Ruby on rails 3.1 如何在haml视图中查找和循环数组的子集？

以下是我的模型和控制器：

class FaqCategory < ActiveRecord::Base
  has_many :faqs, dependent: :restrict, inverse_of: :faq_category
  validates :title, :presence=>true, uniqueness: {scope: :ancestry}


end


class Faq < ActiveRecord::Base
  belongs_to :faq_category, inverse_of: :faqs

  validates :question, :presence=>true
  validates :answer, :presence=>true

end

class HelpController < ApplicationController
  def faqs
    @faq_categories=FaqCategory.roots.order(:title)
    @faqs=Faq.all();
  end
end

我发现了这个错误（我是haml和rails的新手，可能缺少一些简单的东西）：

---

12：语法错误，意外的关键字\u sure，期望$end

嵌套有点奇怪。试试这个：

.unibody
    .content
        .inner-content
            - @faq_categories.each do |cat|
                = cat.title
                - @faqs.find_all{|faq| faq.faq_category==cat}.each do |thisfaq|
                    = thisfaq.question

---

非常感谢…需要一点时间来适应缩进的重要性。

.unibody
    .content
        .inner-content
            - @faq_categories.each do |cat|
                = cat.title
                - @faqs.find_all{|faq| faq.faq_category==cat}.each do |thisfaq|
                    = thisfaq.question