendum 1 and the Ada Standard (International Standard ISO/IEC 8652:1995). The Amendment will be produced by the ISO/IEC JTC 1/SC 22/WG 9 Ada Rapporteur Group (ARG). The final form of the Amendment, or whether its standardization will succeed, are not known at this time. Thus, any proposed feature may be substantially changed or withdrawn before the Amendment begins standardization. These draft documents are not an official publication or work product of the ARG, but rather are provided by Ada Europe as a service to the Ada community.

Ada is a quite well designed language (despite having quirks like any other language, of course). The design process is impressive, as you can see if you check the ARG website.

The next version of Ada is almost ready, and you can get a taste of what's coming up by reading the reference manual, or the Annotated Ada 2006 Language Reference Manual which includes more detailed language design reasoning.

Among the new things in Ada06 are: interfaces (as in Java), mutually dependent references between units and finer control over access from the private part of a package, standard library enhancements including a comprehensive container library, file and directory management etc. and extensive additions to the Real-Time Systems Annex.

The Real-Time Systems Annex which specifies additional characteristics of Ada implementations intended for real-time systems, and is one of Ada's strong points, now includes the Ravenscar profile for high-integrity systems, further dispatching policies such as Round Robin and Earliest Deadline First, support for timing events, and support for control of CPU time utilization.

CogPrints, an electronic archive for self-archive papers in any area of Psychology, neuroscience, and Linguistics, and many areas of Computer Science (e.g., artificial intelligence, robotics, vison, learning, speech, neural networks), Philosophy (e.g., mind, language, knowledge, science, logic), Biology (e.g., ethology, behavioral ecology, sociobiology, behaviour genetics, evolutionary theory), Medicine (e.g., Psychiatry, Neurology, human genetics, Imaging), Anthropology (e.g., primatology, cognitive ethnology, archeology, paleontology), as well as any other portions of the physical, social and mathematical sciences that are pertinent to the study of cognition.

I cite it here mostly because of CS/Language, but other categories are marginally related to PLT as well (I believe "cog" in the name of the site stands for "cognitive", and we used to discuss cognitive problems in the past ;-) ).

Some of our most read threads are our introductions to type systems, monads and continuations, so I guess it wouldn't hurt to start yet another getting started thread.

From time to time we have questions posted about how to start designing a language, or a DSL; I think it would be helpful to collect links to various resources that might help people trying to design their first (or second, or third...) language.

Resources may include design tips, methodological suggestions, detailed discussion of major features (e.g., how important is type inferencing) etc. Think of utter beginners, but also about language mavens with little language design experience.

Two requests: (1) Let's not to turn this into a thread about language implementation tips. We'll do that one later. (2) If we dicussed the papers you recommend in the past, give links to the previous LtU threads.

I don't think this survey is very important, but it wouldn't hurt to take a look.

The top 5 programming languages reported in use were C# (72%), Java (66%), Visual Basic (62%), C++ (54%) and JavaScript (50%).

This study was conducted among subscribers to Computerworld, a total of 966 qualified completed surveys were received.

The selection criteria used to choose among the subscribers of Computerworld (see methodology section at the bottom) are, of course, biased.