UInt16Sequence

UInt16Sequence.swift

import Foundation

struct UInt16Sequence: Sequence, IteratorProtocol {
    var data: Data

    init?(data: Data) {
        guard data.count % 2 == 0
            else { return nil }
        self.data = data
    }
    
    var currentIndex: Int = 0

    mutating func next() -> UInt16? {
        return self.data.withUnsafeBytes { (uint16Pointer: UnsafePointer<UInt16>) -> (UInt16?) in
            guard self.currentIndex < data.count / 2 
                else { return nil }
            
            defer { self.currentIndex += 1 }
            return uint16Pointer[self.currentIndex]
        }
    }
}

let data = "a".data(using: .utf16)!
let uint16sequ = UInt16Sequence(data: data)!
for uint16 in uint16sequ {
    print(String(uint16, radix: 16, uppercase: false))
}