>
> However, Roland got it slightly wrong, according to the documentation. This:
>
> print (“\(myObj)”)
>
> never uses debugDescription, only description. To use debugDescription (if it
> exists, or description instead):
>
> debugPrint (“\(myObj)”)
Dunno about the documentation - I’m remembering a WWDC video which said one
falls back to the other. So I tested it in a playground. \(variable) appears to
do as suggested, uses description if that exists, falls back to
debugDescription if it doesn’t and prints the class name if neither do.
Surprisingly all debugPrint() does is not, as you might expect, use the
debugDescription in preference, but just puts quotes around the whole thing and
still uses description if it exists. That feels wrong.
class IHaveNothing{}
class OnlyDebugPrintable : IHaveNothing, CustomDebugStringConvertible
{
var debugDescription : String { return "I am
CustomDebugStringConvertible" }
}
class HasTheLot : OnlyDebugPrintable, CustomStringConvertible
{
var description : String { return "I have the lot" }
}
let a = IHaveNothing()
let b = OnlyDebugPrintable()
let c = HasTheLot()
print( "\(a)” ) // IHaveNothing
print( "\(b)” ) // I am CustomDebugStringConvertible
print( "\(c)” ) // I have the lot
debugPrint( "\(a)” ) // “IHaveNothing"
debugPrint( "\(b)” ) // “I am CustomDebugStringConvertible"
debugPrint( "\(c)” ) // “I have the lot"
_______________________________________________
Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)
Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com
Help/Unsubscribe/Update your Subscription:
https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com
This email sent to arch...@mail-archive.com
