here a possible patch to do this. It introduces a call to a new routine maybe_parens_lhs_arrow() into the return statement of elem().

Complex LHS-> is determined by not starting with a sigil or paren.

sub elem {
    my $self = shift;
    my ($op, $cx, $left, $right, $padname) = @_;
    my($array, $idx) = ($op->first, $op->first->sibling);

    $idx = $self->elem_or_slice_single_index($idx);

    unless ($array->name eq $padname) { # Maybe this has been fixed   
+ 
    $array = $array->first; # skip rv2av (or ex-rv2av in _53+)
    }
    if (my $array_name=$self->elem_or_slice_array_name
        ($array, $left, $padname, 1)) {
    return "\$" . $array_name . $left . $idx . $right;
    } else {
    # $x[20][3]{hi} or expr->[20]
    my $arrow = is_subscriptable($array) ? "" : "->";
    return maybe_parens_lhs_arrow($self->deparse($array, 24), $arrow)
      . $left . $idx . $right;
    }
}

sub maybe_parens_lhs_arrow {
    my ($lhs, $arrow)   = @_;
    return "($lhs)$arrow"
      if ($arrow eq "->" and $lhs !~ /^[$@%&(*]/);
    return "$lhs$arrow";
}
[download]

Looks like a weird hack ... much like most of B::Deparse ! :)

That's teh result then:

$ perl -I. -MO=Deparse -e '(do $foo)->{$bar}' 
(do($foo))->{$bar};
-e syntax OK

$ perl -I. -MO=Deparse -e '$foo->{$bar}' 
$$foo{$bar};
-e syntax OK
[download]