Experiences with Clipper

While I was away in Japan, Caltrain and the other Bay-Area transit agencies teamed up to introduce the Translink Clipper payment system. I was excited at the prospect of an easy-to-use IC-card payment system like the Suica system I enjoyed using in Tokyo, and I was tired of having to buy new 8-ride tickets every few days, so I got a Clipper card and tried it out.

The card is easy enough to use, but the experience refilling my balance on the card has been less than stellar. I'm not about to tie my Clipper card to my credit card account, effectively turning it into a backdoor for a thief to clean me out (the "autoload" feature they push on their website). I was hoping to be able to refill it manually using an automated machine, just like I always did with my Suica card.

It turns out that there are a whopping 7 "Add Value" machines in the entire Bay Area: two in San Rafael, one in Sausalito, one in Oakland, two in downtown San Francisco, and one on the freaking Golden Gate Bridge (I guess for the toll-booth workers?). Fortunately, for those of us whose commute doesn't include one of those 7 locations, you can also add to your Clipper card balance at most Walgreens locations.

And here is where my experience with Clipper takes a nose-dive. First, not all Walgreens locations are equipped to add money to your Clipper card balance. There is, however, a map of the locations on the Clipper website. Unfortunately for me, the Walgreens one block from my office in San Mateo is not on the list and, when asked in person, I received the same look one would expect had I asked them if sold live Jabberwockies.

So, each time I need to refill the balance on my card, I hop in the car and drive two miles to the Walgreens nearest my home. Two miles isn't particularly far, but it does feel a little odd to have to drive somewhere so I can pay for public transportation. Anyway, I only have to do it once every couple of weeks, so it isn't a big deal; just a minor annoyance.

What is more annoying about the experience is that apparently only managers have the specialized training necessary to work the Clipper card "add value" device they keep behind the counter. So the poor checkout clerk has to page for the manager who, after finishing his dooby, mosies up to the front counter and fumbles with the machine until (hopefully) it actually has the balance on it I paid for. This past time, my wife and I had to repeatedly tell other customers that they might want to get in the other line because we were going to be a while. Ten minutes in fact.

The good news is that, with the name change from Translink to Clipper, it looks like they have added an option to refill your card balance online. I'm planning on trying that the next time I need to update my balance. I might miss the biweekly visit to the bloodshot-eyed Walgreens manager, though.

Crappy Code Hopscotch

I'm officially coining the term "crappy code hopscotch" to refer to the stupid games you have to play to workaround crappy code. I guess it could equally well refer to that feeling of being surprised by the effects of crappy code in any otherwise simple task, which might not be altogether unlike the feeling of unpleasant surprise you would get if someone were to throw a pile of dog poo in your hopscotch square.

The term popped into my head today while doing some MySQL wrangling; I was testing a stored function that called LOWER() on the results of CONCAT_WS(). Sounds simple enough: lower-case the result of concatenating strings with a separator. Check this output from MySQL 5.1:

mysql> SELECT LOWER(CONCAT_WS(' ', 'MySQL', 'scores', 'a', 0));
+--------------------------------------------------+
| LOWER(CONCAT_WS(' ', 'MySQL', 'scores', 'a', 0)) |
+--------------------------------------------------+
| MySQL scores a 0                                 |
+--------------------------------------------------+

Silent lower-case fail.

The problem, it seems, is that CONCAT_WS() doesn't convert the numeric argument to a string, but rather decides to convert *all* of the parameters to BINARY types and, as a result, returns a BINARY value. To it's credit, at least LOWER() is documented as being a no-op on BINARY values, hence the useless output shown above. What amazed me is that not just the undocumented, unintuitive behavior of CONCAT_WS() but that MySQL did not emit a single warning when LOWER() returned a value without, you know, lower-casing it.

So out of nowhere, I find myself playing crappy code hopscotch. I can explicitly either cast the numeric argument to CONCAT_WS() to a string or else let CONCAT_WS() return a BINARY value and explicitly convert that back to a string before passing it to LOWER().

Two crappy boxes to pick from and I got to put my foot in one of them.

Invent with Python

Al Sweigart gave a presentation of his book, Invent Your Own Computer Games with Python, to Baypiggies tonight. His book is aimed at kids that are interested in learning how to program. He said he didn't have a particular age range in mind, but I would say from experience it would probably be fine for anyone age 8 to 15 with an interest in computers.

I was impressed with the overall tone and layout of his book. And his choice of teaching programming via writing simple computer games is right on the money. He mentioned that what got him hooked on programming was tinkering around creating simple games when he was kid; I'd venture that was what got a great many of the best engineers I've met started. In addition, he choose to teach programming concepts via Python, which I also agree is a great language for learning because it is expressive, easy to understand, and yet powerful to build professional applications.

In his presentation, Al accurately pointed out that there is a trend to try and simplify programming for kids until it resembles building with duplo blocks and that really isn't helpful for kids nor interesting for them. I concur enthusiastically. Projects like Scratch are neat, but seem patronizing to me. I learned on BASIC and Pascal and I don't doubt kids today are just as capable. That said, BASIC and Pascal are dated now; python is just as easy to learn yet more powerful and modern so it is a great choice.

