numguess.swift

import Foundation

// Reads a string from the terminal with an optional default value
func inputString(prompt: String, def: String = "") -> String {
	print(prompt + " ", terminator: "")
	fflush(__stdoutp)
	let handle = NSFileHandle.fileHandleWithStandardInput()
	let data = handle.availableData
	var result = NSString(data: data, encoding: NSUTF8StringEncoding) as! String
	result = result.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceAndNewlineCharacterSet())
	return result == "" ? def : result
}

// Reads a number from the terminal with an optional default and minimum value
func inputNumber(prompt: String, def: Int? = nil, min: Int? = nil) -> Int? {
	var value = Int(inputString(prompt))
	if value == nil { return def }
	if min != nil { value = value < min ? min : value }
	return value
}

// Seed the random generator
srandom(UInt32(time(nil)))

print("Welcome to NumGuess Swift version!\n")
var name = inputString("Enter your name:", def: "Player")
var limit = inputNumber("\nWelcome \(name), enter upper limit:", def: 10, min: 10)!
let maxTries = Int(log2(Double(limit))) + 1
let maxTries10 = Int(Double(maxTries) * 1.1)

repeat {
	print("\nGuess my number between 1 and \(limit)!\n")
	var num = random() % limit + 1
	var tries = 0
	var guess : Int?

	repeat {
		guess = inputNumber("Guess:")

		switch guess {
		case nil:
			print("That's just plain wrong.")
		case let g? where 1...limit ~= g:
			tries += 1
			print(guess < num ? "Too low!" : "Too high!")
		default:
			print("Out of range.")
		}

	} while guess != num

	let triesWord = tries == 1 ? "try" : "tries"
	print("\nWell done \(name), you guessed my number from \(tries) \(triesWord)!")

	switch tries {
	case 1:                     print("You're one lucky bastard!")
	case 2..<maxTries:          print("You are the master of this game!")
	case maxTries:              print("You are a machine!")
	case maxTries...maxTries10: print("Very good result!")
	case maxTries10...limit:    print("Try harder, you can do better!")
	default:                    print("I find your lack of skill disturbing!")
	}

} while "Y" == inputString("Play again [y/N]?").uppercaseString

print("\nOkay, bye.")