`tap:` method for Swift borrowed from Ruby. ( a little broken, Cast needed)

tap.swift

import Cocoa

extension NSObject {
    func tap(blk:(AnyObject) -> Void) -> Self {
        blk(self as NSObject)
        return self
    }
}

// Alternative, you will need to specify the type :: view:NSView = ...
extension NSObject {
    func tap<T>(blk:(T) -> Void) -> T {
        blk(self as T)
        return self as T
    }
}

let nsarray:NSMutableArray = NSMutableArray(array: [1,2,3,4,5]).tap { x in
    x.replaceObjectAtIndex(2, withObject:"Record")
}
println("NSArray \(nsarray)")

let view:NSView = NSView(frame: NSRect(x:0, y:0, width:10, height:10)).tap { v in
    var mv = v as NSView
    mv.hidden = false // to set hidden, we need to cast as NSView :(
    println("VIEW \(v.frame)")
}