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

[Pascal J . Bourguignon]

David Ayers writes:
> Due to the standard C conversion rules, which may truncate the higher 
> order bytes, code must insure to explicitly convert any C truth values 
> into the valid BOOL values if either YES or NO.

No. Code must  insure to explicitly convert any C  scalar value into a
truth value, in order to be able to generate a valid BOOL value.

int a_value=4*256;
unsigned char  random_value = a_value;      /* THIS IS NOT A TRUTH VALUE!!! */
unsigned char  my_boolean   = (a_value!=0); /* must be explicit! */



> I'd say uninformed rather than careless, but maybe some sane C 
> programmer can offer a patch to our coding conventions to educate us 
> carelessly insane ObjC developers, by correctly and clearly stating and 
> demonstrating the issue.

void PleaseWrite(bool isBetter,void* pointer,int value);
{if((!isBetter)&&(pointer!=NULL)||(value==0)){ print("Right!\n");}}
int  value;
bool isCorrect=(value!=0);
value=isCorrect?1:0;


> I'd appreciate if we could get back to the discussion on whether we 
> should have a public macro to warn/assert about the correct values of 
> BOOL parameters and return values, so that other carelessly insane 
> developers may be educated.
> 
> I have no objections to stick with isYES(), but maybe a simple 
> is()/_is() may be less bulky than my previous alternatives and won't be 
> as hard to parse in comparisons involving NO.  I'd be in favor of 
> emitting a warning and "BOOLifying*" by default and possibly raising 
> with NDEBUG defined (i.e. when compiled with debug=yes).  If some think 
> this is too harsh because there are too many carelessly insane 
> developers that have produced legacy code that doesn't take care to 
> convert, I'd be fine with only emitting warnings.

> * comparing with "!= NO" and returning the result.

Perhaps it could be enough to check BOOL parameter input into the API.

-- 
__Pascal_Bourguignon__                     http://www.informatimago.com/
There is no worse tyranny than to force a man to pay for what he doesn't
want merely because you think it would be good for him.--Robert Heinlein
http://www.theadvocates.org/