Another difference between Al's book and many intro books is that his programs are short, fun, and mostly text. Of course, every kid dreams of writing graphical games like the video games they play but that is, frankly, not realistic. Again, Al doesn't lie to his audience; he presents fun text-based games that kids can tinker with. He starts with a simple guessing game, then hangman, tic-tac-toe, and othello. Towards the end of the book, he does introduce pygame and shows how to use it to make simple graphical games, but the vast majority of the book focuses on teaching fundamental concepts via text-based games.

I actually taught introductory computer programming to high school students, age 14 and 15, a number of years ago. Back then we used C, but I was surprised to find that Al presents software concepts in the same order I did and even uses the same games to drive those concepts home. If I could teach the same class today in python, Al Sweigart's Invent Your Own Computer Games with Python is the book I'd want to use.

Overall I was quite impressed with the great job Al did with the book and appreciate him taking the time to talk about it, and the process of writing it, to us at Baypiggies tonight.

P.S. I should mention that he has published the book under the Creative Commons license so it is free to read; you can even download the latest edition off his website. Amazon sells it in dead-tree format too, but you should hold off because the second edition will be going to print soon.

Good Day

All of our sea mail from Japan arrived and was just delivered. In addition, my new MacBook Pro I ordered last week (right after the revision bump) arrived today too. Looks like I'm going to be busy this week. I just hope I can find time to make it to BayPiggies this Thursday.

Subversion sucks

While I was away in Tokyo, NTTMCL switched from CVS to Subversion for their version control system. Perhaps it is just that I'm too accustomed to CVS's eccentricities, but so far I have to say the Subversion sucks. While I'm sitting here waiting for the checkout of one of our heavily-branched repositories to complete (45 minutes and counting!), I took the opportunity to read a little about how much more wonderful Subversion is than CVS.

So far, the best I've come up with is that Subversion is newer, therefore it is better. Yay. With subversion, I just get the delight of knowing I'm playing with a fresh(er) turd.

Sure, CVS sucks too. What bothers me about Subversion is that it sucks at least as much as CVS without giving anything in return. At least with CVS, I can tag a release or create a branch without having to make a whole other copy of the repository (on each developer's machine, no less!). At least with CVS, I can diff and merge files between branches or tags without developing a Repetitive Strain Injury. At least with CVS, the repo files are text so I can recover when it screws up. At least with CVS, I don't have to run a friggin' web server just to do revision control.

So, yeah, maybe I'm just an old fogey. Or maybe Subversion sucks so much, it actually makes me long for CVS. Wouldn't that be sad.

Help me, I'm in RPM Hell

Dear Internet,

Surely there must be a better way to install packages on linux. For better or worse I've been locked in the FreeBSD ivory tower for the better part of 10 years. But now I am assigned to a project that is using linux and I find myself yearning for BSD-style package management. Specifically, I am looking for:

• A way to find a package for my OS (in this case, Red Hat Enterprise Linux 5, 64-bit).
  
• Download that package and the packages for all of its dependencies.
  
• Install a package and all of its dependencies onto a host that is not connected to the Internet.
  
• Is command-line based.
  

In FreeBSD, you can use the FreeBSD packages database to locate the desired package and download it to your system in a format that you can install offline. Getting all of the dependencies it a little trickier, but I wrote a simple perl script some years ago that does that using the FreeBSD ports collection.

Obviously linux has the rpm format for its packages but I'm finding that searching for rpms and identifying all of their dependencies is just as manual of a process as it was 10 years ago. For example, the yum command can install a package and its dependencies, but does not seem to support downloading the rpms for those packages to reproduce the process on an offline machine. Surely there must be a way.

If anyone could point me to a tool for linux that satisfies the 4 goals above, I would be grateful.

P.S. In a case of "it's a small world after all", I went to elementary school through high school with the author of yum, Seth Vidal.

Soil and "Pimp" Sessions

Soil and "Pimp" Sessions is a Japanese jazz band that I've taken quite a liking to. I first learned about them when they released a single with Shina Ringo called "カリソメ乙女" (Karisome Otome) back in 2006. They have had a number of videos on YouTube which I enjoyed, but I just couldn't get my hands on one of their albums. It doesn't look like they have a distributor in the U.S. and none of the record stores I visited in Japan stocked them either.





So you can imagine my surprise and delight when iTunes started carrying their albums around November of last year. The U.S. iTunes store even. I've since stocked up bought 20 or so songs of theirs and have yet to be disappointed. The best I can tell, the U.S. iTunes store is selling all of their albums.

To top it all off, Shina Ringo's latest album, 三文ゴシップ (sanmon gossip) not only includes the 2006 Karisome Otome single, but includes another awesome collaboration　with Soil and Pimp Sessions: マヤカシ優男 (Mayakashi Yasaotoko). There isn't a video for it, but you can preview the song on YouTube. Don't worry, the lyrics for this song are all in English.

Even though they are a Japanese band, since it is jazz, most of the songs have no lyrics. That said, What few words there are do tend to be English. Which makes them a very approachable band to international audiences. In fact, right now they are in the middle of a European Tour. They have a live show schedule on their web site; I know I'll be watching to see when they come to San Francisco.