You have been spared the terrible pun for this title, I knew the last one was trouble when it was typed in.

So, in the earlier article Operator Overloading — Tailor Swift To Your Needs, you saw how you could add functionality to already existing operators to extend their functionality to work with new classes, or in that post’s case, existing ones that it might make sense with.  Now, what if you want a completely new operator?  What if you have functionality so unique, that no current operator makes sense?  That’s where custom operators comes in.  You can declare your own operator and have it run whatever code you want.  Now, like last time, this is a very powerful, but very dangerous capability.  You COULD have it play sounds, make network calls, draw something to screen, or any number of annoying things, but you really should not have those in your operator overloading or custom operator methods.  They are meant to make things more readable, not less.  Unless you use some emoji for a loudspeaker in your operators, you really shouldn’t have it play sounds, and even if you do, why not just use a method?

Also of course, since these are meant to increase readability, you have to be careful about using these.  For instance, can you tell me what the ” #$^&* ” operator does?  Obviously somebody new to a codebase needs some time to get up to speed with it, and even normal functions will take some time to learn the intricacies of.  However, if you compress a gigantic algorithm into a custom operator, that may take longer to figure out than a well named method doing the same.

Nonetheless though, if you use custom operators sparingly, well document them, and don’t give them side effects (like making network calls, playing sounds, etc), they can very useful for increasing legibility and decreasing the character count in your code.
[Read more…]

Time to start moving away from pure Swift posts, and start talking about making iOS apps.  Though we will be talking about doing so with Swift, of course.  Today we are going to talk about the Five Execution states of an iOS app.  The iOS operating system itself changes which state your app is in, and gives you a chance to make appropriate changes during most of the transitions.
[Read more…]

We have previously discussed generic functions on this blog in the post Generic Functions in Swift.  There is one more aspect to generics in Swift that we have not covered yet, Generic types.  Generic types let you write a named type (class, enumeration, or structure) that can accommodate different types in its implementation.

Now, that just sounds silly right there, why would you want to handle other types in your type?  Well, the main and most predominant reason is for collections.  The best example of this, is the built in Array and Dictionary types.  The shorthand is a lot more readable, and is the recommended way to create Arrays and Dictionaries, but really, [Int] and [String : Int] are actually Array<Int> and Dictionary<String, Int> under the hood.  See those angle brackets?  Yep, those are the same kind of angle brackets used in generic functions.
[Read more…]