The LambdaVM pro­ject is actu­ally a really bril­liant pro­ject. It’s a modi­fic­a­tion of GHC to tar­get the JVM. I installed it in Octo­ber of last year and played around with it, feel­ing that it might actu­ally have a place in help­ing spread the gos­pel of Pola.

The thing is I can’t expect people to down­load the source to Pola if they want to play around with it, so I have to provide pre-​​compiled bin­ar­ies. OS X, Win­dows and Sol­aris are easy for me to pro­duce bin­ar­ies for, but then you have to think about Linux, BSD, OpenSol­aris, 64-​​bit Win­dows, etc., on vari­ous plat­forms. Tra­di­tion­ally I have about 6 or 7 bin­ar­ies up there for the most pop­u­lar archi­tec­tures — past releases have been most pop­u­lar with x86 Debian and x86 Win­dows — but every time I make a new release I have to rebuild them all.

So I was hop­ing to have a JVM ver­sion of Pola to put up there as a catch-​​all for archi­tec­tures I hadn’t had a chance to build for yet. While the LambdaVM pro­ject has treated me fant­ast­ic­ally well for little toy examples, it doesn’t do well for Pola. I tried it and it crashed after about 2 minutes after run­ning out of heap space. The stack trace showed it was still doing type inference…after two minutes…some­thing which Pola nat­ively com­piled does in less than a hun­dredth of a second.

I’m sure if I fiddled around with it I could get it sort of work­ing, but it doesn’t seem like a good use of my time, espe­cially since the end res­ult will be huge — the JAR file is 18MB, com­pared to 2MB for an uncom­pressed bin­ary — and many orders of mag­nitude slower and since I still have hopes of gradu­at­ing soon.

Still, the LambdaVM pro­ject is pretty awe­some. I hope it ends up kick­ing some ass.

The LambdaVM project is actually a really brilliant project. It's a modification of GHC to target the JVM. I installed it in October of last year and played around with it, feeling that it might actually have a place in helping spread the gospel of Pola. The thing is I can't expect people to download ...

I still have a few minutes before 2010 so I thought I’d write a little some­thing while Jasna and I are sit­ting on the couch watch­ing cel­eb­ra­tions on TV with her parents.

Well, first off I think I need to take more pic­tures, the evid­ence for that being that the above is my favour­ite pic­ture I took this year. It’s our fat­test cat, Pin­cho.
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I still have a few minutes before 2010 so I thought I'd write a little something while Jasna and I are sitting on the couch watching celebrations on TV with her parents. Well, first off I think I need to take more pictures, the evidence for that being that the above is my favourite picture ...

I recently rewrote the build sys­tem for Pola from ant to GNU make. Keep­ing things in ant was get­ting to be too much work, try­ing to be proper and writ­ing tasks (in Java) rather than just using the shell. I was ini­tially a little wor­ried about how much work it would be to redo the build sys­tem, but I was pleas­antly reminded by how simple it is. It took prob­ably about a quarter the amount of time to rewrite the entire build sys­tem from scratch in make than it would have taken to do a little incre­mental change to the ant sys­tem. As a bonus I man­aged to clean up the pro­ject a lot, redu­cing the build sys­tem down to just two files of a com­bined 70 lines. (more…)

I recently rewrote the build system for Pola from ant to GNU make. Keeping things in ant was getting to be too much work, trying to be proper and writing tasks (in Java) rather than just using the shell. I was initially a little worried about how much work it would be to redo ...

First, some excit­ing news that I’ve added the Pola pro­ject as my first pro­ject. There is a Sub­ver­sion repos­it­ory for it as well. We’ve been talk­ing about get­ting a site set up around Pola, with examples and user’s guides and maybe some inter­act­ive fea­tures, so this is a very small first step towards that.

Code-​​wise, what I’ve been work­ing on lately is finally try­ing to do bounds infer­ence prop­erly in the imple­ment­a­tion. The bounds infer­ence still isn’t entirely done and what’s there still isn’t work­ing entirely per­fectly, but it is excit­ingly close! Type in any well-​​typed func­tion which relies only on induct­ive data types and it will give you poly­no­mial bound on the run­ning time! Coin­duct­ive data types will come soon.

In an effort to mak­ing my “bor­ing” research blog more inter­est­ing, I’ve now even got a screen­shot! Is code any more excit­ing when it’s in screen­shot form?

The biggest prob­lem I’ve had so far is writ­ing my own Poly­no­mial data type in Haskell. I don’t even need any­thing fancy: I need addi­tion, sub­trac­tion and mul­ti­plic­a­tion of poly­no­mi­als over arbit­rary vari­ables. Sadly I haven’t found any­thing suit­able and had to build my own. I’m a little out of my depth here: it would be a pretty big under­state­ment to say that I’m ignor­ant when it comes to com­puter algebra. It’s a vir­tual cer­tainty that I’m doing my data rep­res­ent­a­tions and arith­metic oper­a­tions in the least effi­cient way pos­sible. But I can’t worry too much about; this isn’t really what my research is about.

If I find time today I think I’ll go through some com­puter algebra sys­tems to find one which has a suit­ably free licence and has a reas­on­able For­eign Func­tion Inter­face (so that I can use it pain­lessly from Haskell). Does such a thing exist?

First, some exciting news that I've added the Pola project as my first project. There is a Subversion repository for it as well. We've been talking about getting a site set up around Pola, with examples and user's guides and maybe some interactive features, so this is a very small first step towards that. Code-wise, ...