Why "For empty arrays and dictionaries, use type annotation. "

[oneGain]

Type Inference

Prefer compact code and let the compiler infer the type for constants or variables of single instances. Type inference is also appropriate for small, non-empty arrays and dictionaries. When required, specify the specific type such as CGFloat or Int16.

Preferred:

let message = "Click the button"
let currentBounds = computeViewBounds()
var names = ["Mic", "Sam", "Christine"]
let maximumWidth: CGFloat = 106.5

Not Preferred:

let message: String = "Click the button"
let currentBounds: CGRect = computeViewBounds()
var names = [String]()
Type Annotation for Empty Arrays and Dictionaries
For empty arrays and dictionaries, use type annotation. (For an array or dictionary assigned to a large, multi-line literal, use type annotation.)

Preferred:

var names: [String] = []
var lookup: [String: Int] = [:]

Not Preferred:

var names = [String]()
var lookup = [String: Int]()

NOTE: Following this guideline means picking descriptive names is even more important than before.

Why "For empty arrays and dictionaries, use type annotation. "

[Jessy Catterwaul]

Hey!

I think this is addressed in #269.