[Chicken-users] Chicken Gazette - Issue 2

[Moritz Heidkamp]

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--[ Issue 2 ]-------------------------------------- G A Z E T T E
                               brought to you by the Chicken Team


0. Introduction

Since the last issue of the Chicken Gazette, Moritz Heidkamp polished
the website compiler Hyde to produce the Chicken Gazette on the
call-cc.org server. From now on, all issues can also be read on the
web at http://gazette.call-cc.org. A nice feature is the addition of
an Atom feed to this site, so you can now point your favorite feed
reader to http://gazette.call-cc.org/feed.atom and get your weekly
update on Chicken delivered to your home! Thanks Moritz for this nice
piece of work.

Further kudos go out to Manfred Wischner who kindly granted us the use
of his beautiful chicken painting in the new Chicken Gazette logo. The
original version can be found at this address:
http://www.fotocommunity.de/pc/pc/mypics/604498/display/9937731


1. New Infrastructure - Final Cleanups & Salmonella As An Aid For Egg Authors

The move to our new infrastructure is almost complete now. With a fix
in Chicken's scheduler (see below), our fine webserver Spiffy now runs
without glitches (so far), serving all of http://call-cc.org/ to you.

Also Salmonella, our testing framework for extensions, caught quite a
few failing eggs. At the moment of writing we are down to 6. You can
check the latest salmonella reports for yourself at
http://tests.call-cc.org/current/salmonella-report/ and if you are an
egg author you can even setup an Atom feed for reports on your own (or
your favorite) eggs. As Mario Goulart put it:

  If you want to be notified when some egg breaks, you can subscribe to
  the egg feeds. They are updated when the the daily testing process
  fails.  If you have a Subversion account for the eggs repository,
  you can create a custom file for you which summarizes the status
  for all the eggs you want to follow. Take a look at one of the
  custom files under the salmonella-custom-feeds directory. They
  generate feed files at http://tests.call-cc.org/feeds/custom.


2. The Hatching Farm - New Eggs & The Egg Repository

The cleanup expanded over to the egg repository structure. Usually
Chicken eggs are stored in the conventional trunk/branches/tags
subversion hierarchy. Egg authors release an egg by tagging the trunk
with the appropriate version number. This version number is then used
by `chicken-install` and `henrietta` (the CGI script that runs on
call-cc.org and its mirrors to deliver eggs) to determine
dependencies. If an egg has not got a tag yet, the version is
displayed as `trunk`. As this makes it hard for other authors to rely
on an unversioned egg, Mario Goulart proposed the tagging and release
of all these eggs. Progress of this action can be tracked on the
bugtracker at http://bugs.call-cc.org/ticket/364.

Other than that, there was also some development going on:

awful (http://wiki.call-cc.org/egg/awful)

  Mario's awful web framework has seen the release of version 0.26.0
  this week. Apart from improvements and bugfixes (see the version
  history for details), there is now another screencast of Mario
  himself developing a simple Number guessing game and in its course
  demonstrating the fancy web REPL as well as his advanced number
  guessing skills. Find it at http://wiki.call-cc.org/video/awful-guess.ogv
  Definitely a must see!

hyde (http://wiki.call-cc.org/egg/hyde)

  Moritz' little static website compiler has been improved quite a bit
  to be able to handle the Chicken Gazette properly. Check out this
  issue's Omelette Recipes to see how it's done!


chicken-doc (http://wiki.call-cc.org/egg/chicken-doc)

  Version 0.4.0 of Jim Ursetto's priceless documentation exploration
  tool has been released this week, too. Note that if you want to
  upgrade from an older version, you need to re-initialize your
  documentation repository since its format has changed. See the
  documentation on how to do that.


Also note that the egg repository crossed revision 20000 this week
(the revision in question has been cunningly grabbed by a certain Mr Z, 
see http://bugs.call-cc.org/changeset/20000). Keep those commits
coming, everyone!


3. The Core - Bleeding Edge Development

Since Spiffy at http://www.call-cc.org was experiencing occasional
hangs after the infrastructure migration, a lot of investigative work
was done to track down the issue. Felix suspected the scheduler to be
the culprit and thus reworked it in the safer-scheduler branch which
got merged into the experimental branch this week. Testing of the new
scheduler is (as always) very welcome, especially if you have programs
at hand which make heavy use of threads, of course.

Another effect of the `safer-scheduler` Chicken seems to be a
significant performance improvement for Spiffy as Mario Goulart showed
by `wget`ting the complete GNU Emacs manual (687 individual files
totalling 6.3MiB) from it with the old and the new version. The
timings are impressive: about 11 seconds with the old version and only
1.5 seconds with the new one, or as Mario put it: "It's like removing
(sleep 8) from the code!" However, it is not yet entirely clear what
the cause of this performance boost is since the new scheduler is not
the only change that has been introduced in this branch so far. We'll
keep you posted about further insights on this topic.


4. Chicken Talk

One rather active discussion at chicken-users this week has been
started by Jim Pryor. Jim has packaged all eggs for Arch Linux a few
months ago and is now in the process of upgrading those to their
latest versions. However, he had a bit of trouble properly extracting
the required meta data from the eggs which lead to a discussion about
the state of packaging Chicken extensions for other package managment
systems in general as well as the clean up flurry mentioned above.

Another interesting thread has been started by Christian
Kellermann. He is asking about how to export functions from a Chicken
library which can be called from C. Felix and Thomas Chust chimed in
and gave some insightful advice.

On chicken-hackers there has been some activity regarding the plans of
founding a legal entity for the Chicken project. Christian Kellermann
had contacted Eric Kow of the Darcs project asking him about their
experience with the Software Freedom Conservancy
(http://conservancy.softwarefreedom.org/) and shared his reply with
us. Mario Goulart pointed out that the OpenEmbedded project uses a
German e.V. as its legal entity which might very well be an option for
the Chicken project, too.


5. Omelette Recipes - Tips and Tricks

This is the first installment of a new Chicken Gazette section which will
feature interesting Eggs and how to use them as well as general Chicken tips.

This week's featured egg is Hyde, the static website compiler which is
used to generate the new Chicken Gazette website. Its intent and use
are similar to those of Webgen (http://webgen.rubyforge.org/) or
Jekyll (http://jekyllrb.com/). It allows mixing pages of different
markup languages and generates a complete static website with a single
command. It is not yet as feature-rich as its contenders but it's easy
to extend and of course it enjoys the general merits stemming from
being written in Scheme.

To get a general idea of how to use Hyde, check out the example
session featured in its documentation.  For a real-world use case,
check out the Chicken Gazette's sources available at
http://bugs.call-cc.org/browser/gazette 

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