Vincent Gable’s Blog

February 4, 2010

Deus Ex Ignorantia

Filed under: Design,Quotes | , , , ,
― Vincent Gable on February 4, 2010
Felten’s Third Law
Given an intractable and complex policy problem, people tend to look to areas they are not experts in to save the day.

For example,

Given a difficult technology policy problem, lawyers will tend to seek technology solutions and technologists will tend to seek legal solutions. … It’s easy to reject non-solutions in your own area because you have the knowledge to recognize why they will fail; but there must be a solution lurking somewhere in the unexplored wilderness of the other area.

— Ed Felton.

January 15, 2010

EULA Today Fail

Filed under: Announcement,iPhone | , , , , , ,
― Vincent Gable on January 15, 2010

The EULA1 for the USA TODAY iPhone App starts off

General

These Terms of Service govern your use of the USATODAY.com website (the “Site”) only and do not govern your use of other USA TODAY services, such as services offered by the USA TODAY print newspaper.

Clearly this invalidates the agreement on the iPhone, since the iPhone App is not “the USATODAY.com website”.

This is mildly embarrassing for USA TODAY, and even more of a fumble for Mercury Intermedia, who built the app. But I can’t think of any way this actually hurts anyone, even in theory. Users are already bound by the App Store Terms and Conditions, so why bother putting your own EULA (that nobody’s ever going to read much less care about) in your app?

1To see the EULA, tap that little i near the bottom left of the homescreen, then tap Terms of Service. The text above was copied from version 1.5 of the USA TODAY iPhone App.

January 13, 2010

Splash Screens Are Evil

Filed under: Design,iPhone,Programming,Usability | ,
― Vincent Gable on January 13, 2010

Splash screens are evil. While branding is important, the proper place for it is in the iconography, optional “About” or “Info” screens, and App Store profiles. The most common interaction pattern with iPhone applications is to launch them frequently, close them quickly, and treat them as part of a set of tools that interact to comprise a single user experience. Splash screens break the perception of seamlessness.

The HIG offers a very useful suggestion for managing launch states, which may be quite slow, depending on the needs of your application. The suggestion is to provide a PNG image file in your application bundle that acts as a visual stand-in for the initial screen of your application. For example, if the main screen for your application is a table full of data, provide an image of a table without data to act as a stand-in. When your data is ready to be displayed, the image will be flushed from the screen, and the user experience will feel more responsive.

In this book, we will explore extensions of this, including a pattern for loading application state lazily

–Toby Boudreaux, iPhone User Experience, page 15; emphasis mine.

I’ve always hated splash screens, from the first time I turned on a computer. They get in the way of what I want to do. I want to write, or draw, or play — but if I launch Word, or Photoshop, or any game, I have to sit through a splash screen before I can get to it.

Branding a splashscreen is putting your name on a purely negative experience. Nobody wants to wait for their computer. Splashscreens, by definition, force you to wait. It’s hard for me to imagine why anyone wants to associate their brand with a computer not doing what customers want.

iPhone 4 Update

Fast App Switching, introduced in iOS 4, makes splash screens a much worse idea. They won’t consistently display, because sometimes the app will really be resuming, not starting for the first time, when the user “launches” it. Forcing a splash-screen to appear on a resume as well means breaking the “multitasking” experience.

December 25, 2009

A C &Puzzler[]

Filed under: Announcement,Bug Bite,C++,Objective-C,Programming | , , ,
― Vincent Gable on December 25, 2009

Here’s a C-puzzler for you!

given this function,

void foo(char* s){
	printf("s is at: %p\n s is: '%s'\n", s, s);
}

and that

char s[] = "Joy!";
foo(s);

prints out

s is at: 0xbffff46b
s is: ‘Joy!’

what will this next line print?

foo(&s); //WHAT WILL THIS DO?

Pick all that apply:

  1. Print “Joy!”
  2. Print garbage
  3. Print the same address for s
  4. Print the a different address for s
  5. Crash
  6. Go into an Infinite loop

Answer

Answer: one and three

Yeah, it’s not what I expected either, especially since:

@encode(__typeof__(s)) = [5c]
@encode(__typeof__(&s)) = ^[5c]

In fact, all of these are equvalent (modulo type warnings):

foo(s);
foo(&s[0]);
foo(&(*s));
foo(&s);

Explanation.

December 18, 2009

Guess Towards the Middle

Filed under: Design,Quotes | , ,
― Vincent Gable on December 18, 2009

Survey researchers call this kind of behavior satisficing – it happens when people taking a survey use cognitive shortcuts to answer questions. In the case of questions about personal behaviors that we’re not used to quantifying (like the time we spend online), we tend to shape our responses based on what we perceive as “normal.” If you don’t know what normal is in advance, you define it based on the midpoint of the answer range.

—Aaron Shaw, writing for Dolores Labs

Related:

Acquiescence Response Bias

the tendency to agree with any assertion, regardless of its content

December 10, 2009

Being a Lisp is a Handicap

Filed under: Accessibility,Programming | , , , ,
― Vincent Gable on December 10, 2009

Being a Lisp Is a Handicap

There are a large number of people who find Lisp code hard to read. I’m one of them. I’m fully prepared to admit that this is a shortcoming in myself not Lisp, but I think the shortcoming is widely shared.

Perhaps if I’d learned Lisp before plunging into the procedural mainstream, I wouldn’t have this problem — but it’s not clear the results of MIT’s decades-long experiment in doing so would support that hypothesis.

I think it’s worse than that. In school, we all learn
3 + 4 = 7 and then
sin(?/2) = 1
and then many of us speak languages with infix verbs. So Lisp is fighting uphill.

