sub onefoo {
 my ($reasonably_named_sub, @params) = @_;
 whatever;
 for my $foo (tweaked @params) {
  $reasonably_named_sub->($foo);
 }
}

sub multifoo {
 my ($toDo, $filter, @params) = @_;
 whatever;
 for my $foo (grep $filter->(), tweaked @params) {
  $toDo->($foo);
 }
}