Re: [Pyobjc-dev] caution with BOOL parameters

[Ronald O. <ous...@ci...>]

On Saturday, Mar 1, 2003, at 20:56 Europe/Amsterdam, Bob Pasker wrote:

> this begs the question: in pyobjc, is the 'c' in a method signature
> ONLY used for BOOL types?
Nope, 'c' is used for 'char', hence the _C_CHR ;-) ;-).

> if so, then maybe the right answer is to
> put the test in obj_support.m, ie, change
>
> 	case _C_CHR: case _C_SHT:
> 		return pythonify_c_value(intType, datum);
>
> to something like:
>
> 	case _C_SHT:
> 		return pythonify_c_value(intType, datum);
> 	case _C_CHR:
> 		return (pythonify_c_value(intType, datum) != 0);
>
> in general, the programmer should return an expression that evaluates 
> to
> 0 or 1 for objc bool parameters. but most languages without a true
> boolean type permit integer types to be used as boolean
> expression without a boolean operator operators. python falls into
> this category, and using the bridge should not require a special
> idiom for booleans ("always return/pass a boolean expression, not
> an int").

I'm afraid this is one of the places where the bridge cannot be 
completely transparent. In Python you can use any object as a boolean 
(most are evaluated as true, some are false), but with PyObjC you'll 
have to use small integers.

Let's hope someone sees this as his/her cue to come up with a very 
clever solution.

Ronald