sub make_dequote_rx {
    my @char = map quotemeta, @_;
    my $chars = join '', @char;
    my $rx = join(
        ' | ',
        map(qq[$_ (?: \\\\ . | $_$_ | [^$_] ) + $_], @char),
        qq[(?: \\\\ . | [^$chars] ) +],
    );
    return qr/\G ( $rx )/x;
}

my $dequote = make_dequote_rx qw(' ");