my @phrase_parts = split /(\$(?:\(\w+\)|\w+))/, $phrase;
foreach my $part ( @phrase_parts ) {
       $part =~ s{ \$    (\w+)    }{$variables->{$1}}xms
    || $part =~ s{ \$ \( (\w+) \) }{$variables->{$1}}xms;
}
$phrase = join '', @phrase_parts;