Re: [RFA]: BOOL coding standards (Was: Problem with +numberWithBool: ?)

[Helge Hess]

On 02.02.2004, at 15:17, Richard Frith-Macdonald wrote:
> Until someone (you?) found a reference in apple documentation warning 
> that boolValue might return a non-YES/NO value from an NSNumber, I'd 
> have said that yes, we are entitled to insist on correct usage of 
> BOOL.

We are not talking about return values! I think we pretty much agree 
that a -(BOOL)boolValue *should* return YES or NO (I wouldn't go as far 
and claim that it must).

Cocoa reference says:
"+ (NSNumber *)numberWithBool:(BOOL)value
Creates and returns an NSNumber containing value, treating it as a BOOL"

Which doesn't help. But to end this ridiculous discussion I tried on 
Panther:

    NSLog(@"Hello, World!: %@", [NSNumber numberWithBool:5]);
gives
    2004-02-02 19:52:35.633 BoolTest[4187] Hello, World!: true

So, topic closed (if only for compatibility reasons) unless someone 
digs out some document explicitly stating that the input to NSNumber 
+numberWithBool: is required to be an exact YES or NO. (in that case we 
should file a bug report at Apple, ... ROTFL ;-)

I would again like to point out that if the intention was to limit BOOL 
to YES and NO, it would have been defined as
  typedef enum { YES, NO } BOOL;

But it wasn't defined that way to be compatible with C boolean 
expressions. The existence of YES and NO is a simple convenience so 
that people don't clutter when assigning constant values to a variable.

Helge
--
http://docs.opengroupware.org/Members/helge
OpenGroupware.org