Open Radar

 
toInt() is far slower than creating an NSScanner and scanning. There is no toDouble(), so I wrote one, then in timing it discovered this. All of these would be blown away by low-level scanning without alloc/release of an NSScanner.

import Cocoa

extension String {

func parseDouble() -> Double? {
	if self == "" {
		return nil
	}
	var scanner = NSScanner(string:self)
	var n = 0.0
	if scanner.scanDouble(&n) {
		return n
	} else {
		//NSLog("Invalid double \(self)")
		return nil
	}
}

func parseInt() -> Int? {
	if self == "" {
		return nil
	}
	var scanner = NSScanner(string:self)
	var n = 0
	if scanner.scanInteger(&n) {
		return n
	} else {
		//NSLog("Invalid integer \(self)")
		return nil
	}
}

func parseHexInt() -> Int? {
	if self == "" {
		return nil
	}
	var scanner = NSScanner(string:self)
	var n:CUnsignedInt = 0
	if scanner.scanHexInt(&n) {
		return Int(n)
	} else {
		//NSLog("Invalid hex integer \(self)")
		return nil
	}
}

}

let count = 10000
let s = "1234"
var t1 = CFAbsoluteTimeGetCurrent()
for var i = 0; i < count; ++i {
	var n = s.toInt()
}
var t2 = CFAbsoluteTimeGetCurrent()
NSLog("toInt took \(t2-t1) s")

t1 = CFAbsoluteTimeGetCurrent()
for var i = 0; i < count; ++i {
	var n = s.parseInt()
}
t2 = CFAbsoluteTimeGetCurrent()
NSLog("parseInt took \(t2-t1) s")

t1 = CFAbsoluteTimeGetCurrent()
for var i = 0; i < count; ++i {
	var n = s.parseDouble()
}
t2 = CFAbsoluteTimeGetCurrent()
NSLog("parseDouble took \(t2-t1) s")

// toInt took 4.900514960289 s
// parseInt took 0.793006002902985 s
// parseDouble took 0.780673027038574 s