怎么都掉!以及在这里工作的 mmap 函数?

how are swap! and the mmap function working here?

这是 Reagent project 的片段。查看 complete-allclear-done,我明白重点是换出修改后的地图。我不明白这是怎么做到的。 mmap 的定义调用了 3 个参数 — 而 complete-all 似乎用两个参数调用它,即 map#(assoc-in % [1 :done] v)clear-done 调用 remove#(get-in % [1 :done])。我尝试使用 repl 进行实验,但无法使 requires 正常工作。

   (ns todomvc.core
      (:require [reagent.core :as r]))

    (defonce todos (r/atom (sorted-map)))

    (defonce counter (r/atom 0))

    (defn add-todo [text]
      (let [id (swap! counter inc)]
        (swap! todos assoc id {:id id :title text :done false})))

    (defn toggle [id] (swap! todos update-in [id :done] not))
    (defn save [id title] (swap! todos assoc-in [id :title] title))
    (defn delete [id] (swap! todos dissoc id))

    (defn mmap [m f a] (->> m (f a) (into (empty m))))
    (defn complete-all [v] (swap! todos mmap map #(assoc-in % [1 :done] v)))
    (defn clear-done [] (swap! todos mmap remove #(get-in % [1 :done])))

现有地图作为函数的第一个参数传递。当所有其他方法都失败时...