If you know one other language really well, Objective-C should take a week or two to get use to.
To understand all the design patters, apple HIG, XCode, profiling, libraries, debugging, app submission, etc, these combined is where youll sink your time to learn iOS development. Imo, Objective-C is the easy part.
I had 0 objective-C experience, but I made it work. It was a bit of a frustrating experience. Many times I found myself writing Objective-C boilerplate-ish code that I had 0 clue what it was doing, considering this is a hobby / for fun project I just wanted it working.
It's not easy to google the answer to, "Why did I just add this new keyword after this colon in this random .h file.."
I didn't want to spend the next month reading Objective-C for beginners, I know what a for loop is, I also know what constructors are. I just wanted to use the language.
I loved Smalltalk and I love Objective-C at a deep level. The Objective-C runtime is incredibly powerful and its method dispatch is astonishingly efficient considering what it does. It is not as fast as vtables, but it isn't as fragile either.
It might well interest you to know that WebObjects (I'm talking 1997 here) ran on HP-UX, SunOS, AIX, and one other popular Unix of the day that slips my mind and it too shipped with a lively scripting language called WebScript which was not so different from a minimal Swift today.
The thing is, once you dig into the Objective-C runtime and spend a bit of time trying to write an interpreter, you start to realize that the interpreter almost writes itself. Swift is far from the first language built atop the Objective-C runtime.
Consider FScript (http://www.fscript.org) has been around for well over a decade and does more or less the same thing except it gives you something closer to Smalltalk than Javascript and it includes some advanced matrix manipulation goodies as well.
The majority of the people squealing with glee over the introduction to Swift seem to be the sort of people I wouldn't care to work with. If a bit of syntax puts you off so much, lord help you when a truly new paradigm hits.
Swift looks to have some nice features, but it seems to be missing the low level access to the runtime that advanced developers can use like default message handlers (forwardInvocation:/doesNotUnderstand:/methodForSelector: kinds of stuff) and the ability to fiddle method dicts at runtime which can be very useful for intercepting strange errors and unexpected code paths.
So, yes, I do LOVE Objective-C. It is my second favorite language to work in after Smalltalk and to those claiming that Swift will help them move over from Android because it less verbose - lets remember Java is the most boilerplate per capability language I've seen since COBOL. I don't know what those people are talking about.
The only thing that got in the way was the difficulty using the code away from OS X or iOS, and the fact that a lot of libraries for things like database access (especially those intended for iOS) were never intended to be used in a long running process. I found slow (3 week) memory leaks that someone writing an iOS app would never have hit.
If thzt sjunds like fun tj yju, thzn gj fjr Jboective-C.
[ ] does not mean method call, it is the syntax for a message send.
Objective-C is a super set of C, adding an Smalltalk like object system to C. The delimiters say "I am sending a message", which is different to a method call. Also, without them the language would be much more difficult to parse, and future changes to C could break the language. It's lasted well (first appeared in 1993). Not as long as Lisp, perhaps it needs more [ ] :)
1983, actually.
In Smalltalk and Objective-C, the target of a message is resolved at runtime, with the receiving object itself interpreting the message. ... A consequence of this is that the message-passing system has no type checking.
Swift is shit. I suspect it will die in a couple years, like the misguided effort to get people to adopt the Java bridge or WebScript before that.
@lazy var asHTML: () -> String = {
[unowned self] in
if let text = self.text {
return "<\(self.name)>\(text)</\(self.name)>"
} else {
return "<\(self.name) />"
}
}
There have been a lot of C-based object-oriented APIs over the years. GObject has a C API. On the Mac, there's Core Foundation and a bunch of other OS X APIs that are built on top of it. For over a decade on X11, before gtk and Qt even existed, the closest thing there was to a standard graphical environment was Motif (the corresponding desktop environment was CDE), and Motif was built on top of Xt. Xt was yet another C-based object system, although it was specialized for designing UI components.
This is all well and good but you end up with a ton of boilerplate code that does nothing but manage the lifecycles of the object instances (retain/release for example), and lends itself to extremely verbose function calls in place of object methods.
One possible solution is to put together some really elaborate preprocessor macros to make it look like you have extended the C language to include special syntax for your object system, so you can at least replace this:
obj foo = obj_factory(); int c = obj_getNumberOfElements(foo);
...with something more compact like this:
obj foo = [Obj new]; int c = [foo numberOfElements];
(the second example is ObjC-ish but the former is nothing in particular other than just what the typical C object APIs tend to look like)
The only catch is that the little mini-language you are extending C with using macros can't use existing C syntax, because you can only add to the language, not alter the behavior of existing operators. So, you can't just do method calls using a dot syntax on the instance (such as foo.numberOfElements()). So, you have to come up with something new. Maybe you always liked Smalltalk, and maybe you even based much of behavior of your object system on how Smalltalk objects behave and interact? If so, you might settle on the bracket notation. This has the added benefit of making it very clear when a chunk of code is run-of-the-mill C versus when the code is triggering the syntactic sugar you created with macros to add support for your object system to the C language.
C++ doesn't exist yet, or else you might've just gone with that instead of rolling your own thing. Eventually C++ does exist, and you start to feel a little primitive for sticking with the weird macro language. You eventually build your mini-language into a C compiler so you don't have use the macros anymore. You experiment with some new alternatives to the syntax that are more conventional, but no one uses them. Many developers like that the non-C-ish syntax makes it easy to distinguish between straight C code vs. interactions with the object system, which has its own set of rules and conventions.
Anyway, that's mostly speculation, but something like that story is how I've always thought Objective-C evolved over the years. I don't mind it nearly as much as long as I don't think of it as a separate programming language from C (like C++ or Java or pretty much anything else these days), but rather think of it as C with some useful syntactic sugar that gets rid of a ton of boilerplate code for a particular C-based object-oriented API.