Saturday Morning Linkfest

Haskell

Stanford CS240h: Functional Systems in Haskell
Stanford is really pushing e-learning at the moment, what with the AI, machine learning and database classes that the engineering department is running. This is another good course with content available online.

Reddit: What does your company use Haskell for?
What it says on the tin: quite a few people chime in. Seems like Haskell isn’t so much of an “academic-only” language any more!

Storage and Identification of Cabalized Packages
Very helpful guide to GHC package management from Albert Lai.

Unused constraints in GHC
This week, we spotted an interesting thing in some of the diagrams code. There are a bunch of places where an earlier implementation of a feature required certain type class constraints. With a more recent implementation, that requirement has now gone away, but the constraints remain in the code. That makes using these particular functions trickier than it needs to be. We’d like for the compiler to warn about these extra un-needed constraints, since otherwise they just hang around like a bad smell. Brent describes it as “a nice project for someone wanting to dig into hacking on GHC”...

The other culture

Money (via Crooked Timber)
Where does it come from? There’s a nice little Just-So story that money arose naturally out of barter economies as a natural consequence of Immutable Economic Laws. It’s thus slightly embarrassing that anthropologists haven’t found any evidence at all for barter economies of the required type. Cue immense academic pissing contest, of course. Read it all. It’s good.

Cool stuff

Visual 6502
Remember the 6502? Come on, no need to be shy. The other 8-bit processor from the 1980s. I was a Z80 boy myself, but I did a bit of 6502 assembler programming back in the day (for my A-Level computer studies project, I wrote a little data capture package for an infra-red spectrometer in our school’s chemistry lab using the A/D ports on a BBC Micro). Any other fans of retro 8-bit should take a look at this site. They’re building sub-gate-level simulations and visualisations of old microprocessors. The visualisations are very neat, but the way they’re doing it is the kicker–working directly from dies, they’re photographing them, doing some image analysis to get the patterns of the chip layers out and using these to build transistor-level models of the chips. Lots of fun!

Circos
You may have seen those super sweet circular charts floating around in some biology papers in Nature or Science. This is where they’re made, and you can make them too.

Quasicrystal animations
This is “Haskell” too, but it lives in “Cool stuff”.