Re: TRUE

On Wed, Jan 21, 2004 at 06:43:26PM +0200, Gaal Yahas wrote:
> On Wed, Jan 21, 2004 at 11:09:29AM -0500, Andrew Pimlott wrote:
> >     use constant FALSE => !TRUE;
> >     use constant TRUE => !FALSE;
> 
> I start off all my programs with use strict :-)

Wimp.  :-)

> But more to the point, how do you use your TRUE and FALSE? Suppose you
> want to test the return value of this sub:
> 
> sub returns_a_true_value { 8.2 }
> 
> Would you do "if (returns_a_true_value() eq TRUE)"? "== TRUE"?

Aieee!

> Neither would work, and you can just do "if (returns_a_true_value())"
> directly anyway.

Of course, even if it weren't broken, "eq TRUE" is logically
redundant and indicates the programmer was asleep, drunk, or
clueless.  (Not that I haven't publically posted code with this
shameful wart.  I couldn't look another programmer in the eyes for
weeks!)

The constants do improve code where it otherwise wouldn't be clear
to the reader whether 1 was an integer or a boolean.  But such code
can sometimes be improved even more by defining a specific constant
for each use.  Say a function takes a couple flags, one indicating
whether it should output verbose message, another whether it should
stop on the first error.  If you write

    foo($bar, $baz, 0, 1);

you might forget what they mean.  If you write

    foo($bar, $baz, !VERBOSE, STOP_ON_ERROR);

it's obvious.

Andrew