idioms.rb

class UserSession
  def viewable_posts
    # By using Post.scoped({}) rather than Post.all, you get a named scope proxy back,
    # meaning that you can chain other scopes onto it
    # and that the query is not executed until necessary.
    admin? ? Post.scoped({}) : Post.published
  end
end

class User
  def pastor?
    roles.any? { |r| r.title.include?('Pastor') }
  end
end

User.all.each do |user|
    # do something with “user”
end

# Greedy vs. non-greedy reg exp
i = 'acdbcdb'
i.match(/a.+b/)[0]  # greedy, yields “acdbcdb”
i.match(/a.+?b/)[0] # non-greedy, yields “acdb”