Hashing in Smalltalk

25 February, 2008

Hashing in SmalltalkAndrés Valloud has just published “Hashing in Smalltalk: Theory and Practice” on Lulu. He describes the book as providing “a strong foundation for hashing, hash functions, and their application in the context of software development. The first part develops hashing and hash functions from first principles. The behavior characteristics required of hash functions are examined in detail. A thorough description of how hash functions are constructed follows, complete with a rich survey of existing hash functions. But often times existing hash functions are inappropriate for the task at hand. To address this problem, the second part shows how to build novel hash functions that are both efficient and of very high quality for many of the types of data that occur in practice.”

The book compares algorithms and implementations of hashing across the main Smalltalks (Squeak, Dolphin, Visual Works and VisualAge), as well as other languages including C, C++, C#, Java, OCaml and ML. It’s available for $40/€32.20/£22.04 .

Andrés has also posted a great illustration of the dangers of the use of inappropriate hashing functions.

Randal Schwartz and Leo

Don’t miss this fun new video from Randal Schwartz and Leo about Squeak, EToys and OLPC.  Randal builds a very nice car demo.

Legal Books

The Software Freedom Law Center just released a terrific readable guide to Free Open Source Software Legal Issues.

A Legal Issues Primer for Open Source and Free Software Projects (html / pdf)

Our thanks to the SFLC and all the terrific people there for their tireless efforts to support open source software communities!

Brought to you by ESUG!

23 January, 2008

ESUGWelcome

The European Smalltalk Users Group – ESUG has generously agreed to support international smalltalk presentations.

From Prof. Stéphane DUCASSE :

Hi all

as announced at Lugano ESUG is putting in place new action to promote the use of smalltalk http://www.esug.org/promotionactions/publicationpromotion/

PublicationPromotion
ESUG offers 150 Euros for each international conference paper whose concepts involves an implementation in Smalltalk

Rules
• After notification of acceptance, one of the authors sends to the ESUG board the article, a CV, and a brief explanation of how Smalltalk was used
• In case the ESUG board decides to support the promotion, the author has to send to ESUG after the camera-ready deadline a PDF of the article, where ESUG is referenced in the acknowledgment section, including a link to esug.org
• During the presentation at the conference, the author must mention ESUG support
• After the presentation at the conference the author sends to ESUG a PDF version of the slides, where there is a visible reference to ESUG (e.g. theESUG Logo). ESUG will put the slides on the ESUG website
• The author can then trigger the payment by sending an e-Mail to the ESUG board
• A maximum of 3 supported articles per year per institution is allowed

Prof. Stéphane DUCASSE [ | ]
http://stephane.ducasse.free.fr

Open Source Smalltalks: http://www.squeak.org, http://www.gnu.org/software/smalltalk/smalltalk.html
Free books for Universities at http://www.esug.org/sponsoring/promotionProgram.html
Online Free Books at http://stephane.ducasse.free.fr/FreeBooks.html

Argentina Smalltalk 2007

From Hernan Wilkinson:

Hi,

I just wanted to let you know that the Smalltalks 2007 presentations are available at https://www.dc.uba.ar/events/smalltalks/2007/presentaciones
Most of them are in English although not all.
You can look some pictures at http://picasaweb.google.com/smalltalks2007 and http://picasaweb.google.com/WeybridgeWay/1erCongresoArgentinoDeSmalltalk

I wanted to give a public “Thanks” to ESUG for their support (DVD, book, ideas, etc), Viewpoints, Dan Ingalls, James Robertson, John Sarkela and Bruce Badger for the videos. Stef and Noury sent me something to read but finally I did not have the time to do it (sorry). Also, to all the sponsors that helped us with the conference.

Below are some comments we got in the Argentine Smalltalk lists (first in Spanish and then in English, translated by Andres Valloud).
It is very hard for me to find the right words to express how happy we are with the outcome of the conference, not only for the amount of people that came but also for their kindness and technical level of the presentations. Thanks to all.

Hernan
Read the rest of this entry »

Semaphore

The Little Book of Semaphores” by Allen B. Downey has been highly recommended on Squeak-Dev. This is a terrific source for understanding semaphores and learning how to apply them. The book includes puzzles and examples. Visit the Unisex Bathroom or help the Baboons crossing a canyon.