Sunday 14th March 2010

I'm collecting information (or at least links) about functional programming languages on the the JVM. I'm going to intentionally leave "functional programming language" undefined here, so that people can have fun debating :).

Functional Languages

• scala
• clojure
• CAL
• sisc
• OCaml

Languages with functional features

• jruby
• jython

Projects and rumours.

• There has been discussion about making the jhc target the jvm. They both start with 'j', so that is hopeful.

• Java itself may (soon? eventually?) support closures

While writing the post about performance, I got interested in Template Haskell, specially in the $(lift) construction.  Investigating a little bit about it, I got to the following code:

{-# LANGUAGE TemplateHaskell #-}

import Language.Haskell.TH.Syntax
import X

main :: IO ()
main = print $(lift $ x)

With X.hs:

module X where

import System.IO.Unsafe

x :: Int
x = read $ unsafePerformIO $ putStr "Number: " >> getLine

The result was a surprise to me. It asked for the number in compilation time.

$ ghc --make main
[2 of 2] Compiling Main             ( main.hs, main.o )
Loading package ghc-prim ... linking ... done.
Loading package integer-gmp ... linking ... done.
Loading package base ... linking ... done.
Loading package array-0.3.0.0 ... linking ... done.
Loading package containers-0.3.0.0 ... linking ... done.
Loading package pretty-1.0.1.1 ... linking ... done.
Loading package template-haskell ... linking ... done.
Number: 5
Linking main ...
marcot@zezinho:~/codigo/haskell$ ./main
5

That’s right: I am taking the train uptown to my old romping ground, Columbia University, for Debconf10. I am supremely and superbly excited as I tend to really like these events, so much so, that I am also pretty involved with the organizing team.

For those on the edge of a decision, here are a few thoughts that might push you toward the edge of “f*ck yea, I am gonna go!”

So one important, one of the MOST important parts of the conf is the venue and Columbia University is a fantabulous venue. In fact, it is the only great venue, imho, in all of Manhattan so I was pretty thrilled (and relieved) to hear that it was secured.

It is an oasis in an otherwise bustling city. And better, a compact oasis where everything is nestled and close to each other, within like 3 minutes walking distance of each other. Even better is that the grounds and architecture are quite beautiful and charming. There are these majestic stairs, “the steps” where you can soak in the sun, great lawns for tossing a Frisbee, wonderful and smaller patches of lawn behind old school red brick buildings, and statutes, one of which is great for climbing on to sit and contemplate the day or night or just life, as I used to love to do. It is a great campus for staying up late and watching the sun rise. My fondest times was when the campus was blanketed under a mountain of snow, but it is pretty nice over the summer as well.

We have also secured an all night hack lab, which is a pretty essential touch.

We are also thinking beyond the venue, concocting and expanding ideas for contributions, a great day trip (that will likely not entail a bus but a beach, lots of Russians, roller coasters, and even baseball, oh and lots of NY Kitsch), and there are many other ideas swirling around. We are about to release the call for contributions so you will learn more, including some information on how to brainstorm with us, so be on the look out and remember to register if you’ve made your decision!