Clojure嵌套映射 - 更改值 [英] Clojure nested map - change value

问题描述

不得不说我大约两个星期前开始学习Clojure，现在我从三天开始就遇到了问题。

我得到了一个这样的地图：

  {
：agent1 {：nameDoe：firstnameJohn：statea：time VZ：teamX} 
：agent2 {：nameDon：firstnameSilver：statea：timeVZ：teamX} 
：agent3 {：name Kim：firstnameTest：stateB：timeZZ：teamG} 
} 
  

$ b b

并需要将：teamX更改为：teamH。
我尝试过很多东西，例如 assoc ， update-in 等等，但没有什么工作。 / p>

我如何做我的东西？
非常感谢！

解决方案

assoc-in用于在路径指定的地图中替换或插入值

 （def m {：agent1 {：nameDoe：firstnameJohn：statea：timeVZ ：teamX} 
：agent2 {：nameDon：firstnameSilver：statea：timeVZ：teamX} 
： Kim：firstnameTest：stateB：timeZZ：teamG}}）
 
（assoc-in m [：agent1：team]H）
 
 {：agent1 {：statea，：teamH，：nameDoe，：firstnameJohn，：timeVZ}，
：agent2 {：state a，：teamX，：nameDon，：firstnameSilver，：timeVZ}，
：agent3 {：stateB，：teamG，：name Kim，：firstnameTest，：timeZZ}} 
  

想要更新所有团队X，无论具体路径，在树的所有递归级别，你可以使用clojure.walk的prewalk或postwalk函数结合自己的函数：

 （使用'clojure.walk）
（defn postwalk-mapentry 
 [smap nmap form] 
 x]（if（= smap x）nmap x））form））
 
（postwalk-mapentry [：teamX] [：teamT] m）
 
 {：agent1 {：statea，：teamT，：nameDoe，：firstnameJohn，：timeVZ}，
：agent2 {：state ：teamT，：nameDon，：firstnameSilver，：timeVZ}，
：agent3 {：stateB，：teamG，：nameKim ：firstnameTest，：timeZZ}} 
  

have to say I started learning Clojure about two weeks ago and now I'm stuck on a problem since three full days.

I got a map like this:

{
  :agent1 {:name "Doe" :firstname "John" :state "a" :time "VZ" :team "X"}
  :agent2 {:name "Don" :firstname "Silver" :state "a" :time "VZ" :team "X"}
  :agent3 {:name "Kim" :firstname "Test" :state "B" :time "ZZ" :team "G"}
}

and need to change :team "X" to :team "H". I tried with a lot of stuff like assoc, update-in etc. but nothing works.

How can I do my stuff? Thank you so much!

解决方案

assoc-in is used for replacing or inserting values in the map specified by path

(def m { :agent1 {:name "Doe" :firstname "John" :state "a" :time "VZ" :team "X"}
         :agent2 {:name "Don" :firstname "Silver" :state "a" :time "VZ" :team "X"}
         :agent3 {:name "Kim" :firstname "Test" :state "B" :time "ZZ" :team "G"}})

(assoc-in m [:agent1 :team] "H")

{:agent1 {:state "a", :team "H", :name "Doe", :firstname "John", :time "VZ"},
 :agent2 {:state "a", :team "X", :name "Don", :firstname "Silver", :time "VZ"},
 :agent3 {:state "B", :team "G", :name "Kim", :firstname "Test", :time "ZZ"}}

however, if you want to update ALL team "X"'s, regardless of specific path, over all recursive levels of the tree, you can use clojure.walk's prewalk or postwalk functions combined with a function of your own:

(use 'clojure.walk)
(defn postwalk-mapentry
    [smap nmap form]
(postwalk (fn [x] (if (= smap x) nmap x)) form))

(postwalk-mapentry [:team "X"] [:team "T"] m)

{:agent1 {:state "a", :team "T", :name "Doe", :firstname "John", :time "VZ"},
 :agent2 {:state "a", :team "T", :name "Don", :firstname "Silver", :time "VZ"},
 :agent3 {:state "B", :team "G", :name "Kim", :firstname "Test", :time "ZZ"}}

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