ruby - 有没有办法避免定义具有特定名称的方法？

Question

有没有办法避免(尝试时引发错误)定义具有特定名称的方法，例如 Foo#bar？ (一个用例是当 Foo#bar 已经定义时，我想避免该方法被覆盖，但这与问题无关。)我假设是这样的:

class Foo
  prohibit_definition :bar
end

...
# Later in some code

class Foo
  def bar
    ...
  end
end
# => Error: `Foo#bar' cannot be defined

Answer 1

class Class
  def method_added(method_name)
    raise "So sad, you can't add" if method_name == :bad
  end
end

class Foo
  def bad
    puts "Oh yeah!"
  end
end

#irb> RuntimeError: So sad, you can't add
#   from (irb):3:in `method_added'
#   from (irb):7