At 2004-11-02T11:26:32+1300, Alasdair Tennant wrote:
> OK, OK! It's a free-for-all! I had been holding back, BUT Tcl must
> have the neatest function for stepping through lists:-
> foreach {a b} {1 2 3 4 5 6} { add your code here, using $a and $b }
That's nice and simple. Just for the sake of it, here's some Perl stuff.
# A fairly simple way (C-like):
@ls = (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16);
while ($i <= $#ls) {
$a = $ls[$i++];
$b = $ls[$i++];
print "$a,$b\n";
}
# If you don't mind modifying the list:
@ls = qw(1 2 3 4 5 6);
while(($a, $b) = splice(@ls, 0, 2)) {
print "$a,$b\n";
}
# If you are bored and want to be fancy, use closures:
sub pairList (\@) {
$i = 0;
@a = @{$_[0]};
sub {
$i >= @a ? () : ($a[$i++], $a[$i++]);
}
}
@array = (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16);
$ls = pairList(@array);
while (($a, $b) = $ls->()) {
print "$a,$b\n";
}
And, being Perl, there are even more ways to achieve the same thing.
> Now somebody out there will do it in 5 obscure characters using Perl!
My implementation using closures is a little obscure, but that's because
I wrote it that way deliberately. It's easy to write obscure code in
any language. If you can be terse at the same time, you might as well.
;-)
Cheers,
-mjg
--
Matthew Gregan |/
/| [EMAIL PROTECTED]
