Extends Swift's Array structure by providing stepping functionality recursively using an external variable.

steppers

// Created on 6/2/15 by Christopher Gonzalez D.K.A. @gchriswill https://github.com/JWShroyer
// Reviewed and optimyzed by Josh Shroyer D.K.A @JWShroyer https://github.com/JWShroyer
// Last revision on 7/11/15 by @gchriswill and @JWShroyer

extension Array {
    
    mutating func countForward(inout counter c: Int) -> Void {
        
        var s = self.count - 1
        c = c < s && !(0 > c) ? (c + 1) : 0
        
    }
    
    mutating func countBackward(inout counter c: Int) -> Void {
        
        var s = self.count - 1
        c = 0 >= c || c > s ? s : (c - 1)
        
    }
    
}

@JWShroyer, Here is the gist.
The protocol version will be uploaded through a separate file in this repository... 👾