foreach my $thing (@array) {
        process($thing);
        add_to_processed($thing);
}

sub process {
        my $thing = shift;
        next if boring($thing);
        ....
}

sub add_to_processed {
        my $thing = shift;
        last if too_many($thing);
        ....
}

##</code><code>##

for my $case ( @cases ) {
    my $is_interesting = eval { interesting($case) };
 
    print "$case had errors:$@" if $@;
    next unless $is_interesting;

    eval { process($case) };
    if ($@) {
       print "$case had errors:$@";
    }
}