multi read-csv($filename, $dict where { $dict }) {
    my @lines = $filename.IO.lines.list;
    my $hdr := split ',', @lines[0].cache;

    sub parse_row($row) {
        my $parts := split ',', $row;
        my %row_dict;
        for (zip $hdr, $parts) { %row_dict{$_[0]} = $_[1] };
        return %row_dict;
    }

    map &parse_row, @lines[1..*];
}

multi read-csv($filename, $dict where { !$dict }){
    map { split(',', $_) }, $filename.IO.lines
}