# build the dependency map for active children
  $child{$_} ||= $parent{$_} for grep $_->active, $self->children;

##</code><code>##

  warn "Deleting removed script '$_'\n" for map $_->name, @deleted;

##</code><code>##

  for my $hidden (grep !$_->visible, @objects) {
    ...
  }

##</code><code>##

  # build the dependency map for active children
  $_->active and $child{$_} ||= $parent{$_} for $self->children;
  # (My brain doesn't grok 'condition and action' as fluently as
  # 'action if condition', but handles 'grep' fine.)

  warn "Deleting removed script '@{[ $_->name ]}'\n" for @deleted;
  # hmm, a minor difference, but @{[ ...]} is just too much punctuation

  for my $object (@objects) {
    next if $object->visible;
    # below here '$object' is less informative
    ...
  }

  for my $hidden (@objects) {
    # '$hidden' is a lie here
    next if $hidden->visible;
    ...
  }