The Weekly Squeak

Torsten Bergmann has an interesting post which introduces JavaConnect, a project by Johan Brichau, a postdoctoral researcher at the Université catholique de Louvain. JavaConnect is a library (developed using Visualworks Smalltalk and released under the MIT licence) that allows a seamless interaction between Smalltalk and Java. Johan describes it as allowing a Smalltalk application to “access any Java object and send messages to it, just as if it were a Smalltalk object. Its implementation relies on a connection between the Smalltalk environment and a standard Java VM environment using Visualworks’ DLLCC and Java’s JNI. The Java application thus executes on a regular Java VM and the Smalltalk application executes on the regular Smalltalk VM.”

Joachim Geidel posted a comment giving a detailed comparison of JavaConnect to JNIPort, a similar tool developed by Chris Uppal for Dolphin Smalltalk, and ported by to VisualWorks by Joachim, a consultant for blueCarat Consulting GmbH. JNIPort (available under a bespoke, liberal licence) invokes a Java VM using the Invocation Interface functions of the Java Native Interface (JNI). It can automatically generate wrapper classes for Java classes.

Joachim and Johan developed the two projects in parallel, and have discussed whether they could merge in the future, although there are a number of differences in the designs at present. In particular, Joachim believes that JNIPort as currently implemented could be more readily ported to Squeak.

Stéphane Ducasse maintains a great list of free Smalltalk books including online pdfs of many out-of-print books.

These books span over twenty years of Smalltalk development, and includes great resources such as Smalltalk-80: The Language and its Implementation (the “Blue Book”), Smalltalk with Style(pdf), and more recent classics such as Squeak by Example (written by Stéphane Ducasse along with Andrew P. Black, Oscar Nierstrasz and Damien Pollet).

This is a great resource that is of use to beginners and to more experienced programmers wanting to understand more of the philosophy and design decisions behind Smalltalk and Squeak.

Links and reviews of many other (non-free!) books can be found at the Squeak wiki, John M McIntosh’s site, and Squeakland has a reading list prepared by Alan Kay for those who want to learn more about the ideas and philosophies that influenced the creation of Squeak.

If you know of other books and online resources that should be listed here, please let us know!

[Please note the URL has been updated to address David's comment below. The original URL was an older page with fewer books available.]

Randal L. Schwartz just announced that he will be giving a 3 hour tour of Seaside at OSCON 2008. We are very proud to have Randal on the Squeak Foundation Board. We are looking forward to more of his “Year of Smalltalk“.

[Edit: corrected spelling]

The following was posted to the Squeak-Dev Mailing list by Markus Denker. The quote speaks for itself and it does give one pause to consider the implications to our community. It also strikes me as relevant to a lot of other development communities too. Great ideas are still very powerful and inspiring, but the idea alone is still seen as only half the process. We all know that there is a lot of very interesting problems that arise while we transform our ideas into working code. We also know that it is much easier to build onto a working system, or take what we learned from the process of building a working system to the next generation. While the idea itself can be seen as a great accomplishment, the realization of the idea by itself confers even greater benefits to the community. What projects have you left undone? What’s the difference?

“One of the sad memories of my life is a visit to the celebrated mathematician and inventor, Mr Babbage. He was far advanced in age, but his mind was still as vigorous as ever. He took me through his work-rooms. In the first room I saw parts of the original Calculating Machine, which had been shown in an incomplete state many years before and had even been put to some use. I asked him about its present form.
‘I have not finished it because in working at it I came on the idea of my Analytical Machine, which would do all that it was capable of doing and much more. Indeed, the idea was so much simpler that it would have taken more work to complete the Calculating Machine than to design and construct the other in its entirety, so I turned my attention to the Analytical Machine.’”

“After a few minutes’ talk, we went into the next work-room, where he showed and explained to me the working of the elements of the Analytical Machine. I asked if I could see it. ‘I have never completed it,’ he said, ‘because I hit upon an idea of doing the same thing by a different and far more effective method, and this rendered it useless to proceed on the old lines.’ Then we went into the third room. There lay scattered bits of mechanism, but I saw no trace of any working machine. Very cautiously I approached the subject, and received the dreaded answer, ‘It is not constructed yet, but I am working on it, and it will take less time to construct it altogether than it would have token to complete the Analytical Machine from the stage in which I left it.’ I took leave of the old man with a heavy heart.”

– Lord Moulton
–
Marcus Denker http://www.iam.unibe.ch/~denker

Hi all Squeakers!

Ok, the Squeak Foundation Board Election 2008 ended 19 minutes ago -
promptly at 18.00 UTC, 8 March.

For this year we had 437 authorized voters of which 178 voted, that is
slightly more than 40% voting - a bit disappointing IMHO since we had
157 voting of 347 last year which gives above 45%.
On the other hand 178 is more than 157, so we had more voters and thus a
growing community, which of course is the most important aspect!

And without further ado I bring you the board for the following year
starting from NOW. The order reflects the ranking from the election:

1. Dan Ingalls
2. Craig Latta
3. Bert Freudenberg
4. Yoshiki Ohshima
5. Tim Rowledge
6. Randal L. Schwartz
7. Igor Stasenko

Read the rest of this entry »

Andrés 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.

Great video of the Waveplace XO Laptop Day.

Well I couldn’t resist. Aaron E. Walsh sent out an invitation to the Squeak - Croquet communities for an ad-hoc Immersive Education Meeting. The Boston Digital Summit held in January covered the Education Grid, this meeting was a chance to review this information for those that were not able to make it to the summit.

Second Life was quite an experience. I had to sign up and go through some training, figure out how to get to Sun’s virtual auditorium and sit down. It was quite amusing to see some people show up on stage and not know how to sit down either, so I didn’t feel so bad. Maybe I should have spent more time in the training.

Aaron, reviewed the details of the Education Grid. The Grid is an education content virtual repository focused on interoperability, standards, and quality educational content. The goal is to provide standards that allow content to be developed to operate in different virtual worlds. These standards must be open source to ensure that content can be made freely available.

Content is just a piece of the puzzle in education. Educators also need tools to be able to evaluate the progress of students. There are a number of general tools that should be developed and made available in a consistent way for each offering. Aaron mentioned, “While it is possible to record everything that happens in a virtual world there is no way an educator could watch everything a student did in an activity that might take 2 hours.” Tools that allow educators to evaluate raw data, to assess progress and to track grades, and to create content are essential.

Quality content will be assured by having a Peer Review of offerings before the become part of the grid. The peers will be selected from the community and people with special expertise will be sought to make sure that the education goals are met, the content is accurate, standards are followed, and licensing is compatible to be a part of the grid.

Licensing and interoperability were the major concerns once Aaron opened the floor to questions. Ownership of the content was also discussed. Aaron mentioned that a not-for-profit organization would own the grid, but that the grid would be virtual and would be hosted by multiple organizations. I’m not sure there was a full answer about the ownership of the content. I would have suggested that copyright stay with the author or developing organization, and that the grid would receive unlimited rights to distribute the content, much in the same way were are trying to organize the Squeak community.

Well I ran out of time but Aaron did a very nice job of wrapping it up just a few minutes over. Thank you! The concept is really a terrific idea. I hope that our communities will join together and support developing freely available virtual world educational materials. Aaron mentioned that other meetings will be held in Croquet, I look forward to that. I hope to see you there. Hopefully that meeting will be just as well attended as the SL meeting.

Smalltalk positions around the world! Interested in a Smalltalk Job? Ready to see the world? Check out Noury Bouraqadi’s Smalltalk Jobs and Internship page.

Dr. Bouraqadi just posted 3 new Jobs in Paris France, for French Speakers.