Just showing up at Coupa Cafe and connecting to their wifi now automatically does a Facebook checkin there. Good idea for Coupa. And when this spreads to embaressing locations it'll make your Facebook feed a lot more interesting, so good for Facebook too!
Seriously, I think it only checks you in if you've already accepted thier TOS once. So the loss of privacy is probably in the 'one more step' sweet spot. The frog is staying in the pot.
I've had a new blog over at Posterous for a while. Posterous was designed to be a miniblog platform - perfect for tiny posts. The thing is, I like the visual design of it better that what I can get here with Blogspot, so I'd like to make it my primary blog. Unfortunately, Google gives no respect to it yet. We'll see. Here it is: http://herdrick.posterous.com/.
I'm using the Disqus commenting system now. I've commented on other blogs that use Disqus and found it excellent. Time to set it up here.
Years ago I often read and posted at the Joel on Software forum. In mid-2003 someone started a thread to complain that the best days of software development were in the 1980s and to ask the forum's opinion about his chances in writing some successful software on his own. Of course, out of the woodwork came a solid crop of Eeyores, right on schedule. What is it about complaints and pessimism that attract such a following? Remarkably, Eric Sink - whom I admire - joined right in with them. But I guess if you are fixated on desktop software, today is boring and barren. Just like mainframe programming wasn't any fun any more in the 1980s...
Anyway, I had to object. So I posted:
No. TODAY is the best of times, and software is the best of businesses. You forget that back then there was no way to get your product to customers except through the computer stores at the local mall. The internet is the most open sales channel imaginable, linking producer of IP to customer directly. Those old timers had it hard.
No matter how endless the possibilities and bountiful the opportunities, there will always be those whose covetous eyes are drawn to the crowded streets of exploited opportunities instead of the open blue yonder of infinite possibilities. If this is you, please, start exercising the creative parts of your brain, build some castles in the sky, and stop underestimating your own potential to build something new.
I like the newest Y Combinator startup, Heysan. They offer a chunk of HTML that you paste into your blog or MySpace page or whatever. The HTML is a slideshow, displaying the pics you email to an address they give you when you sign up. It's very simple.
You know that delighted feeling you get when you find a 'hidden' feature in a product? Heysan gave me one of those. I only had a single pic on my phone to send, and since a slideshow of one image isn't really a slideshow, I needed another way to get photos into my account. So I tried emailed some from my desktop, and it just worked. Well done, Heysaners.
I'd like to be able to turn off the pixie dust effect. I'm sure this is possible and I'll read all about it when they have an FAQ/Help page written.
If you can't see the slideshow at the top of this blog, please leave a comment.
Since Google seems to be having a hard time finding it the right definition, I'd like to point out for the record that in Scheme, atom? should be defined so:
(define atom?
(lambda (x)
(and (not (pair? x)) (not (null? x)))))
Upon emerging from the worst of my head-cold chest-cold fever, I realized: association lists work fine for any arbitrary key/value pairs. A very obvious thing I suppose, but something had been throwing me off when I was thinking of alists this morning. When you cons the key onto the value, but the value is a list, then the resulting alist entry isn't a dotted pair, it's just a plain old list. But who cares? Functionally it's identical. It may as well be a dotted pair. Look:
(a . (1 2 3))
(a 1 2 3))
Are the car and cdr of this any different? No.
Obvious, yes, but I had a fever! I was lucky to be thinking at all. Get off my case!
Perhaps not swamped, but I'm seriously bogged down right now with a lot of things that aren't exactly what I'm trying to get done, but really need to be done anyway. It's Yak shaving.
Another web service has made my varsity team. Google Transit tells you how and when to take the bus to wherever you want to go. It's a must if you live in King county (i.e. metro Seattle) and commute to a high-density area (the U-District, downtown, Belltown, SODO, downtown Bellevue, etc). I use it daily. Imagine Google Maps driving directions with discrete choices leave time choices and you pretty much have it.
It only really has two problems: buses often run late (so the times can't be taken too seriously), and it's probably not available in your town. But if you're one the lucky people in one of these places, try it: Burbank (Burbank Bus), Orange County (OCTA), Tampa (HART), Honolulu (TheBus), Duluth (Duluth Transit), Eugene (Lane Transit District), Portland (TriMet), Pittsburgh (Port Authority), and of course, Seattle (King County Metro).
