[ruby-talk:03072] Re: FailureClass?

Aleksi Niemel<[e-mail]> writes:

>   /* is*-routines return boolean (that is 0 or 1), 
>      and we want to print "ok" if at least four of the tests passes */
>   if( isPerfect() + isBeautiful() + isWonderful() + 
>       isNotTooBad() + isEasy() + isOhInRuby() > 6-2 ){
>       printf("ok");
>   }

In C, non-zero is true, so you'd better be really sure of your
predicate routines for this to work!

> One can accomplish equivalent functionality with
> 
> if [isPerfect, isBeautiful, isWonderful, 
>     isNotTooBad, isEasy, isOhInRuby].filter{
>   |x| nil if x == true; x}.compact!.length <= 2
>   print "ok"
> end
> 
> But I'm sure someone else agrees it's quite a bit harder and uglier (while
> I'm not saying C-version isn't ugly :).

True, but this version

 if [isPerfect,   isBeautiful, isWonderful, 
     isNotTooBad, isEasy,      isOhInRuby].select{|x| x}.size <= 2
   puts "ok"
 end

Seems tidier than the C, and more flexible. It also honors the
language's definition of true and false, which the C version doesn't.



Dave