traverse_sequences(
    \@seq1, \@seq2,
    {   MATCH => $callback_1,
        DISCARD_A => $callback_2,
        DISCARD_B => $callback_3,
    },
    undef,     # default key-gen
    $myArgument1,
    $myArgument2,
    $myArgument3,
);

$callback_1 = sub {…};
$callback_2 = sub {…};
$callback_3 = sub {…};

##</code><code>##

my $str1 = shift @_;
my $str2 = shift @_;