有没有办法在Perl中使用"常量"作为哈希键？

my $greeting = "Hello, World!";
my %favorite_numbers = (
    3 => 'three',
    7 => 'seven',   # 在这里将常量名作为哈希键
);

print "My favorite numbers are: ", Dumper %favorite_numbers;  # 输出：My favorite numbers are: $VAR1 = bless(\%favorite_numbers, 'HASH');

print constant("GREETING")."\n";        # 在同一常量后添加常量修饰符
print constant("GREETING")."\n";        
print "GREETING = ", constant("GREETING"),"\n"; # 在同一变量前加上常量修饰符

my %age_of_students = ( 
'grade 5' => 10,    # 用 'name' => 10 的方式定义学生年龄
);

my ($name_key, $age_key) = map {
    constant($_ => 2)
} qw(name age);