D言語からObjective-CとCocoaAPIを使いたい

{
    "authors": ["hidhok"],
    "description": "A D/Objective-C Cocoa application.",
    "name": "number",
    "dflags": ["-L-framework", "-LCocoa"],
    "sourceFiles": ["../cocoa/stringAPI"]
}               

/**
 *       number/source/app.d
 *    「MAC OSX COCOA プログラミング 第３章 Objective-C」から
 */		
module number.main;
import core.attribute : optional, selector;
import std.stdio;
import cocoa.strings;

void main(string[] args) {
    NSMutableArray array = NSMutableArray.alloc.init;
    foreach(i; 0..10) {
        NSNumber newNumber = NSNumber.alloc.init(i * 3);
        array.addObject = newNumber;
    }
    foreach(i; 0..10) {
        NSNumber numberToPrint = array.objectAtIndex(i);
        // NSLog("The number at index %d is %@".toNs, i, numberToPrint);
        // writefln("The number at index %d is %2d", i, numberToPrint.toInt);
        writefln("The number at index %d is %2s", i, numberToPrint.toStr);
    }
}