It's simple. Just like that:

```
> clojure.walk/walk:
(outer (reduce (fn [r x] (conj r (inner x))) form form))
=> (outer (into form (map inner) form))
(outer (into (empty form) (map inner form)))
=> (outer (into (empty form) (map inner) form))
```

```
> clojure.walk/keywordize-keys:
(postwalk (fn [x] (if (map? x) (into {} (map f x)) x)) m)
=> (postwalk (fn [x] (if (map? x) (into {} (map f) x) x)) m)
```

```
> clojure.walk/strigify-keys:
(postwalk (fn [x] (if (map? x) (into {} (map f x)) x)) m)
=> (postwalk (fn [x] (if (map? x) (into {} (map f) x) x)) m)
```