[Chicken-users] Chicken Gazette - Issue 7

[Christian Kellermann]

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--[ Issue 7 ]-------------------------------------- G A Z E T T E
                               brought to you by the Chicken Team


== 0. Introduction

Welcome to issue 7 of the Chicken Gazette, today brought to you by Christian
Kellermann.

== 1. The Hatching Farm - New Eggs & The Egg Repository

Last week has given egg authors a lot to do. The API for using regular
expressions in core chicken has been changed to irregex. This fine library by
Alex Shinn (http://wiki.call-cc.org/users/alex-shinn) has been at work under
the hood for quite a while. The change now incorporates irregex as a regular
unit in chicken-core, which has a severe impact on how eggs have to include the
irregex symbols for usage. Peter Bex (http://wiki.call-cc.org/users/peter-bex)
has written a nice summary on How to use irregex safely & responsibly
(http://www.mail-archive.com/address@hidden/msg12242.html) on
chicken-users.

Due to this change one could see a spike in eggs failing
as the API change has been comitted. Mario Goulart
(http://wiki.call-cc.org/users/mario-domenech-goulart), Ivan Raikov
(http://wiki.call-cc.org/users/ivan-raikov) and all the other egg authors
converted most of the failing eggs to the new API. At the time of writing this
27 eggs (http://tests.call-cc.org/2010/10/11/salmonella-report/) still need
your help! Please check the eggs you maintain whether they need care.

Peter also has added http-proxy support to http-client
(http://wiki.call-cc.org/eggref/4/http-client) and would appreciate testing and
feedback on it.

Another Peter, Peter Lane (http://wiki.call-cc.org/users/peter-lane)
added a wrapper for simple vector machines called libsvm
(http://wiki.call-cc.org/eggref/4/libsvm) to our egg pool. He also released
another version of leptonica (http://wiki.call-cc.org/eggref/4/leptonica).
Thanks Peter(s)!

== 2. The Core - Bleeding Edge Development

First of all as of October 6th chicken's development branch got a new snapshot:
4.6.3. Thanks to all the contributers that made this possible!

>From the NEWS file:

  * the `regex' library unit has been removed and is separately available as an 
    extension which should be fully backwards- compatible                       
  * `irregex' is now a core library unit and replaces the `regex' API           
  * `-frwapv' has been added to the default C compiler options                  
  * configuration-header fix for BSD systems (thanks to Peter Bex and Christian 
    Kellermann (http://wiki.call-cc.org/users/christian-kellermann))            
  * added support for `pointer-vectors' (unit `lolevel'): make-pointer-vector   
    pointer-vector? pointer-vector-length pointer-vector-ref                    
    pointer-vector-set!                                                         
  * added new foreign type `poiner-vector' which maps to `void **'              
  * new "implicit renaming" macro facility contributed by Peter Bex (see        
    `ir-macro-transformer')                                                     
  * the warning shown when unimported identifiers are used in                   
    compiled modules now also shows the name of the procedure where             
    the identifier is referenced (suggested by Alaric Snell-Pym                 
    (http://wiki.call-cc.org/users/alaric-blagrave-snellpym))                   
  * the deprecated `random-seed' function has been removed                      
  * parameters are now settable and can be modified using `set!' (SRFI-17)      
  * the impementation of overflow-detection for arithmetic operations on        
    fixnums have been replaced and now allow using the full 63-bit range of     
    fixnums on 64-bit systems                                                   
  * fixed serious inlining-bug (thanks to Sven Hartrumpf                        
    (http://wiki.call-cc.org/users/sven-hartrumpf))                             

The curious and daring adventurers are invited to try and test this developer
release as hard as they can.

== 3. Chicken Talk

This week the chicken-user mailing list has been talking about the necessary
steps for egg authors to fix their eggs with the new irregex changes.

Daishi Kato (http://wiki.call-cc.org/users/daishi-kato)
raised the question on how to handle http multipart/form-data
(http://www.mail-archive.com/address@hidden/msg12203.html) which is
still an open path that needs exploring.

Peter asked about the right way to install data files along eggs
(http://www.mail-archive.com/address@hidden/msg12208.html).

Mario found some inconsistencies in the docs regarding require semantics
(http://www.mail-archive.com/address@hidden/msg12227.html)

== 4. Omelette Recipes - Tips and Tricks

Today I want to direct your attention to a small egg that may help you in
writing nice visualisations: ezxdisp (http://wiki.call-cc.org/egg/ezxdisp).
This wraps the small X11 library (http://morihit.net/ezxdisp/) written by
n-sibata and Morihiko Tamai. Ezxdisp provides you with easy procedures to draw
basic 2d and 3d graphics on your X11 display. On Windows the native API is
used.

>From a small hello world example

    (define ezx (ezx-init 100 100 "Hello, ezxdisp"))
    (ezx-set-background ezx (make-ezx-color 1 1 1))
    (ezx-fillcircle-2d ezx 50 50 25 (make-ezx-color 1 0 0))
    (ezx-redraw ezx)
    
    (let loop ()
      (let-values (((b _ _) (ezx-pushbutton ezx)))
        (loop)))
    
    (ezx-quit ezx)

up to a 3d clock
(https://anonymous:@code.call-cc.org/svn/chicken-eggs/release/4/ezxdisp/trunk/3d_clock.scm)
all is possible.

This allows small and fast coding of processing (http://processing.org)
like visualisations such as drawing Wolfram's automata
(http://pestilenz.org/~ckeen/wolfram/automata.scm).

Have fun drawing!

== 5. About the Chicken Gazette

The Gazette is produced weekly by a volunteer from the Chicken community.
The latest issue can be found at http://gazette.call-cc.org or you can
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If you'd like to write an issue, check out the instructions
(http://bugs.call-cc.org/browser/gazette/README.txt) and come and find us in
#chicken on Freenode!

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