swift动态编写NSPredicate

value as NSObject does the trick:var keyValues: [String: AnyObject] = ["name" : "John Doe", "age" : 39]var predicates = [NSPredicate]()for (key, value) in keyValues {    var predicate = NSPredicate(format: "%K = %@", key, value as NSObject)    predicates.append(predicate) }var compundPredicate = NSCompoundPredicate.andPredicateWithSubpredicates(predicates)println(compundPredicate)Output:name == "John Doe" AND age == 39