Speaking of new directions in life, last night at the SeaFunc meeting I was talking with an interesting fellow and somehow or other the topic of major life changes came up. I quoted a person in Michael Lewis' nonfiction Wall Street memoir, Liar's Poker. (That was a heck of a book - you should read it - and it had an big impact on me. Speaking of that book, and this one, I need to do a post about investment banking, the study of Economics, the Pacific Northwest, word of mouth and clouds of personal connections someday. Remind me.) I think it was his mentor in London, who, when Lewis told him he was leaving his carreer in finance just when it was about to make him very rich, said something to the effect of, "Good for you. These major life changes are always the right decision." Now, a programmer going back to school to study Computer Science isn't exactly like closing the shop, selling the house, buying a ticket to the west coast and giving them the stand up routine in L.A., and it wasn't much of a change compared to my usual life modification, but this time I wasn't in some kind of desperate or dead-end situation. So I think it counts as a significant change.
Didn't think I had time, blah blah blah, you've heard it all before.
Before coming to this conference I hadn't realized how much the Functional Programming community is dominated by Haskell people. Most of the presenations are very Haskell-y even though in theory much of the work should be universal.
Although the Scheme people occasionally point out to a presenter that his work sure looks like something the Scheme people figured out fifteen years ago, the two camps seem to get along fine most of the time. Wait'll the coffee runs low, though.
I really should apologize to my readers for the content of my posts on the presentations at the ICFP. Most of what I am saying about these have to do with my own level of knowledge about the subject (ranging from very minimal to completely innocent) and extent to which it piqued my interest, instead of the content of the talk. This is the way it has to be, as I am, with some exceptions, not sufficiently knowledgeable about the field to speak with authority about the talks - in fact I generally can't even provide a synopsis.
If you want to know about one of the presentations you'll need to find other bloggers, or better yet, read the paper. At least the abstract. But than since such papers are almost always available on the web, I have to ask: why are you reading this? Probably you are one of my regular readers (hi Mom!). Or you wrote the paper and are interested in what the community thinks of it (hi Jacob!). It's to the second group that my apology is directed: I'm sorry. I really don't know. You may as well ask the congressional page what he thinks of the Constitutional implications of a bill being debated. (I originally had that "ask the dog about the craftsmanship of a Persian rug he just soiled" but this is a family blog and a cheap dog poop joke just won't do now, will it?)
But if, like me, your understanding of most of the papers is limited, then maybe you are reading this blog to help you to decide if you should go to next year's ICFP. The answer is yes. Go, even if you must pay your own pay like I did. You meet really interesting people. I've met the authors of my favorite computer book of all time for example (one of them, Dan Friedman, and his co-author of another book, Robert Byrd, are right now sitting directly to my right, huddled over a cons cell diagram and some Scheme code scibbled on some hotel stationary trying to puzzle something out. Cool, eh?) You get to talk to interesting people and get a real feel about what the work of an academic is like (at least the research part). You get an idea of where the field is going, who is considered to be doing the most interesting work, and most of all, what parts of the field have attracted the most interesting and enthusiastic people and how to participate in those parts. I can tell you that I'm much more seriously thinking of grad school now than I was when I arrived. I want to understand more of these papers.
I'm not especially interested in concurrency issues (read that: I'm not sufficiently knowledgeable in the field to be interested). They tend to be difficult, non-hackable problems. That is, you can't just start hacking away on the problem to see what works. You have to prove that your solution works; no amount of testing (much less a quick try through a few edge cases) can prove that it will work. That said, I'm all for people coming up with abstractions or frameworks that ease this problem for those of us who would rather not think about these problems so much. Hats off to them!
Everything before lunch today (Tuesday, the second day of the official conference, my third day day here since I attended this pre-conference Scheme workshop) is on the topic of concurrency so I'm not exactly on the edge of my seat. I wonder if I can catch a nap somehow...
Nevertheless I was interested by the first talk, by Marc Shapiro on using Rely-Guarantee analysis to prove correctness of concurrent programs. If I understand what he is doing, his work shows a new way to divide the concurrency issues of a given program into smaller pieces, each of which may be divided into smaller pieces using the same technique, until the pieces are small enough that the set of all the things that the pieces rely upon are guaranteed by the pieces. If you can do this, your program is proven to be safe with concurrency. I need to read the paper, except it looks like only the abstract is present in the Proceedings of the conference.
Surely everyone envies Perl's CPAN. Other languages either already have such a system (like Ruby Gems or Common Lisp's asdf-install) or are building one.
