using Hash::Case and Storable together

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

I'm using the Storable module to save and load a hash. I also want to use the Hash::Case::Lower module to make my hash case insensitive. I can't figure out how to tie a hashref to the Hash::Case::Lower module and load data into it with Storable. I tried something like:

use Hash::Case::Lower;
use Storable;

tie my(%realhash), 'Hash::Case::Lower';
my $hashref = \%realhash;
$hashref = retrieve('somefile');
[download]

This causes $hashref to be assigned to the anonymous hash returned from retrieve() so that it no longer points to the tied hash. It is then no longer case insensitive. How can I make this work?

Comment on using Hash::Case and Storable together Download Code

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Re: using Hash::Case and Storable together by tkil (Monk) on Apr 26, 2004 at 07:53 UTC
Without testing either of these, I suspect that you have two options: (1) iterate through the retrieved hash, inserting key/value pairs into a newly-created Hash::Case::Lower object; or (2) go behind the back of Hash::Case::Lower to both dump out the hash, and load it back in. The former is straightforward, and probably looks something like this: `tie my(%lc_hash), 'Hash::Case::Lower'; { my $href = retrieve( ... ); while ( my ( $k, $v ) = each %$href ) { $lc_hash{$k} = $v; } }` [download] Although, if you're going through the whole thing anyway, there's no problem in applying `lc` to all the values manually. Might be faster... To go behind its back, you will want to save it directly; the only fancy footwork should be a `bless` when you read it back in. (This might not even be necessary — I don't know how clever `Storable` is, really.) `# writing it out store( \%lc_hash, ... ); # reading it in my $lc_href = retrieve( ... ); bless $lc_href, 'Hash::Case::Lower';` [download] All the above is untested, but hopefully it will give you some ideas to play with! :)	[reply] [d/l] [select]
Re: using Hash::Case and Storable together by eserte (Deacon) on Apr 26, 2004 at 12:26 UTC
Try to store and retrieve the object behind the tied hash. I.e.: `store(tied(%realhash), "file");` After retrieving the object, use the Tie::Restore module to get the tied hash again.	[reply] [d/l]
Re: Re: using Hash::Case and Storable together by agaffney (Beadle) on May 02, 2004 at 05:33 UTC
I ended up taking the easy way out and copying the entire structure with a 'foreach(keys %retrievedhash)' or something similar to the tied hash. Thanks for the suggestions, though.	[reply]