Question

(require '[clojure.test.check.generators :as gen])

(def ACTIONS
  {:create-new-user #{}
   :edit-user #{:create-new-user}
   :create-new-board #{:create-new-user}
   :edit-board #{:create-new-board}
   :create-new-anonymous-comment #{:create-new-board}
   :create-new-signed-comment #{:create-new-board}
   :edit-comment-text #{:create-new-anonymous-comment :create-new-signed-comment}
   :edit-comment-text-and-flip-anonymity #{:create-new-anonymous-comment :create-new-signed-comment}
   :flip-anonymity #{:create-new-anonymous-comment :create-new-signed-comment}
   :vote-comment-up #{:create-new-anonymous-comment :create-new-signed-comment}
   :vote-comment-down #{:create-new-anonymous-comment :create-new-signed-comment}})

(def actions (-> ACTIONS keys vec gen/elements gen/vector))

(defn filter-actions-into-logical-order [as]
  (let [seen (atom #{})]
    (filter
     (fn [v]
       (let [required (get ACTIONS v)
             valid? (or (some? (some required @seen)) 
                        (and (empty? @seen) (= v :create-new-user)))]
         (when valid?
           (swap! seen conj v)
           true)))
     as)))

(def ordered-actions (gen/fmap #(-> % filter-actions-into-logical-order vec)  actions))

作为两个发电机的一个例子：

# (last (gen/sample actions 100))
[:edit-user :vote-comment-down :flip-anonymity :vote-comment-down :vote-comment-down :vote-comment-up :edit-user :create-new-anonymous-comment :edit-board :create-new-signed-comment :vote-comment-up :edit-comment-text-and-flip-anonymity :edit-user :create-new-signed-comment :edit-user :edit-user :vote-comment-down :edit-user :vote-comment-down :create-new-user :vote-comment-down :create-new-user :create-new-user :edit-comment-text-and-flip-anonymity :create-new-user :edit-comment-text-and-flip-anonymity :create-new-anonymous-comment :edit-comment-text :create-new-board :vote-comment-down :flip-anonymity :create-new-signed-comment :vote-comment-up :create-new-user :create-new-signed-comment :edit-user :create-new-user :create-new-board :vote-comment-down :create-new-board :create-new-board :create-new-board :edit-board :edit-comment-text-and-flip-anonymity :edit-user :edit-comment-text :create-new-signed-comment :vote-comment-up :edit-comment-text-and-flip-anonymity :flip-anonymity :create-new-anonymous-comment :create-new-anonymous-comment :edit-board :create-new-signed-comment :edit-comment-text-and-flip-anonymity :edit-board :vote-comment-up :edit-comment-text :create-new-board :edit-comment-text-and-flip-anonymity :create-new-board :vote-comment-down :edit-comment-text-and-flip-anonymity :vote-comment-up :create-new-user :vote-comment-up :edit-comment-text :edit-board :edit-comment-text-and-flip-anonymity :flip-anonymity :edit-board :create-new-anonymous-comment :flip-anonymity :create-new-signed-comment :edit-user :edit-comment-text-and-flip-anonymity :edit-comment-text :edit-comment-text :create-new-user :flip-anonymity :edit-user :vote-comment-up :edit-user :create-new-user :edit-comment-text :edit-comment-text :flip-anonymity :edit-comment-text :edit-board :flip-anonymity :edit-board :edit-comment-text :edit-user :create-new-user :flip-anonymity]


# (last (gen/sample ordered-actions 100))
[:create-new-user :edit-user :edit-user :create-new-board :edit-board :edit-user :create-new-anonymous-comment :edit-comment-text :edit-board :edit-user :edit-user :vote-comment-up :edit-comment-text :create-new-signed-comment :edit-comment-text :create-new-board :edit-comment-text :edit-comment-text :edit-comment-text :vote-comment-up :vote-comment-up :edit-board :edit-comment-text-and-flip-anonymity :create-new-signed-comment :create-new-anonymous-comment :create-new-signed-comment :edit-user :create-new-anonymous-comment :edit-board :create-new-board :create-new-anonymous-comment :create-new-board :flip-anonymity :create-new-anonymous-comment :edit-board :vote-comment-up :vote-comment-down :edit-board :edit-comment-text :edit-user :edit-comment-text :flip-anonymity :create-new-signed-comment :vote-comment-up :edit-comment-text-and-flip-anonymity :vote-comment-up :create-new-signed-comment :edit-comment-text :create-new-signed-comment :create-new-anonymous-comment :edit-board :create-new-anonymous-comment]

ACTIONS是一个映射，其中键是操作的名称，值是该操作的（基于OR）依赖项。例如，您必须先:create-new-user才能执行任何操作，您必须:create-new-board才能:edit-board，并且必须至少有:create-new-*-comment才能:edit-comment-text filter-actions-into-logical-order {1}}。

上面的代码似乎有效，但它很难看。 1）我不喜欢:create-new-user代码必须具有{{1}}的特定例外。 2）我不喜欢我基本上采用随机动作列表，并将其过滤掉，直到动作有意义。

我想知道其他人如何使用test.check生成这样的一系列操作？当然必须有一种方法只使用发电机吗？

Answer 1

使用gen/bind的递归生成器执行此操作并不困难（例如，首先生成操作列表的大小，然后使用gen/bind使用该大小的递归这样您就可以在每个步骤中执行先前生成的操作了。这种方法的一个重大缺点是gen/bind在收缩方面的效果相当差，因此您可能最终会采取几乎不会收缩的长序列动作。

我真的想为此提出更好的建议。

Answer 2

嗯，转换为filter-into-logical-order

后，reduce可能会变得更干净

(defn filter-into-logical-order [as]
  (last (reduce
         (fn [[seen accepted-as] action]
           (let[needed (get ACTIONS action)]
             (if (or (empty? needed) (some seen needed))
               [(conj seen action) (conj accepted-as action)]
               [seen accepted-as]))
           )
         [#{} []]
         as)))

但是我仍然为我提供了大约30％的空载体，它不是发电机。但我不确定记录的组合器是否真的支持你想要的东西。 gen/vector似乎不支持将构造向量传递给其内部生成器，因此它可以知道允许的值，这是您的需求所需的结构。

如何以约束顺序为一系列操作创建test.check生成器？

2 个答案: