The PADL Report

I arrived on Philadelphia on Thursday (2012-01-19) evening. This was,
deliberately, two days before POPL and it's co-located events where due to
start. Hopefully this would give me a couple of days to recover from jetlag
and the general tiredness associated with flying for 20+ hours across 8
timezones (actually over the pacific you cross 16 but 24-16=8 count towards
jetlag) This seemed like a good idea, I was outside during daylight hours where
light would reach my retinas and produce the right chemicals in my brain to
reset my body clock - this is how all humans work, it's not related to my poor
vision.

So on the Friday and Saturday (of which you can see many photos) I felt awake,
but on Sunday and Monday when the conference begun and I was sitting down
indoors; I found myself falling asleep in many of the presentations. Sadly I
don't remember any of the presentations from VMCAI on Sunday, I don't even
remember what VMCAI was about! I also felt unwell and had a sore thought, I
think I had caught a cold.

On Monday Practical Aspects of Declarative Languages (PADL) begun. While I
sometimes fell asleep in the presentations I remember some of my favorites:

Vincent St-Amour, Sam Tobin-Hochstadt, Matthew Flatt and Matthias Felleisen
Typing the Numeric Tower

This paper described how to use a strong type system such as Haskell's with a
numeric tower such as Scheme's. It may have been my favorite from PADL but
that's not a fair statement since PADL ran on Monday and Tuesday but I was too
sleepy on Monday to pay attention to the speakers. I have the book of
proceedings (which is how these things work) so I can read any of the papers.

Other papers that deserve a closer look are:

Pablo Chico De Guzm?n, Amadeo Casas, Manuel Carro and Manuel Hermenegildo
Segment-Swapping Approach for Executing Trapped Computations

This paper fixes a problem with and-parallelism in Prolog. As I understand it
the problem is caused because of Prolog's nondeterminism. As such this is a
solution to a problem that we don't have in Mercury - and I'm not concerned
with parallelism in Prolog.

Christian Theil Have and Henning Christiansen
Efficient tabling of structured data using indexing and program
transformation

Another Prolog paper. This paper showed that tabling can lead to quadratic
behaviour in linear-looking code (such as append/3). I spoke with the author
about the problem, and now understand it. The author noted that Mercury
doesn't have this problem and asked me to explain why, which was pretty
straight forward.

I'll write-up my notes from POPL and DAMP later.

Downtown Philadelphia (2nd st)

Very annoyed!

So POPL ran a student presentation session. This is much like an
elevator pitch session, these are normally good, this one was ran as a
competition and included a prize.

The catch? You were restricted to 12 slides and 20 seconds per slide,
a total of 4 minutes. A time limit is not normally a problem, but the
rest is just too restrictive. It gets worse you may not use prose or
billeted lists, just pictures.

This means using 12 pictures that are relevant, which is difficult.
While all this is bad it's not the worst part.

I fucking missed out on dinner. By the time the qualifying rounds were
over all the food at the reception had been eaten!! POPL! You owe me
a dinner!!

I'm tired of this patronizing attitude to student's effort! "hey you
student! Jump through this hoop and maybe you'll get a pat on the
head!". Seriously, is a small bag of pretezels and a ballpoint pen
adiquite compensation for this effort and missing out on dinner!?!

Joan of Arc

Apparently this is the original and the coppy is in France. I'm taking
this with a grain of salt though.

The thinker

Snow!

I woke up this morning to find snow everywhere. The news was showing
trucks full of salt and plows ready to clear the roads. The footpaths
were also cleared, well most of them. A couple of times I crossed the
road to find no path on the other side. One time a police car pulled
up to tell me to cross back over, He assumed that I couldn't see that
the footpath was burried in snow and that I would find myself walking
in traffic instead.

Liberty bell

The liberty bell, originally the state house bell, became an important
symbol after becoming cracked. It's popularity further increased after
the American civil war.