RE: interchanging variables the tough way

How about an unnamed sub (in the spirit of TMTOWTDI):

$a=1,$b=2,$c=3,$d=4,$e=5;

($a,$b,$c,$d,$e) = sub {push@_,shift;return@_}->($a,$b,$c,$d,$e);

print "\$a=$a,\$b=$b,\$c=$c,\$d=$d,\$e=$e\n";
[download]

It will probably perform worse than the other suggestions though...

/brother t0mas

Comment on RE: interchanging variables the tough way Download Code

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interchanging variables the tough way by agoth (Chaplain) on Aug 31, 2000 at 13:39 UTC
++ for amusement value, nice one :-)	[reply]
RE (tilly) 1 (possibilities): interchanging variables the tough way by tilly (Archbishop) on Aug 31, 2000 at 14:43 UTC
With a sub you can actually stop having to retype the list two times. Which is a nice feature: `$a=1,$b=2,$c=3,$d=4,$e=5; &rotate($a, $b, $c, $d, $e); print "\$a=$a,\$b=$b,\$c=$c,\$d=$d,\$e=$e\n"; sub rotate { my $temp = $_[0]; foreach (0..($#_ - 1)) { $_[$_] = $_[$_+1]; } $_[-1] = $temp; }` [download] OK, this is definitely slower, but you see the point.	[reply] [d/l]
RE: (tilly) 2 (possibilities): interchanging variables the tough way by tilly (Archbishop) on Aug 31, 2000 at 16:08 UTC
Looking at this bugs me. Manipulating your input arguments this way works, but the side-effects can surprise and amaze. I would not do this lightly. My overall feeling is that if you feel the need to rotate your data, you should have an array rather than a list of variables. Then you could `push @array, shift @array;` [download] much faster, without resorting to nasty side-effects. Generally when I see myself wanting to resort to "bad" techniques like side-effects, I take that as a danger sign and go looking for a more fundamental mistake in my code...	[reply] [d/l]