什么是习语Clojure“去除”从列表中的多个单个实例？ [英] What is idiomatic Clojure to "remove" a single instance from many in a list?

问题描述

我有一个列表，其中可能包含比较相等的元素。我想要一个类似的列表，但删除一个元素。所以从（：a：b：c：b：d）我想要能够删除只是一个：b获得（：a：c：b：d） p>

上下文是卡牌游戏中的一手牌，其中有两副标准牌在玩，所以可能有重复的牌，但是一次只能玩一张。

我有工作代码，见下文。在Clojure中有更多惯用的方法吗？

 （defn remove-one [c left right] 
 if（= right（））
 left 
（if（= c（first right））
（concat（reverse left）（rest right））
 （删除一个c（）卡）））
 
（defn remove-card [c cards] 
 b  

这是我前一段时间的Scala答案：什么是习语Scala方式，一个来自不可变列表的元素？

解决方案

如何：

 （let [[nm]（split-with（partial not =：b）[：a：b：c：b：d]）]（concat n ）））
  

它将列表拆分为：b，然后删除：b， 。

I have a list, which may contain elements that will compare as equal. I would like a similar list, but with one element removed. So from (:a :b :c :b :d) I would like to be able to "remove" just one :b to get (:a :c :b :d).

The context is a hand in a card game where two decks of standard cards are in play, so there may be duplicate cards but still played one at a time.

I have working code, see below. Are there more idiomatic ways to do this in Clojure?

(defn remove-one [c left right]
  (if (= right ())
    left
    (if (= c (first right))
      (concat (reverse left) (rest right))
      (remove-one c (cons (first right) left) (rest right)))))

(defn remove-card [c cards]
  (remove-one c () cards))

Here are the Scala answers I got a while ago: What is an idiomatic Scala way to "remove" one element from an immutable List?

解决方案

How about:

(let [[n m] (split-with (partial not= :b) [:a :b :c :b :d])] (concat n (rest m)))

Which splits the list at :b and then removes the :b and concats the two lists.

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