在Clojure中使用Spectre移除嵌套值 [英] Removing nested values with Specter in Clojure

问题描述

假设我有一个像这样的Clojure映射：

Suppose that I have a Clojure map like this:

(def mymap {:a [1 2 3] :b {:c [] :d [1 2 3]}})

我想删除一个函数-empties生成一个新映射，其中将删除（：b mymap）中具有空序列作为值的条目。因此（remove-empties mymap）将给出值：

I would like a function remove-empties that produces a new map in which entries from (:b mymap) that have an empty sequence as a value are removed. So (remove-empties mymap) would give the value:

{:a [1 2 3] :b {:d [1 2 3]}}

是否可以使用Spectre编写函数来实现此目的？ / p>

Is there a way to write a function to do this using Specter?

推荐答案

(update my-map :b (fn [b]
                    (apply dissoc b 
                           (map key (filter (comp empty? val) b)))))

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