And guess what? Erlisp is one of the nine! I’m not exactly sure how this selection was made, but if it had anything to do with community feedback: thank you all for the support.

The other eight projects are:

• Lisp Sockets
  This is great! I have needed to use sockets on several occasions, and had to settle for non-portable solutions with SB-BSD-SOCKETS. Better yet, Erlisp will eventually need portable sockets as well.

  Now we “just” need a library and/or CLRFI to be able to serialize any Lisp object, send it to another Lisp implementation running on another computer, and deserialize it…

• Fetter - foreign function interface generator
  Generating foreign function interfaces automatically is a cool thing in itself, but this project promises to bring not just C but C++ support to the Open Source Lisp masses! Way cool! (Might it even get wxCL off the ground?)

• Axiom User Interface
  I know of 2 Common Lisp computer algebra systems; Maxima I’ve used, Axiom I haven’t. There is some cool stuff going on in the Maxima GUI camp, let’s see what this summer will bring for Axiom.

• Gene Ontology Database
  Not my cup of tea, but a cool example of how Common Lisp is being put to use.

• Hello-C, extending UFFI
  UFFI with callbacks, better documentation, and higher level abstractions… what more could we ask for? Also, it’ll serve as the basis for Fetter (mentioned above).

  [EDIT] I don’t know where I got that, but Fetter is NOT based on Hello-C (it’s based on UFFI). I guess that’s sensible, to make sure these projects can be developed in parallel.

• Extend PLT Scheme’s Stepper
  This would have interested me 2-3 years ago, but I’m off Scheme now. Still, nice to see they’re in on the action too.

• Unified low-level database drivers for PLT Scheme
  Ditto.

• A Stepper for Slime
  Last but definately not least: better debugging tools for SLIME. Any SLIME addition makes me happy, but this one will be especially well-appreciated.

1. From Erlisp’s download page you should get erlisp-snapshot.tar.gz. This file contains the source code in the Erlisp repository, and is updated whenever that repository is updated. Extract its contents somewhere. (Alternatively, you can check out the source code directly from the repository, as described here.)

   In your new erlisp directory, there should be the following:

   • LICENSE
     Contains Erlisp’s license (BSD).

   • erlisp.asd
     ASDF system definition for Erlisp.

   • doc/external/, doc/internal/
     Currently empty. Should hold external (user) documentation and internal (developer) documentation at some point.

   • src/
     Contains all actual source code. This directory will probably be subdivided into further subdirectories (and corresponding ASDF modules) when Erlisp grows.

   • test/
     This contains all automated FiveAM (unit) tests. At the moment, this is the closest thing to documentation there is.

2. To conveniently use Erlisp, you’ll need ASDF. Create a symlink to erlisp.asd from one of the directories in ASDF:*CENTRAL-REGISTRY*, or add the erlisp directory to that list.

3. Start SBCL, and load Erlisp using (asdf:oos ‘asdf:load-op :erlisp).

   If you’d like to run the automated tests, you’ll need to have FiveAM. Then you can use (asdf:oos ‘asdf:test-op :erlisp).

4. To see what you can do now that you have Erlisp loaded, have a look at the automated tests. Be careful though. Both the internal and external API are tested, so this doesn’t really show “what you’re supposed to be using”. I guess I should be making this distinction clear by exporting symbols from the ERLISP package, but I haven’t gotten around to that yet.

   So at the moment do (in-package :erlisp) and, as a rule of thumb, stay away from anything that isn’t SPAWN, CURRENT-PROCESS, SEND, RECEIVE, RECEIVE-WITH-MATCHER, or SET-DEFAULT-PATTERN-MATCHER.

If any non-SBCL users among you tried the above, you would have gotten a message like “Threads are currently only implemented for SBCL”.

The file src/compatibility.lisp makes sure that the rest of the code doesn’t have to depend on implementation specific features, but it is only implemented for SBCL at the moment. If you know the threads API of your Lisp, feel free to send me a patch. The download page describes how to check out the repository, make your changes, and send them to me in a patch. It’ll be much appreciated!

I’ve implemented (for SBCL):

• Processes as threads.

• Local message sending and receiving.

• API to plug in your own pattern matcher.

Apart from actually writing code, I’ve been taking steps to get development back on track:

• I’ve switched from GNU Arch to darcs for version control. Darcs is much easier to use, and in my opinion also conceptually nicer. (For example there is no difference between a working copy and a repository.) It’s the first version control system I like to use.

• To get more community interaction, I’ve started this blog, and there is now an Erlisp mailing list. Thanks to Mario Mommer of Common-Lisp.net for setting it up for me.

• I’ve written a little Bash script that:
  Synchronizes the main Erlisp repository with my local one.
  Uploads a new Erlisp snapshot tarball.
  Sends an e-mail to the mailing list about the new patches in the repository.

Other noteworthy events are:

• I’ve been contacted by Heow Eide-Goodman of Lisp NYC about Google’s Summer of Code. Apparently, Lisp NYC is a participating mentoring organization and they list working on Erlisp as one of their project ideas.

  I’m very flattered by all this, but I’m not sure whether I can mentor a student to work on Erlisp. I’m only figuring this stuff out as I go, so I’m by no means an expert, and I’m not exactly drowning in spare time either (not even during the coming summer vacation).

• As part of the website revamping I’ve made a (very primitive) search mechanism for the Erlisp reference section. There has also been a slow but steady stream of reference additions over the months.

• This blog has been added to Planet Lisp.