Verbs and nouns
Verbs and nouns êŽë š
Available from Swift 3.0
This is the part where some people will start to drift off in confusion, which is a shame because it's important.
Here's are some quotes from the Swift API guidelines:
- "When the operation is naturally described by a verb, use the verbâs imperative for the mutating method and apply the âedâ or âingâ suffix to name its nonmutating counterpart"
- "Prefer to name the nonmutating variant using the verbâs past participle"
- "When adding âedâ is not grammatical because the verb has a direct object, name the nonmutating variant using the verbâs present participle"
- "When the operation is naturally described by a noun, use the noun for the nonmutating method and apply the âformâ prefix to name its mutating counterpart"
Got that? It's no surprise that Swift's rules are expressed using lingustic terminology â it is after all a language! â but this at least gives me a chance to feel smug that I did a second degree in English. What it means is that many methods are changing names in subtle and sometimes confusing ways.
Let's start with a couple of simple examples:
myArray.enumerate()
myArray.enumerated()
myArray.reverse()
myArray.reversed()
Each time Swift 3 modifies the method by adding a "d" to the end: this is a value that's being returned.
These rules are mostly innocent enough, but it causes confusion when it comes to array sorting. Swift 2.2 used sort() to return a sorted array, and sortInPlace() to sort an array in place. In Swift 3.0, sort() is renamed to sorted() (following the examples above), and sortInPlace() is renamed to sort().
TL;DR
This means you need to be careful because in Swift 2.2 sort() returned a sorted array, but in Swift 3.0 sort() sorts the array in place.
Other Changes in Swift 3.0