Favorite MSDN article title of the month: NamedGZipStream, Covariance and Contravariance.
That's Microsoft, as always, blending the sublime and the ridiculous.
(Thanks also for the bogus etymology of "covariance": "In mathematics, covariance is a measure of the degree to which two variables move up or down together. The term was co-opted by the OO crowd to describe..." Way to overlook category theory, guys!)
A note on compiling Haskell to JavaScript, and interfacing with the DOM, in Yhc.
Herewith I'm making available the slides from the lunchtime talk I gave at Amazon's Edinburgh office last week (16 March 2007). Thanks again to Andrew Birkett for inviting me.
It might be hard to gather much information from these slides without the accompanying performance, but you might enjoy looking at the drawings or trying to run the code samples.
A recent tech report from Berkeley surveys the state of parallel computing [via Tim Bray]—particularly with an eye to the importance and difficulty of coding for multicore processors (one of which is helping me author this article). The bulk of the article deals with hardware design but also discusses programming systems (that's my bailliwick) and application design issues.
I've not read the whole thing yet, but I've already found some surprises:
These locking schemes are notoriously difficult to program, as the programmer has to remember to associate a lock with every critical data structure and to access only these locks using a deadlock-proof locking scheme. Locking schemes are inherently noncomposable and thus cannot form the basis of a general parallel programming model. Worse, these locking schemes are implemented using spin waits, which cause excessive coherence traffic and waste processor power.Transactional memory seems like a clear win, though it's not widely implemented and needs to get some experience behind it.
We believe that future successful programming models must be more human-centric. They will be tailored to the human process of productively architecting and efficiently implementing, debugging, and maintaining complex parallel applications on equally complex manycore hardware.This seems to me quite wise, although it's still unclear whether we can understand the cognitive (or psychological) processes in programming well enough to design for them.
Section 5.4 seems a haunting parable for language designers:
Programming languages, compilers, and architectures have often placed their bets on one style of parallel programming, usually forcing programmers to express all parallelism in that style. Now that we have a few decades of such experiments, we think that the conclusion is clear: some styles of parallelism have proven successful for some applications, and no style has proven best for all.
There seems to be a lot of wisdom collected here, which cuts across subfields of CS—as in a list of which "dwarfs" are commonplace in which application domains. This appears to be a quite useful reference for those of us who don't work in any particular application domain but make systems for programmers to use. I nudge you gently in the direction of this article.
Sun has gone and crammed a load of computers into a shipping container and is selling it. According to the New York Times: "The system includes sensors to detect tampering or movement and features a large red button to shut it down in an emergency."
Thweet.
-I argument to tell it where to look. TEXINPUTS environment variable can be used to control where it looks, but if you don't know the secret, you'll think you have to include every standard TeX directory as soon as you use this variable. TEXINPUTS with a colon means "include all the standard directories." $HOME/texmf. It is wise to put your downloaded packages in there, if you know the second secret. $HOME/texmf. And even though TeX keeps an ls-R file to index all those files (use texhash to update the index), it ignores the ones that aren't exactly where it's expecting them.
TFM files:texmf/fonts/tfm/fontXX.tfm
Bitmap (PK) fonts:texmf/fonts/pk/print-driver/fontXX.YYYpk
Style files:texmf/tex/generic/*
Font alias mapping:texmf/fontname/texfonts.map
chess package, automatically installs its files under the directory of my choice, using a certain hierarchy within that directory, but it is not the hierarchy TeX is expecting. chess package is over ten years old, and when you run it, you get a warning about "using babel with an old interface," also warning you not complain if you get further errors. You get further errors, but you can ignore them. xdvi uses by telling it xdvi -mfmode :600 (your resolution in place of 600). You cannot, in any easy way that I've been able to dvine, tell METAFONT to generate fonts in the same resolution that xdvi expects by default.