[Chicago-talk] Limiting a hash, or producing an interesting list

[Mike Pastore]

Jay,

After playing around with it for a bit, I think your way is best if you
want to keep separate %all and %interesting maps. But if you  don't mind
modifying the original list, here's an alternative method:

    my @all = qw/this that other some junk trash need/;
    my @interesting = qw/this that need/;

    my %search = map { $_ => 1 } @interesting;
    for(my $i = $#all; $i >= 0; $i--) {
        splice @all, $i, not exists $search{$all[$i]};
    }

Overall, I think your way is best.

--
Mike Pastore
mike at oobak.org

On Tue, 2003-11-25 at 07:17, Jay Strauss wrote:
> Hi,
> 
> I'm not sure how best to explain what I want to do.  the code below does
> what I want, but it seems needlessly complicated.  I figure there is
> probably a nice clean way to do this is less steps but I don't see it:
> 
> Essentially, I have a list of all the fields "@all", and I want to produce a
> list of only the fields I'm interested in, and their position in the
> original list
> 
> my @all = wq/this that other some junk trash need/;
> my %all;
> my @all{@all} = (0..$#all);
> 
> my @interesting = qw/this that need/;
> my %interesting;
> @interesting{@interesting} = delete @all{@interesting};
> 
> thanks
> Jay
> 
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