binary data class

BinaryData.swift

import Foundation

func +(lhs: BinaryData, rhs: BinaryData) -> BinaryData {
    return BinaryData(lhs.data + rhs.data)
}

class BinaryData : CustomStringConvertible, Indexable {
    var data: [UInt8] = []
    
    // we allow data to be empty
    init(_ input: [UInt8] = []) {
        data = input
    }
    
    convenience init(byteString b : ByteString) {
        // allow spaces
        assert (b.isValidByteString(spaces: true),
            "found some bad characters in input bytes \"\(b)\"")
        self.init(b.hexByteStringToIntArray())
    }
    
    var description : String {
        get {
            let sa = data.map { intToHexByte($0) }
            return sa.joinWithSeparator("")
        }
    }
    
    var count : Int {
        get {
            return self.data.count
        }
    }
    
    var endIndex: Int {
        get {
            return data.count
        }
    }
    
    var startIndex: Int {
        get {
            return data.count
        }
    }
    
    subscript (position: Int) -> UInt8 {
        get {
            return data[position]
        }
    }

    subscript (r: Range<Int>) -> BinaryData {
        get {
            var ret: [UInt8] = []
            for (i,v) in data.enumerate() {
                if r.contains(i) {
                    ret.append(v)
                }
            }
            return BinaryData(ret)
        }
    }
}