Hash::WithDefaults - class for hashes with key-casing requirements supporting defaults
version 0.04
use Hash::WithDefaults; %main = ( ... ); tie %h1, 'Hash::WithDefaults', {...}; tied(%h1)->AddDefault(\%main); tie %h2, 'Hash::WithDefaults', {...}; tied(%h2)->AddDefault(\%main); # now if you use $h1{$key}, the value is looked up first # in %h1, then in %main.
This module implements hashes that support "defaults". That is you may specify several more hashes in which the data will be looked up in case it is not found in the current hash.
tie %hash, 'Hash::WithDefault', [$case_option], [\%values]; tie %hash, 'Hash::WithDefault', [$case_option], [%values];
The optional $case_option may be one of these values:
Sensitive - the hash will be case sensitive Tolower - the hash will be case sensitive, all keys are made lowercase Toupper - the hash will be case sensitive, all keys are made uppercase Preserve - the hash will be case insensitive, the case is preserved Lower - the hash will be case insensitive, all keys are made lowercase Upper - the hash will be case insensitive, all keys are made uppercase
If you pass a hash reference or an even list of keys and values to the tie() function, those keys and values will be COPIED to the resulting magical hash!
After you tie() the hash, you use it just like any other hash.
tied(%hash)->AddDefault(\%defaults);
This instructs the object to include the %defaults in the search for values. After this the value will be looked up first in %hash itself and then in %defaults.
You may keep modifying the %defaults and your changes WILL be visible through %hash!
You may add as many defaults to one Hash::WithDefaults object as you like.
$defaults = tied(%hash)->GetDefaults(); push @$defaults, \%another_default;
Returns a reference to the array that stores the defaults. You may delete or insert hash references into the array, but make sure you NEVER EVER insert anything else than a hash reference into the array!
use Config::IniHash; $config = ReadIni $inifile, withdefaults => 1, insensitive => 'preserve'; if (exists $config->{':default'}) { my $default = $config->{':default'}; foreach my $section (keys %$config) { next if $section =~ /^:/; tied(%{$config->{$section}})->AddDefault($default) } }
And now all normal sections will get the default values from [:default] section ;-)
Jan Krynicky <Jenda@Krynicky.cz> http://Jenda.Krynicky.cz
Copyright (c) 2002 Jan Krynicky <Jenda@Krynicky.cz>. All rights reserved.
This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
To install Hash::WithDefaults, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Hash::WithDefaults
CPAN shell
perl -MCPAN -e shell install Hash::WithDefaults
For more information on module installation, please visit the detailed CPAN module installation guide.