On Mon, Oct 29, 2001 at 05:26:39PM +0100, allan wrote:
> > Have you considered using a hash of arrays instead?
> >
> > push @{$files{'.pl'}}, ':folder_one:byte.pl';
> > push @{$files{'.pl'}}, ':folder_one:byte.pl';
> > push @{$files{'.gif'}}, ':folder_one:some.gif';
> >
> > etc.
> >
> > Ronald
>
> actually yes, though with this syntax:
>
> $hash_of_file_extensions{".pl"} = [":folder_one:byte.pl", 1];
That won't work, because you're overwriting the array with each assignment.
> but that didnt help much, because i still could not maintain the insert
> order. it seems the only "nonmodular" way is by a push.
> i have given up with the tie::Hash module as i could not get it to
> maintain the order of the inner hash, the outher hash was no problem.
You would have to tie each inner hash as a Tie::IxHash as well.
> so my current code (which is unfortuantely slow as it is a pretty large
> filesystem) looks something like this (i dont have it right here):
>
> $hash_of_file_extensions{$extension} = $level; # this is just to grab
> each extension only once, i dont actually use the level variable
> push(@somearray, $extension, $file);
>
>
> # then some time consuming stuff like this:
>
> foreach $key (sort(keys % hash_of_file_extensions)) {
> print "$hash_of_file_extensions\n";
> for ($i = 0; $i <= $#somearray; i++) {
> if ($somearray[$i] eq $key) {
> print $somearray[$i+1] \n";
> }
> }
> }
This way you've lost the separation by extension, so you have to search
through the entire list of files for each extension. Very inefficient.
Here's how I would construct and print the data structure. I don't know
how you're getting the files, so I've just written in a placeholder
function called get_next_file(). You'll forgive me if I use a shorter
variable name that 'hash_of_file_extensions'.
while (my $file = get_next_file()) {
my $extension = '';
$extension = $1 if $file =~ /(\.[^.]+)\z/;
push @{ $files{$extension} }, $file;
}
foreach my $extension (%files) {
print "$extension\n";
foreach my $file (@{ $files{$extension} }) {
print " $file\n";
}
}
The whole data structure, which is a hash of arrays, will look something
like this:
{
'.pl' => [ 'foo.pl', 'bar.pl' ],
'.gif' => [ 'me.gif', 'you.gif' ],
}
Ronald