It also may be the case that there’s something about some human minds that has trouble with thinking about data list-at-a-time rather than item-at-a-time …
…

I think I really totally understand the value of being homoiconic, and the awesome power of macros, and the notion of the reader. I want to like Lisp; but I think readability is an insanely important characteristic in programming systems.

Practically speaking, this means that it’d be hard for me to go out there on Sun’s (or Oracle’s) behalf and tell them that the way to take the best advantage of modern many-core hardware is to start with S-Expressions before breakfast.

—Tim Bray (emphasis mine)

I’m afraid he’s on to something. We have an amazing ability to parse language. But people aren’t terribly good at building the kinds of stacks needed to parse LISP with their short term memory.

This is the cheese that the rat that the cat that the dog that the neighbor owned bothered chased ate.

Say what?!

(This is the cheese (that the rat (that the cat (that the dog (that the neighbor owned) bothered) chased) ate)).

See the LISP connection?

All functional languages are fighting an uphill battle to be understood. The world we evolved in is stateful (modal) and imperative. We navigate it in a me-at-a-time way. Unfortunately, LISP’s prefix syntax is another, unnecessary, barrier.

The bottom line is that every word of code spends more time being read than written — so writing in a syntax that most people have a hard time reading is one of the worst programming choices imaginable. I believe functional programming languages are well worth learning; but I don’t believe it’s worth suffering a poor syntax.

December 9, 2009

Compile Safer

Filed under: Bug Bite,C++,Cocoa,iPhone,MacOSX,Objective-C,Programming | , , ,
― Vincent Gable on December 9, 2009

Peter Hosey explains what warnings he uses and why. It’s good, but long. Fortunately, you can just grab a script, and enable those warnings in your Xcode projects.

Warnings = Errors

If I could force just one compiler flag on everyone who’s code I use, it would be TREAT_WARNINGS_AS_ERRORS. As a rule, things don’t get improved if they aren’t broken. (How many times have you said “I’ll come back and fix this code later”? Yeah.) Warnings fester and grow on each other, until they cause a real breakage. It’s an inescapable evil of building software with finite resources.

If a warning isn’t worth stopping the build over — it’s not worth checking for in the first place.

Use the Latest Tools

Specifically, if you aren’t using Snow Leopard and Xcode 3.2 to build your Objective-C code, you are crazy. Trust me, painless static analysis is worth upgrading for. It catches maddening memory leaks, not just trivial type errors, like adding an int to an NSArray, that you would catch immediately.

December 7, 2009

Dot Syntax Solution

Filed under: Cocoa,Design,Objective-C,Programming,Usability | , , , ,
― Vincent Gable on December 7, 2009

Surprisingly, the addition of dot syntax to Objective-C 2.0 has been a major source of controversy. I wonder if there’s some kind of Bike Shed effect at work here: the problem dot-syntax causes is trivial1; while the clarity it brings to code is minor. So it essentially boils down to aesthetics. (For the record, I like the dot, even with it’s current flaws, but I don’t believe it’s worth fighting for).

The Actual Problem

The problem is that when you see a.b = c; you don’t know if it’s:

  1. Assigning the b field of a struct to c. This basically compiles down to one move instruction.
  2. Invoking the -setB: method on an Objective-C object. By convention -setB: should update the b property of the object to hold the value c, and nothing else. But it might have side effects, or be really slow.

A Solution

Using a different symbol to access Objective-C properties would remove all ambiguity. Nobody would mistake a@b = c; as assigning to a C-struct. It’s clearly an Objective-C construct.

But personally, I’m not a big fan of the @ character. It’s ugly; it’s noisy; there’re just too many lines in it. I think U+25B8 ‘BLACK RIGHT-POINTING SMALL TRIANGLE’ would make a better choice,

obj▸property = value;

And since ‘▸’ can’t be part of a valid C identifier, you can basically preprocess your code with s/▸/./, then compile it with existing tools.

Of course, it doesn’t matter what character(s) is picked, so long as it’s clearly different from existing C syntax; and you have a way of replacing it with a . before building it.

1 I’ve heard experienced developers complain that dot-syntax = a steeper learning curve for newbies, and that it can be confusing, but I haven’t actually seen one come out and say ‘I spent X hours debugging a problem that I couldn’t see because of it’. The fact is, any situation that dot-syntax would obscure is already pathological. In the end I just can’t see dot-syntax mattering much.

November 17, 2009

Cut To The Chase

Filed under: Announcement,Tips | , ,
― Vincent Gable on November 17, 2009

YouTubeTime.com makes it easy to link to a specific time in a YouTube video.

Do It Yourself Example

To link to 2 minutes & 14 seconds into this video of dancing in a Microsoft store, http://www.youtube.com/watch?v=TSAXEVXvNz8, add #t=2m14s to the end of the url:
http://www.youtube.com/watch?v=TSAXEVXvNz8#t=2m14s.

Did you catch the shoplifting? (via @codinghorror)

November 15, 2009

Social Engineering iPhone Ratings

Filed under: iPhone,Quotes | , , ,
― Vincent Gable on November 15, 2009

The “Sex Jokes Lite” application is clever/manipulative about their ratings. They push people to give 5 star reviews with this little bit of a social contract: in their app-description they say,

“IMPORTANT: If you think the jokes are TOO dirty, please give a 1-star review. If you want them dirtier, give a 5-star review. This way we know what direction to take in the upcoming updates !”

—Dan Grigsby

Clever, but a bit of a dirty trick *rimshot*.

« Newer Posts — Older Posts »

Powered by WordPress