An example of the Schwartzian Transform in Swift

SchwartzianTransform.swift

// Schwartzian Transform

let list = ["a", "aa", "aaaa"]

// Create tuples with the attribute to sort on in the 2nd position
let sorted = list.map { ($0, Int($0.characters.count)) }
    .sort { $0.1 > $1.1 }
    .map { $0.0 }
print(sorted)

// The transform isn't actually necessary in Swift as the array can be sorted in place
let sorted2 = list.sort { $0.characters.count > $1.characters.count }
print(sorted2)