It looks like that filter does an exact comparison ignoring whitespace. To be more effective it would need to ignore things like variable renames and trivial tr

It looks like that filter does an exact comparison ignoring whitespace. To be more effective it would need to ignore things like variable renames and trivial transformations (for(;;) becoming while(true) or whatever). In other words we're getting into cheat-detection software territory, which sounds difficult to get right in general.