For review: PEP 308 - If-then-else expression

[Roy Smith]

In article <b27d3p$gm$1 at slb9.atl.mindspring.net>,
 "Andrew Dalke" <adalke at mindspring.com> wrote:

> That's why I analyzed code from a language which already has
> an if/else ternary expression.  Eg, consider this example from Python's
> C implementation, in cellobject.c (first one I found, but I imagine
> there are plenty such examples)
> 
>            if (b->ob_ref == NULL)
>                    return 0;
>            return -1;
> 
> This could be written in C as
> 
>    return  b->ob_ref == NULL ? 1 : 0

Except that you managed to both reverse the sense of the comparison and 
the sign of the value returned if the comparison is false!  Not that I 
noticed that right away; it took me a few moments to work through 
exactly what you wrote did.  I'm not trying to pick on you, just point 
out that the longer form, written over three lines, is easier to 
understand.

It could have been written:

    return - (b->ob_ref != NULL);

but I'd slap anybody who tried to bring something like that to a code 
review :-)