Mid-August Lisp News
Meetups
Toronto
7 August 2008, A very small gathering of Lisp users at the LinuxCaffe. Abram showed the inner workings of the game Abuse which uses Lisp for almost everything, except the core (which is written in C, this is similar to how Emacs works). An interesting question asked was whether or not the Abuse Lisp dialect supported macros, it seemed that the custom "macros" were all coded in C and thus untouchable. Next, a crazy mod that turns the game into a game of Super Mario was shown.
The disadvantages and misuse of car, cdr, caaaaar, cadaddarr, etc. were also mentioned. The consensus is that once you're using cadr, caddr, what you really want to be doing is creating a structure or object. That way you can access things by a descriptive name. An example of why this is a good idea is given by xmls, an XML parser. It parses XML and turns it into a giant list, with the first element being the element tag name, the second element being a list of element attributes, and the rest of this list being child elements. This can be tedious to navigate through.
Libraries for Scheme were also mentioned. The drawbacks of the various dialects of Scheme are that the specification does not define even the basics of common ways of dealing with libraries. Because of this, when you switch Schemes, you have to re-discover libraries that do what you want. This is an old complaint of course.
Lisp images and program startup costs were discussed in relation to Perl, PHP and Smalltalk. Some Lisps have the ability to dump a memory image and reload that later on. This improves the startup time since libraries are already loaded and not re-loaded or re-compiled. I noted that there doesn't seem to be a culture of image-sharing in the Lisp community as there is in the Smalltalk community. One reason suggested for this is that some Lisps run on 64-bit architectures and others run on 32-bit, which means code needs to re-compiled anyway. Perl and PHP were said to have no way of image dumping and this is particularly problematic for PHP since it seems to rebuild things for each website request. (This may be incorrect or a non-problem)
Finally, I mentioned traits in Smalltalk. Traits are collections of methods that can be used by classes and overridden (or not). Eiffel seems to have something similar, as does Ruby with mixins. Here is the paper that explains the idea more fully[PDF].
comp.lang.lisp
Kenny Tilton, the man
behind Cells
and Theory Y
Algebra, asked
why the special variable *default-pathname-defaults* is
named that way. Pascal Costanza comes up
with an
answer and asks his own question in return,
Do you guys also worry about important problems?
Blogs
Xach's Cool Charts
Xach made some cool charts inspired by Tufte and stream graphs. The first chart shows movie box office data, while the second shows the version control activity of CMUCL and SBCL.
The charts were made using Vecto, a simple vector drawing library for Common Lisp.
cl-cairo2 updates
This is a nice update for cl-cairo2 users. Now cl-cairo2 loads only OS-independent parts of the library, with the OS-dependent parts becoming parts of extension packages.
Lisp Quiz
Lisp Quiz is inspired by Ruby Quiz which was inspired by Perl Quiz of the week. Ruby Quiz and Perl Quiz were weekly programming challenges, and Lisp Quiz hopes to do the same for the Lisp community. The first quiz tackles Minesweeper, having you design an algorithm that wins the game.
Everything Else
LispForum
LispForum, launched on 27 June 2008, is another place for Lisp-related discussion. It is run by Dave Roberts, the blogger who is behind the Finding Lisp blog. They have added a new sub-forum for Lisp Quiz puzzles which are supposed to be similar to the Ruby Quiz puzzles.
What's interesting about LispForum is that it's new (almost 2 months old, only!) and it already has 296 members. There are already 443 posts about Common Lisp, though there don't appear to be many Scheme fans. So we have yet another forum to recommend to newbie Lisp programmers.
