Isreali ID Validator (swift)

IsrealiID.Validator.swift

import Foundation

func israeliIDValidator(idNum: String) -> Bool {
    guard Int(idNum) != nil else { return false }
    return ("00000000" + idNum).suffix(9).enumerated().reduce(0) {
        let step = Int(String($1.1))! * ($1.0 % 2 + 1)
        return $0 + (step > 9 ? step - 9 : step)
    } % 10 == 0
}