Random Generator

gistfile1.swift

//  Generates various types of random values
//
//  Created by Patrick Lynch on 6/30/15.
//  Copyright © 2015 Patrick Lynch. All rights reserved.

import Foundation

struct Random {
	
	// Designed for you to swap out for any other core random function
	private static func _random() -> UInt32 {
		return arc4random()
	}
	
	static func index( count: Int ) -> Int {
		return Int(_random() % UInt32(count))
	}
	
	static func index( count: UInt ) -> UInt {
		return UInt(_random() % UInt32(count))
	}
	
	static func element<T>( collection:[T] ) -> T {
		return collection[ index( collection.count ) ]
	}
	
	static func bool() -> Bool {
		return Bool(_random() % UINT32_MAX > UINT32_MAX / 2)
	}
	
	static func probability( probability: Float ) -> Bool {
		return self.value( from: 0.0, to: 1.0 ) >= 1.0 - probability
	}
	
	static func value( from min: Float = 0.0, to max: Float = 1.0 ) -> Float {
		let r = Float(_random() % UINT32_MAX) / Float(UINT32_MAX)
		return min + r * (max - min)
	}
	
	static func value( from min: Double = 0.0, to max: Double = 1.0 ) -> Double {
		let r = Double(_random() % UINT32_MAX) / Double(UINT32_MAX)
		return min + r * (max - min)
	}
	
	static func value( from min: Int, to max: Int ) -> Int {
		return min + Int(_random() % UInt32(max-min))
	}
	
	static func value( from min: UInt, to max: UInt ) -> UInt {
		return min + UInt(_random() % UInt32(max-min))
	}
}