What is a fast way to convert a string of two characters to an array of booleans?

Question

I have a long string (sometimes over 1000 characters) that I want to convert to an array of boolean values. And it needs to do this many times, very quickly.

let         


        

Answer 1

import Foundation

let input:String = "010101011001010101001010101100101010100101010110010101010101011001010101001010101100101010100101010101011001010101001010101100101010100101010"
var start  = clock()
var output = Array(count: input.nulTerminatedUTF8.count, repeatedValue: false)
var index = 0
for val in input.nulTerminatedUTF8 {
    if val != 49 {
        output[index] = true
    }
    index+=1
}
var diff = clock() - start;
var msec = diff * 1000 / UInt(CLOCKS_PER_SEC);
print("Time taken \(Double(msec)/1000.0) seconds \(msec%1000) milliseconds");

This should be really fast. Try it out. For 010101011010101001000100000011010101010101010101 it takes 0.039 secs.