HoHoH Dynamicaly

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

Hi, I hava the following code.

foreach $key(sort {$a<=>$b} keys(%resultHoA)){
       @tmp=@{$resultHoA{$key}};#[@sorted_cols];
       $statushash{$tmp[0]}{$tmp[1]}{$tmp[2]}[0]='0';
    }
[download]

In the above code the keys ({$tmp[0]}{$tmp[1]}{$tmp[2]}) are three. How can I change this code so that the no of keys can match the element of the array?. ie. if only one elt then hash must be

$statushash{$tmp[0]}[0]='0',
[download]

if @tmp contains 2 elts hash mush be

$statushash{$tmp[0]}{$tmp[1]}[0]='0'
[download]

and so on. Can U help me out?. Thanks in Adv.

Comment on HoHoH Dynamicaly Select or Download Code

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Re: HoHoH Dynamicaly by brian_d_foy (Abbot) on Dec 06, 2006 at 06:31 UTC
The trick is to work from the inside-out. Define the lowest level, then add that to the next level. Inside the `foreach`, I can use `$hash` on both sides of the assignment because Perl will compute the right hand side first then assign that result to the left-hand side. `my @tmp = qw( a b c d ); my @keys = reverse @tmp; my $first_key = shift @keys; my $hash = { $first_key => [ 0 ] }; foreach my $key ( @keys ) { $hash = { $key => $hash }; } use Data::Dumper; print Dumper( $hash );` [download] Rael Dornfest asked me to do this for bloxsom, and I thought I had posted it somewhere but I can't find it now. You can make it simpler sometimes by putting the leaf value as the initial value for `$hash`, then letting the `foreach` construct all the levels of the hash. It's a bit cleaner, but harder to see the trick: `my @tmp = qw( a b c d ); my $hash = [0]; # not really a hash foreach my $key ( reverse @tmp ) { $hash = { $key => $hash }; } use Data::Dumper; print Dumper( $hash );` [download] -- brian d foy <brian@stonehenge.com> Subscribe to The Perl Review	[reply] [d/l] [select]
Re: HoHoH Dynamicaly by ikegami (Patriarch) on Dec 06, 2006 at 05:12 UTC
Data::Diver will do this for you: `DiveVal( \%statushash, @tmp, 0 ) = '0';` [download]	[reply] [d/l]
Re: HoHoH Dynamicaly by Roy Johnson (Monsignor) on Dec 06, 2006 at 18:16 UTC
merlyn wrote a nifty little sub to do this. Caution: Contents may have been coded under pressure.	[reply]
Re: HoHoH Dynamicaly by Anonymous Monk on Dec 06, 2006 at 12:04 UTC
`my $ref = \%statushash; $ref = $ref->{$_} for @tmp; $ref->[0] = '0';` [download]	[reply] [d/l]