It still doesn't work though. The error message complains about not finding $nfd_letter in the hash…

Hmm. Very odd. There is no variable named $nfd_letter in your script.

This complete, self-contained, pared-down script…

#!perl

use strict;
use warnings;
use charnames qw( :full );
use Unicode::Normalize;

binmode STDOUT, ':encoding(UTF-8)';

# Lookup table of IPA properties by IPA symbol
my %properties_by = (
    d   => [ qw( 0 0 ) ],
    a   => [ qw( 0 1 ) ],
    NFD("\N{LATIN SMALL LETTER ALPHA}\N{COMBINING TILDE}")
        => [ qw( 1 0 ) ],
    s   => [ qw( 1 1 ) ],
);

# List of IPA phonemes
my @phonemes = (
    "das",
    "d\N{LATIN SMALL LETTER ALPHA}\N{COMBINING TILDE}s"
);

# For each IPA phoneme...
for my $phoneme (map { NFD($_) } @phonemes) {
    # ...examine each IPA symbol in it...
    for my $symbol ($phoneme =~ m/(\X)/g) {
        # ...and look up each symbol's IPA properties...
        my $properties = join ", ", @{ $properties_by{$symbol} };
        print "$phoneme\t$symbol\t$properties\n";
    }
}

exit 0;

[download]

…produces this output…

das	d	0, 0
das	a	0, 1
das	s	1, 1
dɑ̃s	d	0, 0
dɑ̃s	ɑ̃	1, 0
dɑ̃s	s	1, 1

By the way, there is no precomposed Unicode character that is the Latin small letter alpha with a tilde. So all the Unicode normalizations of "\N{LATIN SMALL LETTER ALPHA}\N{COMBINING TILDE}" are exactly the same—and exactly that.

In reply to Re^3: Unicode combining characters as hash keys? by Jim
in thread Unicode combining characters as hash keys? by Anonymous Monk

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