So one of the happy warriors who hack PLTScheme, Jacob Matthews, has come up with a system of his own, Planet. It sounds good. I really don't know much about it but at least one can be heartened by his choice of models, CPAN and Debian's apt-get.
It has some nice features:
They enforce standards on the numbering of versions. If you release a version that breaks users of your previous version, you must call it by a new major number (5.0, 6.0, etc.)
They have integrated Dr. Scheme with this so that you can visually see what functions came from what packages, using the arrow pointing thing that Dr. Scheme uses to show you your stack trace when your code crashes. (Wait, is this just part of the packaging system? I'm not sure that Planet added this. In any case, it's a good thing for Scheme.)
Of course the real difference between this and CPAN is that CPAN has 2 gigabyes of perl source made up of who knows how many gazillions of modules. Planet has 115 packages (or modules, I don't know about Scheme packaging).
Given the trouble I've had getting Common Lisp's asdf-install configured properly on my Windows machine, I am hopeful about the prospect of something better in the Scheme world.
Technorati: scheme, icfp, lisp, pltscheme, drscheme, planet, packagerepositories
Ray Rischpater gave an gratifying talk on what his company, RocketMobile Phone has done with Scheme on the mobile phone. They've done it with a port of TinyScheme.
It sounds like they wrote their own browser so that they can get access to things like the address book, the list of recent phone calls, etc. Probably GPS data too. They do this by serving WML-like pages to the browser that include Scheme between script tags. I'm interested in knowing why they chose the browser route. They were building their own client to interact with thier own server... is the browser model superior even for a single application, single server situation? I suppose a major factor was that they already had server-side infrastructure ready to go, including programmers that are accustomed to that model. And who knows, maybe they are reserving the option to dominate the wireless browser market for the glory of Scheme!
Question: are they sending WML to their browser when not sending blocks? It would seem so.
(Technorati Tags: icfp, scheme, lisp, wireless, rocketmobile, tinyscheme)
So far this was the best session for me here at the ICFP. We've been hearing a lot about using continuations for keeping state in web applications. This was a good, non overreaching presentation on the subject. It was something of a revelation for me. I was previously under the impression that if you choose the continuation-passing method of preserving state, then you forsake all others. Putting data in cookies, keeping session data in the database (with session id in URLs or in a session variable), putting data directly in session variables... I had thought that this new statefulness required you to kick these to the curb. But it turns out that continuation passing is not jealous. There's no reason not to use them for some of the state in your application and whatever other method for other parts of your state. This is great. Basically you keep using the older methods of state as long as they are working fine for you. It's only when the state becomes problematic (Jay implies that this especially comes up when the user has multiple views of the same data open at once) that you turn to the continuations. Kudos to Jay for being pragmatic about this. Jay's paper (with Shiriram Krishnamurthi) and presentation was based on the the production code they shipped for the PLT Web Server to do these continuations.
Great talk.
(Technorati Tags: icfp, scheme, lisp, continuations, pltwebserver, web)
SeaFunc's own Guillaume Germain presented on Termite Scheme. This is his implementation of the interesting and useful principles of Erlang in Scheme. As I know nearly nothing of Erlang, I appreciated his overview of what exactly it's principles are. Those include : "Every process has a mailbox, the only way to talk to it is send it a message." "Sending a message won't block." "Receiving a message might."
Interesting talk. It was good to talk to Guillaume again, too.
(Technorati Tags: icfp, scheme, lisp, erlang, termitescheme)
Some very interesting stuff so far. William Byrd - coauthor of The Reasoned Schemer (along with Dan Friedman, who is sitting behind and to the right of me which is pretty damn cool. Dan and Mattias Fellesen co-wrote The Little Schemer, which is probably my favorite book ever. Mattias sat right next to me earlier. There's the advantage of a working with a language that hasn't achieved mass popularity - beginners like me are have access to the leading people. That the leading people of your language are a big chunk of the leading people in the field of Computer Science is a good indication that you are working with the right language.) - gave a talk on his and Dan Friedman's creation, miniKanren, which apparently is a more or less an implementation, in Scheme, of an imaginary language described in that book. It's for logic programming - interesting. He lost me several times - I need to read the paper. And learn more about logic programming generally. Byrd is a very clear speaker. It would seem he's given the talk before, based on his polished delivery. If not he's someone a conference-goer really appreciates: a speaker who rehearses a lot.
