Yes, a what you described would work just fine, but I am wondering if just a
loop control variable that can be possibly set at the begining of the loop
which would not necessarily exit the loop, but rather yield kind of a true
or false.
for ($a, $b, $c) (@A, @B, @C) : @B ### This would assign a true|false 1|0
to control variable when it reaches this loop number.
But I guess incrementing/decrementing the control variable would work just
fine, since it can later be accessed in the loop and to the shortest array.
It can be easily done with a few lines of code without any special vars,
etc..., just by incrementing a counter, while comparing to the shortes
array, but I'm wondering if a control variable would yield other benefits
and if nothing else decrease the amount of written code.
Ilya
-----Original Message-----
From: David L. Nicol
To: Sterin, Ilya
Cc: Perl 6 Language
Sent: 07/24/2001 6:03 PM
Subject: Re: array/hash manipulation [was :what's with 'with'?]
"Sterin, Ilya" wrote:
> But now I am trying to figure out, if you are not comparing elements
of the
> array and for example if you need to loop through 3 arrays at the same
time,
> but you need to know, whithin the loop, when the shortest array's last
> element is reached, how would that be accomplished within the loop if
the
> array would just be reset and continue until the longest end is
reached?
>
> Ilya
You have three generator functions that each produce one element at a
time,
and they, and a fourth, flag-checking function (possibly the loop
control variable itself) all have access to a flag that is decremented
by each generator when it starts looping. For instance, rewrite
for ($c,$d,$e) (@A, @B, @C) { ... };
into something very similar if not exactly like this:
{
my $arrays_index=0;
while ($arrays_index < @A
and $arrays_index < @B
and $arrays_index < @C){
local (*c, *d, *e) =
($A[$arrays_index % @A],
$B[$arrays_index % @B],
$C[$arrays_index % @C]);
...
$arrays_index+=1;
};
};
a workaround of some kind would be required for empty arrays, or
maybe having it die on an empty array is fine.
--
David Nicol 816.235.1187
"Hush!" said the little boy's mother. But it was too late. The
emperor's agents had already heard his meek, innocent question and
were rushing through the crowd. The emperor's agents took the boy
away and he was never, ever, seen or heard from again.
