BUG in Swift NSDataDetector detected :)```

Swift
1 
 var parseDATE: String {
        print(self)
        let detector   = try? NSDataDetector(types: NSTextCheckingResult.CheckingType.date.rawValue)
        let matches    = detector?.matches(in: self, options: [], range: NSMakeRange(0, self.utf16.count))
        let dt         = matches?.first?.date
        if dt         == nil { return parseERROR }
        let fmt        = DateFormatter()
        fmt.dateFormat = "yyyy-MM-dd HH:mm:ssZZZZZ"
        let s = String(fmt.string(from: dt!))
        return s.Left(19)
    }

I have used the above code to validate Strings as Dates in Swift for some time. It will extract any valid date from a phrase and return an SQLDate formatted string

However, today I found there is an :lady_beetle: in NSDataDetector. it crashes if the date is in the year 2100 or beyond or the year < 1700

So it is fine for MOST things… but not everything

2

Gonna have to forgive me as I’ve only been really looking it Swift for 3 days, have you tried wrapping it in a do-catch block?

3

It is not a matter of catching the error, that I can do… its the fact that I think a date range of 1700 to 2100 is rather short sighted… Genealogy for example would have to use something else

1 Like
4

I would agree with you that it does appear very short sighted, but it sadly isn’t surprising.

I was just reading that it appears Swift will crash an app on error/exception, which is the opposite behavior of Objective-C. A change Apple made with 10.14, before that Obj-C would crash on error/exception.

I’m still going over in my head the differences between structs and classes. It feels like the main differences are classes can be subclassed and in Xojo terms when passed to a function operate as “ByRef”, while structs operate like “ByVal”. Both can be mutable or immutable, but even if you make an immutable object, you can make it mutable via functions.

5

The way Swift handles Classes, Structure and even Enums is WAY WAY more flexible.

for example

  public enum linePattern : Int {
        case none
        case solid
        case dotted
        case dashed
        func pattern() -> [CGFloat] {
            switch self {
                case .none  : return []
                case .solid  : return [1,0]
                case .dotted : return [2,2] // 1100
                case .dashed : return [4,4] // 11110000
            }
        }
    }


let pattern = linePattern..dotted.pattern()
1 Like