OCamlcore Planet

FP-Sydney: FP-Syd #22.

Sat, 13 Mar 2010 00:57:00 +0000

On Thursday February 25th we held the first meeting for 2010 of the Sydney Functional Programming group. The meeting was held at Google's Sydney offices and we had 17 people show up to hear our two presenters.

First up we had your correspondent (Erik de Castro Lopo), giving a presentation titled "Hacking DDC" on my bug fixing work on Ben Lippmeier's DDC compiler. I explained a little about what DDC and Disciple were; a Haskell like language with some interesting extensions to the type system. I then suggested that anyone curious as to why these extensions were interesting should read the first chapter of Ben's PhD thesis "Type Inference and Optimisation for an Impure World". I then went on how using Darcs for the revision control made it easy to use one branch per bug or feature I'm working on, specifically, it allowed me to work on one until I got stuck and then move on to another without the debugging of the first interfering with the second.

Our second presenter for the evening was Tim Docker who gave us an explanation of a Domain Specific Language (DSL) for handling dates in financial systems. Code written in his DSL looked a lot like Ocaml, but the implementation was in C++.

A big thanks to Tim for presenting and Google for providing the meeting venue and the snacks.

OCamlCore Forge News: CCSS 1.1 released

Fri, 12 Mar 2010 04:38:10 +0000

This version adds support for unit conversion. This feature is off by default; please provide command line option '--convert' (short version '-c') to activate it.

Erik de Castro Lopo: Intel Embedded Graphics Driver Fail.

Thu, 11 Mar 2010 10:00:28 +0000

In my day job I do Linux embedded work and as people in the embedded world know, Linux is a pretty commonly used embedded OS. Today I was evaluating a new board and found it had an Intel graphics chip that was not properly detected by Ubuntu 9.10. The ever trusty lspci said this:

  00:02.0 VGA compatible controller: Intel Corporation System Controller Hub
        	(SCH Poulsbo) Graphics Controller (rev 07)

We all know that Intel employs a bunch of well known Xorg developers, so this shouldn't be a problem, right?

Unfortunately, it is a problem. Intel's offering for this chipset is the Intel® Embedded Graphics Drivers web page where they offer a 124 megabyte download (registration required). After registration you get to choose which driver pack you want and which OS you are downloading it for. Ubuntu was not on the list and neither was Debian. I chose Fedora 10 (released in 2008) as that was the most recent one.

Now, you can image my surprise when the driver download for Fedora Linux contained just four files:

  Archive:  /tmp/IEGD_10_3_GOLD.zip
      testing: UsersGuide_10_3_1525.pdf   OK
      testing: IEGD_10_3_GOLD_1525.exe    OK
      testing: IEGD_SU_10_3_GOLD.pdf      OK
      testing: RELNOTES_10_3_1525.txt     OK
  No errors detected in compressed data of /tmp/IEGD_10_3_GOLD.zip.

Yep, thats right, the driver download for Fedora Linux contains two PDF files, a text file and an executable installer for Windows.

Being the curious (and paranoid) type I decided to explore this further, by running the installer under WINE in a chroot. After the installer you get left with several metric craploads of Java Jar files, and another windows executable iegd-ced.exe that supposedly configures this nightmare. I ran it (again, under WINE in a chroot) but it didn't seem to do anything sensible or worthwhile so I looked around amongst the other installed files and found IEGD_10_3_Linux.tgz.

Inside that tarball there are a bunch of Xorg library binaries (for several different versions of Xorg), a large chunk of source code that gets compiled into the Linux kernel and even better yet, a couple of Microsoft Visual Studio project files. WTF?

Unbe-fscking-lievable. Needless to say, I will avoid any hardware which uses this chipset and any other hardware that requires binary only kernel blobs packaged this badly. Doing so makes my life easier.

The people at Intel who thought this was a good idea must have their own personal mother-lode of stupid.

The Caml Humps: CCSS 1.0

Thu, 11 Mar 2010 07:01:13 +0000

CCSS is a preprocessor/pretty-printer for CSS (Cascading Style Sheets). It extends the CSS language with support for declaration of variables and basic arithmetic operations (addition, subtraction, multiplication, division). The programme is supposed to be used as a filter: it reads the CSS source from stdin and outputs its result on stdout.

The Caml Humps: OCaml Batteries Included 1.1.0

Thu, 11 Mar 2010 06:44:49 +0000

Batteries Included is a candidate standard development platform for OCaml.

