Hash::Util::Set and Hash::Util::Join

A collection of utilities for set operations and SQL-like joins on Perl hashes.

Modules

Hash::Util::Set - Set Operations on Hash Keys

Provides set operations on hash keys.

Set Operations:

• keys_union - Keys in either hash (A ∪ B)
• keys_intersection - Keys in both hashes (A ∩ B)
• keys_difference - Keys in first but not second (A \ B)
• keys_symmetric_difference - Keys in either but not both (A △ B)
• keys_partition - Split into three sets: only A, both, only B

Set Predicates:

• keys_disjoint - No common keys?
• keys_equal - Same keys?
• keys_subset - A ⊆ B?
• keys_proper_subset - A ⊂ B (strict)?
• keys_superset - A ⊇ B?
• keys_proper_superset - A ⊃ B (strict)?

Membership Tests:

• keys_any - At least one key exists?
• keys_all - All keys exist?
• keys_none - No keys exist?

Hash::Util::Join - SQL-like Join Operations

Provides SQL-like join operations for combining two hashes based on their keys.

Join Operations:

• hash_inner_join - Keys in both hashes
• hash_left_join - All keys from left hash
• hash_right_join - All keys from right hash
• hash_outer_join - All keys from both hashes
• hash_left_anti_join - Keys only in left hash
• hash_right_anti_join - Keys only in right hash
• hash_full_anti_join - Keys in either but not both

Installation

cpanm Hash::Util::Set

Or manually:

perl Makefile.PL
make
make test
make install

Performance

Both modules automatically use XS implementations when available, falling back to pure Perl otherwise for maximum compatibility and performance.

Author

Christian Hansen chansen@cpan.org

Copyright and License

Copyright (C) 2026 Christian Hansen

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.