app/models/post.rb
class ::Post
@@public_posts_scope = method(:public_posts).clone
@@private_posts_scope = method(:private_posts).clone
scope :public_posts, -> { @@public_posts_scope.call.where("topics.archetype <> ?", Archetype.chat) }
scope :private_posts, -> { @@private_posts_scope.call.where("topics.archetype <> ?", Archetype.chat) }
end