OCamlCore Forge News: CCSS 1.0 released

Thu, 11 Mar 2010 04:48:16 +0000

CCSS is a preprocessor for CSS, extending the language with arithmetic operations and the possibility to declare and use variables. This is the first public release of the project.

Sylvain Le Gall: LLVM, OCaml and Debian

Wed, 10 Mar 2010 18:07:37 +0000

I hope some people from the OCaml community will enjoy this changelog, extracted from llvm 2.6-7, which has just been uploaded:

  [ Arthur Loiret ]
   
  [...]

  [ Sylvain Le Gall ]
  * Build a libllvm-ocaml-dev package, which contains the OCaml binding:
    Closes: #568556.
    - debian/debhelper.in/libllvm-ocaml-dev.{dirs,doc-base,install,META}: Add.
    - debian/control.in/source: Build-Depends on ocaml-nox (>= 3.11.2),
      ocaml-best-compilers | ocaml-nox, dh-ocaml (>= 0.9.1).
    - debian/packages.d/llvm.mk:
      + (llvm_packages): Add libllvm-ocaml-dev.
      + (libllvm-ocaml-dev_extra_binary): Define, install META file.
    - debian/rules.d/binary.mk: Add dh_installdirs and dh_ocaml.
    - debian/rules.d/vars.mk:
      + include /usr/share/ocaml/ocamlvars.mk.
      + Configure with --with-ocaml-libdir=$(OCAML_STDLIB_DIR)/llvm.
  * debian/rules.d/build.mk: Fix symlinks pointing to the $DESTDIR.

In other words: LLVM is now built with its OCaml bindings and a META file for findlib. It will take some days before reaching every architectures, but hopefully it will be in Squeeze (next Debian stable release).

Thanks to Arthur Loiret for the quick upload.

Caml Weekly News: Caml Weekly News, 09 Mar 2010

Tue, 09 Mar 2010 12:00:00 +0000

gc overhead / MetaOCaml lives! / Encoding an extensible parse tree and subtyping within OCaml / NaCl/OCaml (OCaml as a client-side web programming language) / Commercial Users of Functional Programming - call for participation / Other Caml News

Romain Beauxis: Liquidsoap-full 0.9.2-2 and ocaml-cry 0.1.2

Mon, 08 Mar 2010 23:13:43 +0000

An issue with the new ocaml-cry module that replaces the shout library has been recently discovered.

This issue was related to the data sent to the icecast server and could result in a higher load and loss of data when sending data to the server.

We have released a new version of ocaml-cry that fixes this issue, numbered 0.1.2.

We have also released a new liquidsoap-full tarball, numbered 0.9.2-2 and now available in the download section on sourceforge.net.

Additionally, our custom stable packages have been rebuild against this new version, both for the i386 and the amd64 architecture.

The package available in Debian sid/unstable is now built against the fixed ocaml-cry as well.

We recommend that any user that uses liquidsoap 0.9.2 updates its liquidsoap to make sure it uses ocaml-cry 0.1.2.

Please note that ocaml modules are not dynamically loaded, so you need to rebuild liquidsoap against the new ocaml-cry if you are building from source.

Stefano Zacchiroli: ocaml batteries included 1.1.0 is in debian now

Sat, 06 Mar 2010 15:39:15 +0000

OCaml Batteries Included 1.1.0 has arrived in Debian

I've just uploaded the Debian package of OCaml Batteries Included 1.1.0 to the Debian unstable archive; hopefully, it will quickly enter testing to be released with the next Debian stable release. This is the first release in Debian of the "new generation" of Batteries Included, which has followed a strict diet, and now has Camomile as its only external dependency.

It took me a while to package it due to an intertwining transition to OCaml 3.11.2 (during which we have fleshed out the last remaining few bits of transition to our new dependency system). Also, I had to fix some typical build issue with upstream, which kindly coordinated with me to have the fixes included in 1.1.0.

So go, enjoy Batteries 1.1.0, and let me know your feedback:

    # apt-get install ocaml-batteries-included

(check that it will install 1.1.0 though, it might take a few days to hit your favorite architecture and mirror)

Tip: starting from this version you will need the following to use Batteries in place of the legacy standard library in your sources:

    open Batteries_uni

for multi-threaded programs you should rather use open Batteries. Check the FAQ file installed under /usr/share/doc/libbatteries-ocaml-dev/ for more quick start information.