Tuesday, November 19, 2002

dumb advertising works for dumb people? "I'm so simple that only a Mac can help me." Yo Yo Ma Maybe it's just me, but I don't like it when things are marketed for dummies. All those books like "Martial Arts for Dummies" - they scare me. What are dummies doing with martial arts anyway? And these switch commercials from Apple. I don't get it. How stupid am I supposed to be before I have to switch? I don't get it. Will somebody please explain to me why all these ads are aimed at people who couldn't get a clue if they were doused in a barrel of clue musk? 6:27:23 PM

What to do when your Cocoa app dies with a sig11 BlogApp has exited due to signal 11 (SIGSEGV). By far the most common error I've been making in Objective-C is forgetting to retain objects that are autoreleased. Case in point - I tried executing some SQL onto a database connection and the ObjectiveC runtime immediately crapped out on me with the above error. What I had done is in the init block, I had code that looked like this: static SQLDatabase* database ... database = [SQLDatabase databaseWithFile:path]; The database object is in the autorelease pool since I didn't explicitly invoke the alloc/init mesage handlers. Crap. The fix is simple of course: database = [[SQLDatabase databaseWithFile:path] retain]; and all is well in the world. This isn't quite the same as a NullPointerException in Java though. I forgot to make the database connection at all initially, and I only saw the problem because a unit test failed - invalid number of returned rows. Why? Because Objective-C handles null objects properly so any method I invoked on nil just becomes a no-op. So - what does this mean? Note to self: 1. write more unit tests. 2. learn from stupid mistakes faster 5:59:03 PM

What time is it? Cocoa implements time according to the Network Time Protocol (NTP) standard, which is based on Coordinated Universal Time. The current private implementations of NSDate follow the NTP standard. However, they do not account for leap seconds and therefore are not synchronized with International Atomic Time (the most accurate). [Apple] Huh? I looked up Java's Date representation and I couldn't figure out if it used leap seconds or not. There's a really long winded discussion about leap seconds in the java.util.Date javadoc, but it seems to imply that it depends on the underlying operating system. Thing only get more confusing when reading up on Dan Bernstein's weblog on TAI and UTC time. Aiyeee!!! 3:31:00 PM

© Copyright 2003 Victor Ng.