(Technorati Tags: icfp, scheme, lisp, minikanren, logicprogramming)
Hello, readers. I've been mulling the advantages of moving my blog to an automated and hosted option for a little while now. I think now's the time. Now if I can figure out how to add my old blog's posts here with the proper dates...
My old blog is www.herdrick.com
Time to stop noodling around on the new guitar and start playing. I just got back from my first lesson ($40 per hour! It better be good.) I'm looking forward to plenty of hard but rewarding work. A lot like the other learning going on in my life right now.
You know it was a good party when you find mysterious things like this the next morning:
Did you hear a booming sound or was that just in my head? The TechCrunch party last night was good and there were some signs that technology optimism is back.
Demos and evangelizing by the sponsors, Redfin (who paid for the hefeweizen and pizza I'm told), TripHub and Farecast, were available on the corners and edges of the rooms. I like TripHub; it's sort of an Evite for trips with lots of extra features. I wonder if it would work for planning mountaineering expeditions? Farecast looked more like an economics research project than something I would use. The idea is that is uses historical data to figure out when airfares go up and down for particular routes on particular days, and then recommends when to buy tickets. I'd think that the cyclical trends this thing tracks would be overwhelmed by changes in fuel prices and structural changes in the industry. The airline business is known for major changes which would make previous data pretty useless. In any case I'm not waiting a week to buy airline tickets because some software is confident that the price will drop $20. Sounds like a hassle.
Quite a few conversations about interesting startup ideas were happening and - funny thing - the founders were admirably keen to talk in detail about what they are working on and why it's good. That was unusual - getting people to tell you what they are building can be impossible. Winter Founders Program investee Chris Smoak was there, plotting his move to Boston and mulling over the virtues of other towns, like Portland and Pittsburgh. I met up with John Wulff whom I had previously met at the Seattle Ruby users group, and Ruby on Rails podcaster Geoffrey Grosenbach and Tom Lianza also from Seattle Ruby. Tom will soon launch his startup, Wishlisting which sounds like a useful service. The founders of this hotornot inspired site drove down from Vancouver and seemed to think it was worthwhile. UPDATE: Thanks to TechCrunch and Jay and Silent Rob for links...
A good party - and the abundant free beer and pizza didn't hurt.
I'm looking for my friend Erik Lickerman who has recently moved to Cambridge, (Boston) dropping his email address and telephone number. So if you see this Erik, email me. Hester and I are looking for you.
In reading the excellent book, The Little Schemer (see blog posting below) and writing the code for the exercises, I've come across something in Chapter 6 that is puzzling me. It appears that the book's code for numbered? is wrong. (Yes, I know it's not. Just stick with me while I try to figure out what I'm missing.) Here it is:
(define numbered?
(lambda (aexp)
(cond
((atom? aexp) (number? aexp))
((eq? (car (cdr aexp)) '+) (and (numbered? (car aexp)) (numbered? (car (cdr (cdr aexp))))))
((eq? (car (cdr aexp)) 'X) (and (numbered? (car aexp)) (numbered? (car (cdr (cdr aexp))))))
((eq? (car (cdr aexp)) '^) (and (numbered? (car aexp)) (numbered? (car (cdr (cdr aexp)))))))))
> (numbered? '(1 + 2))
true
> (numbered? '(1 + a))
false
> (numbered? '((1 X 2) + 3))
true
> (numbered? '(1 + 2 X (3 + 4) ^ 5))
true
> (numbered? '(1 + 2 X (3 + 4) ^ a))
true
> (numbered? '(1 + 2 X (3 + 4) ^ a + + ))
true
> (numbered? '(+ 1 + 2))
(numbered? '(+ 1 + 2) aren't allowed. OK, but what about (numbered? '(1 + 2 X (3 + 4) ^ a))? Well, here's the definition of an arithmetic expression from the book: "For the purpose of this chapter, an arithmetic expression is either an atom (including numbers) or two arithmetic expressions combined by +, X or ^". Now, I thought that would include something like (1 + 2 + 3), since 2 + 3 is an arithmetic expression, and 1 is an arithmetic expression. Since this book is all about recursion and defining things recursively, my mind sort of skipped over the fact that although 1 is an arithmetic expression, 1 + is not. So (for the purpose of this chapter) (1 + 2 + 3) isn't an arithmetic expression.numbered? is just the most egregious of those so far, really most of the code in the book doesn't handle bad input. Yes, I completely realize that this is meant to be a learning experience about recursion, lambda calculus and so forth, and not about practical stuff like error handling, and I'm glad of it. The problem is that it's hard for me to get myself completely unwrapped from my practical experience. My brain has a hard time not coming up with code that tries to deal with this.numbered?, which works for a more broad definition of arithmetic expressions:
(define numbered?
