NAME Hash::Normalize - Automatically normalize Unicode hash keys. VERSION Version 0.01 SYNOPSIS use Hash::Normalize qw; normalize my %hash, 'NFC'; $hash{café} = 'coffee'; # NFD, "cafe\x{301}" print $hash{café}; # NFD, "cafe\x{301}" # 'coffee' is printed print $hash{café}; # NFC, "caf\x{e9}" # 'coffee' is also printed DESCRIPTION This module provides an utility routine that augments a given Perl hash table so that its keys are automatically normalized following one of the Unicode normalization schemes. All the following actions on this hash will be made regardless of how the key used for the action is normalized. Since this module does not use the "tie" mechanism, normalized hashes are indistinguishable from regular hashes as far as Perl is concerned, but this module also provides "get_normalization" to identify them if necessary. FUNCTIONS "normalize" normalize %hash; normalize %hash, $mode; Applies the Unicode normalization scheme $mode onto %hash. $mode defaults to 'NFC' if omitted, and should match "/^(?:(?:nf)?k?|fc)[cd]$/i" otherwise. "normalize" will first try to forcefully normalize the existing keys in %hash to the new mode, but it will throw an exception if there are distinct keys that have the same normalization. All the keys subsequently used for fetches, stores, exists, deletes and list assignments are then first passed through the according normalization procedure. "keys %hash" will also return the list of normalized keys. "get_normalization" my $mode = get_normalization %hash; normalize %hash, $mode; Returns the current Unicode normalization scheme in use for %hash, or "undef" if it is a plain hash. NORMALIZED SYMBOL LOOKUPS Stashes (Perl symbol tables) are implemented as plain hashes, therefore one can use "normalize %Pkg::" on them to make sure that Unicode symbol lookups are made regardless of normalization. package Foo; BEGIN { require Hash::Normalize; # Enforce NFC normalization Hash::Normalize::normalize(%Foo::, 'NFC') } sub café { # NFD, "cafe\x{301}" return 'coffee' } sub coffee_nfc { café() # NFC, "cafe\x{e9}" } sub coffee_nfd { café() # NFD, "cafe\x{301}" } # Both coffee_nfc() and coffee_nfd() return 'coffee' CAVEATS Using a normalized hash is slightly slower than a plain hash, due to the normalization procedure and the overhead of magic. If a hash is initialized from a normalized hash by list assignment ("%new = %normalized"), then the normalization scheme will not be carried over to the new hash, although its keys will initially be normalized like the ones from the original hash. EXPORT The functions "normalize" and "get_normalization" are only exported on request by specifying their names in the module import list. DEPENDENCIES perl 5.10. Carp, Exporter (core since perl 5). Unicode::Normalize (core since perl 5.8). Variable::Magic 0.51. AUTHOR Vincent Pit, "", . You can contact me by mail or on "irc.perl.org" (vincent). BUGS Please report any bugs or feature requests to "bug-hash-normalize at rt.cpan.org", or through the web interface at . I will be notified, and then you'll automatically be notified of progress on your bug as I make changes. SUPPORT You can find documentation for this module with the perldoc command. perldoc Hash::Normalize COPYRIGHT & LICENSE Copyright 2017 Vincent Pit, all rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.