Re: Should loops return a value?

[Ville Jungman]

From: "John W. Krahn" <[EMAIL PROTECTED]>
You don't need a do block, the conditional operator can handle it.
@udat{ 'x', 'y' } = $subs->anna_tilavuus( $x + $lisax, $y + $lisay, $z )
< 100
                  ? do { $subs->paivita( $x ); ( $lisax, $lisay ) }
                  : $subs->anna_tilavuus( $x, $y + $lisay, $z ) < 100
                  ? ( undef, $lisay )
                  : ();
This is one of the main things i'd like to discuss and improve with these 
constructs - the readibility.

Now we have to use conditional operators every now and then but they suffer 
from being one of the least readable solutions available. Also there might 
be need of big alterations in code if the programmer suddenly realizes she 
wants to get a value out from a construct - like Your example proves (and 
this was a short one).

If everything was perfect with this, she just adds her '@variables=' before 
a construct and no additional alterations must be made to code. Like i wrote 
in another mail, the 'do' made exactly what i'm searching for - if the 'do' 
could be omitted (and sadly only with if-command, i suppose).

ville jungman, 2 laureston crescent, tower, blarney, cork, ireland
tel. + 353 - 21 - 451 6847, http://www.kolumbus.fi/vilmak
usko Herraan Jeesukseen, niin sinä pelastut. (apt. 16:31)




From: "John W. Krahn" <[EMAIL PROTECTED]>
To: [EMAIL PROTECTED]
Subject: Re: Should loops return a value?
Date: Mon, 29 Sep 2003 14:56:42 -0700
Steve Grazzini wrote:
>
> On Mon, Sep 29, 2003 at 11:04:46PM +0300, Ville Jungman wrote:
> > This is real example from what i was doing yesterday:
> >   if($subs->anna_tilavuus($x+$lisax,$y+$lisay,$z) < 100){
> >      $subs->paivita($x);
> >      $udat{x}=$lisax;
> >      $udat{y}=$lisay;
> >   }elsif($subs->anna_tilavuus($x,$y+$lisay,$z) < 100){
> >      $udat{y}=$lisay;
> >   }
> >
> > If using return values, this could be wrote as:
> >   ($udat{x},$udat{y})=
> >      if($subs->anna_tilavuus($x+$lisax,$y+$lisay,$z) < 100){
> >         $subs->paivita($x);
> >         retlast($lisax,$lisay)
> >      }elsif($subs->anna_tilavuus($x,$y+$lisay,$z) < 100){
> >         retlast(undef,$lisay);
> >      }
> >   ;
>
> You can do this already with "do" blocks.
>
>   my $condition = 1;
>
>   ($x, $y) = do {
>     if ($condition) { 42, 43 }
>     else            { 44, 45 }
>   };
You don't need a do block, the conditional operator can handle it.

@udat{ 'x', 'y' } = $subs->anna_tilavuus( $x + $lisax, $y + $lisay, $z )
< 100
                  ? do { $subs->paivita( $x ); ( $lisax, $lisay ) }
                  : $subs->anna_tilavuus( $x, $y + $lisay, $z ) < 100
                  ? ( undef, $lisay )
                  : ();
John
--
use Perl;
program
fulfillment
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