p5-Tie-Hash-TwoWay

Two-way mapping between disjoint sets in Perl

Tie::Hash::TwoWay will take a list of one-way associations and transparently create their reverse. For instance, say you have a list of machines, and a list of classes that each machine belongs to. Tie::Hash::TwoWay will take the machines, one by one, with an associated array reference of class names, and build the reverse mapping of classes to machines. All the mappings are stored as hashes. You can access the secondary mappings as if they were hash keys in their own right.