First things first: the paper sub­mit­ted to LCC has been put up on the Pola pro­ject page.

Secondly, one of my super­visors informed of the loom­ing dead­line for FOPARA (Found­a­tional and Prac­tical Applic­a­tions of Resource Ana­lysis), a work­shop of FM2009 in Eind­hoven. The work­shop seems like a bril­liant fit for my work and there are a lot of inter­est­ing people attend­ing (for instance Mar­tin Hof­mann as well as Hume people like Kevin Ham­mond and Greg Michael­son and many others).

The only stick­ing point is the dead­line, less than 3 weeks away. I think this would be a good oppor­tun­ity to write up the more prac­tical aspects of Pola, how it’s imple­men­ted and how a pro­gram­mer could use it. I’m already a little back­logged with imple­ment­a­tion details and, in my mind, fin­ish­ing up the new imple­ment­a­tion of bounds infer­ence is more import­ant than writ­ing another paper.

First things first: the paper submitted to LCC has been put up on the Pola project page. Secondly, one of my supervisors informed of the looming deadline for FOPARA (Foundational and Practical Applications of Resource Analysis), a workshop of FM2009 in Eindhoven. The workshop seems like a brilliant fit for my work and there are ...

The paper to LCC was accep­ted. I didn’t think it was a ter­ribly great paper — we have a per­sist­ent prob­lem of organ­iz­ing papers and decid­ing exactly what should be included and how it should be presen­ted — but the import­ant thing is that one of us will be head­ing to LCC. Our work is, to a large extent, an exten­sion of Mar­tin Hof­mann’s work and he will be present at LCC! It’s a great opportunity.

The paper to LCC was accepted. I didn't think it was a terribly great paper—we have a persistent problem of organizing papers and deciding exactly what should be included and how it should be presented—but the important thing is that one of us will be heading to LCC. Our work is, to a large ...

My under­gradu­ate super­visor (from the Uni­ver­sity of Cal­gary), Robin Cock­ett, was in town today on a short visit. My two cur­rent super­visors, Robin and I spent the entire day in a friendly research meet­ing. I sup­pose the biggest bene­fit was the every­one got to meet each other, but we also covered a lot of ground on Pola and what we should be focus­ing on.

The first big change is that we’re going to, again, redo peeks and cases. Peeks and cases have long been a prob­lem with Pola and one which is, so far as I know, com­pletely unique to Pola. In a typ­ical func­tional lan­guage, case con­structs are no mat­ter at all: you have some datum and you case on it to see what it is (is it an empty list or a non-​​empty list?) and go on your way. In Pola things are not so neat and tidy: cent­ral to the work­ings of Pola is the idea that often you’re not allowed to ref­er­ence a vari­able more than once (lest you break out of poly­no­mial time). This restric­tion can be waived, very del­ic­ately, if you prom­ise to only “peek” at a value but not use it. The dis­tinc­tion between a case (“con­sum­ing” a value) and a peek has always been a bit awk­ward, but also very dan­ger­ous to play with if you don’t want to acci­dent­ally allow non-​​polynomial things slip­ping in. I think we’ve finally figured out a good scheme.

The second big change is dis­cuss­ing how to the bounds infer­ence. This is a huge one because hav­ing the com­piler infer bounds is, in my mind, the raison d’être for Pola. I’m almost done imple­ment­ing very loose, clumsy bounds. They’re cor­rect as upper bounds, but they’re so loose as to be nigh use­less. There will never be a per­fect solu­tion to get­ting totally tight bounds and I’m becom­ing increas­ingly aware that there is a huge trade-​​off between being able to get tight bounds on things and hav­ing to carry around a lot of typ­ing inform­a­tion that allows you to infer those bounds. This is what I’ll be spend­ing most of my time on in the near future.

As for the prob­lem I men­tioned last time about hav­ing to imple­ment my own poly­no­mial arith­metic: I just rewrote it myself and I’m happy with it. It works and it’s much cleaner than before.

My undergraduate supervisor (from the University of Calgary), Robin Cockett, was in town today on a short visit. My two current supervisors, Robin and I spent the entire day in a friendly research meeting. I suppose the biggest benefit was the everyone got to meet each other, but we also covered a lot of ...

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, ...

I have finally found the motiv­a­tion to register my own domain (wiz​ard​like​.ca), which gives me a lot of flex­ib­il­ity in how I do things, but also con­sol­id­ates everything I want out of web services.

So far it’s just this blog, which replaces my old blog, and my soft­ware pro­jects site. Over the com­ing weeks and months the web­site will likely spread, at least into an image gal­lery, and maybe also into a gene­a­logy data­base and a teach­ing resources site. It’s also fant­ast­ic­ally nice to have my email, XMPP (Jab­ber), data back-​​up and repos­it­ory ser­vices under one domain.

I have finally found the motivation to register my own domain (wizardlike.ca), which gives me a lot of flexibility in how I do things, but also consolidates everything I want out of web services. So far it's just this blog, which replaces my old blog, and my software projects site. Over the coming weeks and ...