(lambda (aexp)
(cond
( (number? (car aexp)) (or (null? (cdr aexp)) (and (operator? (car (cdr aexp))) (numbered? (cdr aexp) ))))
( (operator? (car aexp)) (and (or (number? (car (cdr aexp))) (not (atom? (car (cdr aexp))))) (numbered? (cdr aexp))))
( (not (atom? (car aexp))) (and (or (null? (cdr aexp)) (operator? (car (cdr aexp)))) (numbered? (car aexp)) (numbered? (cdr aexp))))
( else (write "else") #f))))
(define operator?
(lambda (op)
(cond
((eq? op '+) #t)
((eq? op 'X) #t)
((eq? op '^) #t)
(else #f))))
(define numbered-simplified?
(lambda (aexp)
(cond
((atom? aexp) (number? aexp))
(else (and (numbered-simplified? (car aexp)) (numbered-simplified? (car (cdr (cdr aexp)))))))))
The Little Schemer was first published (then called "The Little LISPer") over two decades ago, it uses an dialect of a somewhat obscure programming language that's been around since 1958, and it's the best computer book I've ever read. It's the best textbook I've ever read. In fact, it's the best book I've ever read to learn something. Maybe it's just the best book. Why? Look at the first page of text (courtesy Amazon):
Where's the text? Where's the explanation of what I'm supposed to learn? Where's the material? Well, it there, but it's just questions and answers. You read a question and you try to answer it. You probably know this as the Socratic method of teaching, or it would be called that if there were a teacher in the flesh asking the questions. You would think that such a style of learning would rely upon the teacher carefully monitoring the student's understanding and tailoring the questions accordingly. But I guess not. Or that is, I guess you don't need to customize the questions, you just need to get the questions exactly right. They did.
(Even if this book weren't socratic, I'd be in my top ten of computer books just for jumping into the subject right off the bat instead of starting with fifty pages of the usual filler followed by a "gentle" introduction to the topic at hand. If I had a dollar for every book I own that has: "Chapter One: The History of Java" and "Chapter Two: Why Should I learn Java?" and "Chapter Three: Java and the World Wide Web" I could save myself the time of selling them on Amazon. Though I could make, in many cases, as much as double that.)
The really great thing about this book is that actually the material mostly isn't there, not in print. The most important part of the "read a question, try to answer" cycle is "figure out what the writers wanted you to learn from it". For the best questions, you don't figure out all the intent until several questions later. Or maybe even several chapters later, I don't know yet. I'll keep you posted.
So are there any other "socratic" books? Yes. The authors of The Little Schemer (Daniel P. Friedman and Matthias Felleisen) later wrote a similarly styled book about Java (and though I haven't read it, I know Java very well, and I'm pretty sure that what the reader learns is far inferior in that book). This book in turn collected an imitator (I mean no disrespect) directed at teaching Ruby. Only a few chapters of the Ruby book have been written, but on the plus side, they are freely available. Shouldn't there be books written in this style in other subjects? There must be, right?
In raving about socratic books, I have left something out. I implied above that the subject matter of the book is a drag on it's greatness, that the book is good in despite that it's a Lisp book. And I would be pretty impressed with such a book no matter what the topic. But in fact I am working my way through the book entirely *because* it's teaching me Lisp (in this case the Scheme dialect of Lisp), or using Lisp to teach me how to program in the Lisp style. And Lisp is good.
Want a Google-esque logo? The fun people at GoogleFor.com have it covered for you. You can make a logo with any arbitrary text and they throw in a branded skin on Google while they are at it.
You can get sort of 2003-vintage web startup logo from the same folks: 
Downside: it looks like a bag of ugly. Also, it's in .bmp format. I guess this must have been the first version, which gives the little "beta" stamped on each logo extra meaning. Really you can do better than this in a few minutes with MS Paint.
My excellent friend from high school, Robert Dymond, has the oldest blog I've ever heard of. I remember finding a link to it in my email way back in 1998, and thinking, this is entertaining, but why does Dymond *want* to entertain the world with what he been doing lately?
He's still ahead of the curve, as he has a pretty detailed calendar of the next few months of his life online in the public eye. He's blogging the future, you might say. And anyone can edit it, so maybe it's more like he has a wiki life.
