Character + Stideable.swift

extension Character: Strideable {
    public func distance(to other: Character) -> Int {
        let selfValue = self.unicodeScalars.first?.value ?? 0
        let otherValue = other.unicodeScalars.first?.value ?? 0
        return Int(otherValue - selfValue)
    }

    public func advanced(by n: Int) -> Character {
        guard let scalar = self.unicodeScalars.first else {
            fatalError("Cannot advance an empty character")
        }
        
        guard self.unicodeScalars.count == 1 else {
            fatalError("❌ Cannot advance when a character is made by combined code points. This is a limitation of Swift.")
        }
        
        let newValue = Int(scalar.value) + n
        guard let newScalar = Unicode.Scalar(newValue) else {
            fatalError("Resulting scalar value is invalid")
        }
        return Character(newScalar)
    }
}


let a: Character = "a"
let z: Character = "z"

let alphabeticalRange = a...z
print(alphabeticalRange.count) // 26 
for letter in alphabeticalRange {
    print(letter) // prints a to z...
}