Lambda the Ultimate

Yep, it's that time of the year again: It was nine (!) years ago that LtU was born.

As is my wont, I am going to use this opportunity to say a few things in lieu a real life birthday party speech. Those of you with an historical bent may enjoy browsing the full set of birthday posts. Here they are: year one, year two, year three, year five, year six, year seven and year eight.

First, an apology. I am feeling a little guilty posting this, since I didn't post many substantive posts this year. I am still busy doing many things not directly PL related (such as this), and so have little to contribute. I prefer to lurk a bit and let others carry the burden (on this more, in a minute). I posted less home page items and more the discussion group this year, I think.

I find it hard to post as just one of the guys, a regular member of the community, however. Several times I made non-admin remarks about posts that I felt were not on topic for LtU, or - indeed - posted marginal items to the discussion group myself, only to be rebuked by many for misusing my authority or applying policies heavy handedly... So let me take this opportunity to respond from the pulpit... LtU relies on community moderation of posts. This was the mechanism we arrived when the issue of discussion quality came up. All the discussions about this are in the archives. There is no cabal. The solution was simple: members are expected to raise their concerns about problematic posts publicly, so problems and disagreements can be hashed out. Unless I or Anton post a message clearly marked as an "admin" note, which happens fairly rarely, my posts about policy issues have no more weight than those of any other regular member of the community. However, keep in mind that if I am rebuked, many others may conclude that they should refrain from voicing concerns and simply move to other sites. So instead of rebuking me when I voice my opinion - voice yours when messages are problematic (and when messages are particularly useful as well!). If you don't take care of LtU no one will.

So, the "bad news" is that many old-timers didn't carry their burden of policing, and some discussions may have suffered because of this. The "good news" is that this allowed more people to join the discussion. Not only new members (and people are signing up daily) - many people who have been lurking, sometimes for over a year, started posting regularly. This is great! Not only did this add great content, and move the discussion in new directions, it was really nice to see accounts that I presumed were dead come to life. Bet you know what's coming now, right? People who post regularly to the discussion group and think they can contribute to the home page are urged, as always, to let me know so I can make them contributing editors (that's the LtU parlance for members who post to the home page, nothing more; don't be intimidated by the title - you can post as infrequently as you want).

Another nice thing happened this year in terms of members contributing their efforts to the community. A few people volunteered to help deleting spam and spam accounts. I am not sure they want to be identified, but my thanks goes to them. I think we don't need more help on this front for the moment. Still, members should know that new spam accounts are created (and squashed) daily, and that this happens due to the efforts of several members besides the usual suspects.

The LtU "trademark" spread its wings a bit, from they days when LtU was just this blog. This happened without my involvement. Two things worth mentioning come to mind, but let us know if I forgot something important. There is a CiteULike LtU library (originally proposed here), and the a LtU twitter account (see here).

Indeed, it seems many LtU members have flocked to twitter. I am there (@ehud/@biocomputing), but as a late comer I don't have many LtU followers. Others who are better connected may speak up if they want... I am not sure if this a a good thing or a bad thing for LtU, but I guess it was bound to happen. Contributing editors should remember that LtU expects each man to do his duty and post new stuff here first!

Our tenth anniversary is coming up soon. How are we going to celebrate? LtU is a virtual community so maybe a virtual celebration is in order. Maybe we should think about planning a virtual event of some sort or another (guest bloggers, an online conference, or some other crazy idea). Alternatively, we may try to see if we can do something non-virtual... I've always found unconferences to be an appealing idea. Or maybe just LtU beer sessions around the globe... If anyone wants to pick up the glove and organize something, I am sure many here will be delighted.

Thanks again everyone. Let the nine-year long discussion continue!

P.S
I almost forgot... We had a very successful April Fools prank this year...

Found via Wadler's blog: PLATEAU is calling for papers on the HCI side of PL theory, design, and tooling.

Programming languages exist to enable programmers to develop software effectively. But how efficiently programmers can write software depends on the usability of the languages and tools that they develop with. The aim of this workshop is to discuss methods, metrics and techniques for evaluating the usability of languages and language tools. The supposed benefits of such languages and tools cover a large space, including making programs easier to read, write, and maintain; allowing programmers to write more flexible and powerful programs; and restricting programs to make them more safe and secure.

I am just starting Haskell and trying to write an alternative function for returning the last element of a list by using the !! function. I have tried...

mylast xs = xs !! (length [xs] - 1)

but this always returns the head of the list. What am I doing wrong?
TIA,
Chad.

I did say it was very simple...
like the author.

Sun has a new article out that talks about the changes in the upcoming JDK 7 to support dynamic typed languages. Of special note is the new invokedynamic bytecode:

the invokedynamic bytecode instruction enables an implementer of a dynamic language to translate a method invocation into bytecode without having to specify a target type that contains the method. The method specification in this case is a simplified constant pool reference, which specifies only a method name and type descriptor. The descriptor specifies the return type of the call and the type of method arguments.

Full article: New JDK 7 Feature: Support for Dynamically Typed Languages in the Java Virtual Machine

Past discussion on invokedynamic here and JAOO 2005 slides by Gilad Bracha.

I don't want to start a discussion here about the merits of the copyright schemes advocated by the Associated Press, but this may be a nice example of syntax vs. semantics and what semantics are in the real world...

Felten remarks: hNews does include a "rights" field that can be attached to an article, but the rights field uses ccREL, the Creative Commons Rights Expression Language, whose definition states unequivocally that it does not limit users' rights already granted by copyright and can only convey further rights to the user.

Where does ccREL state that? It is, of course, not part of the "statements" of ccREL per se, i.e., the syntax of ccREL clauses. It is part of the definition of ccREL, i.e., the intended semantics of ccREL statements. But clearly, if you think of ccREL (or language, more generally) as just a handy syntax specification, you may end up unconsciously ignoring the intended semantics...

I have no idea if this is actually what happened in this case, of course.

Functional PL :== PL with ability to pass procedures as arguments to other procedures, return procedures as result of other procedures, and store procedures in data structures.

But can we call functional PLs without tail call elimination obligation (TCEO)?
TCEO gives ability to do global jumps, it affects programming style heavily. Also, many helloworldistic programs that come to mind when FP theme arise in conversation employs TCEO.

Maybe it worth to include TCEO in FPL definition?