Sunday, November 23, 2014

EclipseFP 2.6.2 released!

I've just released EclipseFP 2.6.2. This is mainly a bug fixing release with a better handling of cabal sandboxes and related functionality. It wraps also an important change in scion-browser, which should now mean that Hoogle uses all the packages present in your sandbox, so should give better results.

Browse the release notes!

Install by pointing your eclipse to

This release is brought to you by me, myself and I. I would love to see more people contribute, even if only to install the development versions to provide some testing before the release, or write some documentation. There's work that can be done on the Haskell side, on the Java side, etc. Contact me if you're not sure, or send me pull requests! The code is at and

Happy Haskell Hacking!!

Friday, September 19, 2014

A new Haskell IDE!

Well, that title is click-bait. It's only a proof of concept, so far (-:, sorry!

I wanted to play with Threepenny-GUI since it allowed to do UI the FRP way, without having the troubles of getting a proper UI library to work. And I was going through a period of frustration with EclipseFP, so I thought about something else for a while... It's got the romantic name of HWIDE!

So in fact, this is a very simple integration of CodeMirror and Threepenny-GUI, to be able to edit Haskell sources inside your browser. When you save your buffer, the data is written to disk, and if a cabal file could be found for that source file, a cabal build (in a sandbox) is attempted (with a configure if needed). The output is then parsed by code ripped off BuildWrapper, and the errors/warnings are displayed, so you can click on them and see the offending line in the code.

That's all, really, and even that is not 100% perfect, but it's a start. I could get to play a bit with Events and Behaviors, develop some little widgets. If some FRP experts want to have a look at the code and offer some advice, I'd be all ears!

I probably won't have much time to turn this into the next generation Haskell IDE, but please fork and hack to your heart's content! The repository is at

Happy Haskell Hacking!

Thursday, September 18, 2014

Learning Scala via unit tests

Last month I followed a big data training session, and we used Scala to write algorithms for Spark. I had looked at Scala some years ago but I think at the time the Eclipse support wasn't very good (the pot calling the kettle black, eh?), and it piqued my curiosity again. So I started looking at tutorials, and found Scala Labs. The idea is interesting: you get a project with sources and tests, and you need to make all the tests pass. The source code for both the code to change and the unit tests is heavily documented, and guides you through the language nicely. And seeing the green ticks appear always triggers the proper reward areas of my brain (-:

I had a little issue getting the code to compile using Eclipse, since there's a sbt-launch-0.13.0.jar library at the root of the project, and Eclipse used that as the top library, and it had a weird version of the List class, that wasn't genericized! I removed that jar from the class path and everything worked fine.

I'm not aware of a similar tutorial for Haskell, but that would be a good idea!

Monday, August 18, 2014

Fame at last!

I was reading the book "Haskell Data Analysis Cookbook" when suddenly, my name pops up! Funny to see a link to a 7 year old blog entry, who knew I would go down in history for a few line of codes for a perceptron? It's deep in Chapter 7, for those interested. Maybe this is a sign that I should abandon everything else and spend my time on AI, since it's obviously where fame and riches abound! Right...

Tuesday, July 22, 2014

EclipseFP 2.6.1 released!

I've just released EclipseFP 2.6.1. EclipseFP is a set of Eclipse plugins for Haskell development. This is a bug fixing release, mainly for GHC 7.8 support.

Release notes can be found here.

As usual, download from

Happy Haskell Hacking!

Sunday, July 20, 2014

BuildWrapper/EclipseFP and GHC 7.8

I've been working on some issues related to GHC 7.8 in BuildWrapper and EclipseFP. On the EclipseFP side, mainly the quickfixes are affected, because EclipseFP parses the GHC error messages to offer them, and the quotes characters have changed in the GHC 7.8 messages.

On the BuildWrapper side, things are more complex. Adapting to API changes wasn't a big deal, but it seems that GHC bugs involving the GHC API, static linking and other unknowns cause some things to break. The solution I've found was to build BuildWrapper with the -dynamic flag. But I couldn't upload this to hackage because Cabal thinks that -dynamic is a debug flag (it starts with d). I've sent a bug fix to Cabal, so in the next release that'll be fixed. So if you're using GHC 7.8 and BuildWrapper, you may want to rebuild the executable with -dynamic (uncomment the relevant line in the cabal file).

Note: BuildWrapper comes with a comprehensive test suite (90 tests covering all aspects). So you can always build the tests and run them to ensure everyting is OK on your system.

Happy Haskell Hacking!

Saturday, June 28, 2014

EclipseFP reaches 100 stars!

This week, the EclipseFP github project reached a hundred stars! Thanks to all users and contributors!! I know still a lot of work is needed to make EclipseFP even better (and faster (-:), so please do not hesitate to participate, on the Eclipse side, on the Haskell side, or on the documentation!

Happy Haskell Hacking!