NAME Tie::Multidim - "tie"-like multidimensional data structures SYNOPSIS use Tie::Multidim; my $foo = new Tie::Multidim \%h, '%@%'; $foo->[2]{'die'}[4] = "isa"; DESCRIPTION This module implements multi-dimensional data structures on a hash. $foo->[2]{'die'}[4] gets "mapped" to $bar{"2;die;4"}, where the ';' is actually $SUBSEP ($;), and %bar is a hash you provide. It is particularly useful in two, not disjoint, situations: 1. the data space (matrix, if you prefer) is sparsely populated; 2. the hash into which the data is mapped is tied. This illustrates (1): my %matrix; # hash to store the data in. local $; = ' '; my $foo = new Tie::Multidim \%matrix, '@@'; # array-of-arrays. print $foo->[5432][9876]; # prints the value of $matrix{"5432 9876"}. This illustrates (2): my %matrix; tie %matrix, 'Matrix'; # some hashtie-able class. local $; = ";"; # gets remembered by the object. my $foo = new Tie::Multidim \%matrix, '%@%'; # 3-level structure: hash of arrays of hashes. $foo->{'human'}[666]{'beast'} = "value"; # causes a call to sub Matrix::STORE { my( $self, $index, $value ) = @_; my( $x, $y, $z ) = split $;, $index; # with $x = 'human', $y = 666, and $z = 'beast'. } METHODS new This is the constructor. The first argument is a hash-reference. This hash will be used by the Tie::Multidim object to actually store the data. The reference can be to an anonymous hash, to a normal hash, or to a tied hash. Tie::Multidim doesn't care, as long as it supports the normal hash get and set operations (STORE and FETCH methods, in TIEHASH terminology). The second argument is a string containing '@' and '%' characters (a al function prototypes). The multidimensional data structure will be constructed to have as many dimensions as there are characters in this string; and each dimension will be of the type indicated by the character. '@%' is an array of hashes; '%@' is a hash of arrays; and so on. storage This returns the same hash reference that was passed as the first argument to the constructor. Not exactly a method, it must be called as a package function, and passed the multidim reference. $foo = new Tie::Multidim, \%h, '@@'; $hashref = Tie::Multidim::storage( $foo ); # same effect as: $hashref = \%h; AUTHOR (John Porter) COPYRIGHT This module is free software; you may redistribute it and/or modify it under the same terms as Perl itself.