NAME
Hash::Normalize - Automatically normalize Unicode hash keys.
VERSION
Version 0.01
SYNOPSIS
use Hash::Normalize qw<normalize>;
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, "<perl at profvince.com>", <
http://www.profvince.com>.
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
<
http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Hash-Normalize>. 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.
