How to add a child to a tree using clojure.zip?

问题

Consider the following code

(def v (z/vector-zip [1 [2 [3 4]]]))

where z refers to clojure.zip.

Now, how do I create from v the vector

[1 [2 [3 [4 5]]]]

using functions from the API for clojure.zip ? So starting with

(-> 
 v 
 ...

回答1:

Just use function edit

(defn edit
  "Replaces the node at this loc with the value of (f node args)"
  [loc f & args]
    (replace loc (apply f (node loc) args)))

Example

(-> v
    (z/down)
    (z/right)
    (z/down)
    (z/right)
    (z/down)
    (z/right)
    (z/edit #(do [% 5]))
    (z/root))

And the result will be

=> [1 [2 [3 [4 5]]]]

来源：https://stackoverflow.com/questions/37484870/how-to-add-a-child-to-a-tree-using-clojure-zip