use reduce-kv to optimize ALL transform on maps, significant performance boost

CHANGES.md

@@ -1,5 +1,6 @@
 ## 0.11.1 (unreleased)
 * More efficient inline caching for Clojure version, now inline caching is always within 5% of manually precompiled code
+* Significant performance improvement for ALL transform on maps for Clojure version (25% on simple benchmarks)
 
 ## 0.11.0
 * New `path` macro does intelligent inline caching of the provided path. The path is factored into a static portion and into params which may change on each usage of the path (e.g. local parameters). The static part is factored and compiled on the first run-through, and then re-used for all subsequent invocations. As an example, `[ALL (keypath k)]` is factored into `[ALL keypath]`, which is compiled and cached, and `[k]`, which is provided on each execution. If it is not possible to precompile the path (e.g. [ALL some-local-variable]), nothing is cached and the path will be compiled on each run-through.

src/clj/com/rpl/specter/impl.cljx

@@ -553,7 +553,15 @@
           (doall (map next-fn structure))
 
           (map? structure)
-          (->> structure (r/map vec) (r/map next-fn) (into empty-structure))
+          ;; reduce-kv is much faster than doing r/map through call to (into ...)
+          (reduce-kv
+            (fn [m k v]
+              (let [[newk newv] (next-fn [k v])]
+                (assoc m newk newv)
+                ))
+            empty-structure
+            structure
+            )
 
           :else
           (->> structure (r/map next-fn) (into empty-structure))