Objective-C

Rohde

So, in my spare time I'm learning some Cocoa on the Mac - you know just to widen my horizon (I do C#/ASP.NET at my day-job) and I absolutely love the Objective-C message sending syntax even though it's kind of verbose. I'll use the example from Hillegass' book (Cocoa Programming for Mac OS X, Second Edition) to contrast C++ (and Java and C# for that matter) with Objective-C:

if (x.intersectsArc(35.0, 19.0, 23.0, 90.0, 120.0))

vs.

if ([x intersectsArcWithRadius:35.0
centeredAtX:19.0
Y:23.0
fromAngle:90.0
toAngle:120.0])

Yes, it's more wordy (and I normally hate wordy languages like Pascal and VB), but rest of the language is just as terse as the other curly-brace languages (although I could do without the brackets [ ...and... ]). So, any of you have any experience with Objective-C and Cocoa, and if so whada you think?

"When you have made evil the means of survival, do not expect men to remain good. Do not expect them to stay moral and lose their lives for the purpose of becoming the fodder of the immoral. Do not expect them to produce, when production is punished and looting rewarded. Do not ask, `Who is destroying the world?' You are."
-Atlas Shrugged, Ayn Rand

Michael Sadlon

I don't see the large improvement. If the argument names matter so much, then do this:

if (x.intersectsArc(
35.0, //intersects Arc With Radius
19.0, //centered At X
23.0, //Y
90.0, //from Angle
120.0 //to Angle
))

Otherwise, it looks like normal C to me. Am I missing something ingenius?

peterchen

No idea at all, but the named arguments would be a big helper for many-param-functions. It helps readability of the code a lot - esp. if it is optional (is it?) so I can be as terse or verbose as the context requires.

To many words
- me, during, while and after reading Atlas Shrugged.

Shog9 0

...Now you have another place for bugs to hide... Think about how many Win32 functions take a structure as a parameter. With named parameters, this is less necessary, as functions with many arguments become less troublesome.

----

Yes, but can you blame them for doing so if that's the only legal way they can hire programmers they want at the rate they can afford?

-- Nish on sketchy hiring practices

Daniel Grunwald

Why not make an arc an object instead of having huge parameter lists everywhere you expect an arc? Add C# 3.0 object initializer syntax and you get:

Arc arc = new Arc { Radius = 35, Center = { 19, 23 }, FromAngle = 90, ToAngle = 120 };
if (x.IntersectsArc(arc)) {
...
}
class Arc {
public double Radius, FromAngle, ToAngle;
public Point Center;
}

Rohde

Yes, that is also a good way to do it. I really like some of the C# 3.0 features.

"When you have made evil the means of survival, do not expect men to remain good. Do not expect them to stay moral and lose their lives for the purpose of becoming the fodder of the immoral. Do not expect them to produce, when production is punished and looting rewarded. Do not ask, `Who is destroying the world?' You are."
-Atlas Shrugged, Ayn Rand

Gary R Wheeler

This seems similar to the named arguments feature available in Ada, one of the few features in that programming language I actively miss in C++.

Software Zen: delete this;

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Rohde

Ada, now there's a language I've looked at many times, but never really tried. Some of the features seems quite nice, but it seems pretty useless for what I do because of lack of toolkits etc, but I guess it's pretty big in Dod.

"When you have made evil the means of survival, do not expect men to remain good. Do not expect them to stay moral and lose their lives for the purpose of becoming the fodder of the immoral. Do not expect them to produce, when production is punished and looting rewarded. Do not ask, `Who is destroying the world?' You are."
-Atlas Shrugged, Ayn Rand

Gary R Wheeler

I have no idea how prominent Ada is even in the defense community any longer. When it was originally developed, the idea was to make Ada the one programming language used throughout the DoD. I don't think that ever materialized.

Software Zen: delete this;

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