From e571df58328f631aee5b3310088c2d6fe27690e6 Mon Sep 17 00:00:00 2001
From: Nathan Marz <nathan@nathanmarz.com>
Date: Thu, 1 Sep 2016 16:59:40 -0400
Subject: [PATCH] add code to avoid embedding functions with metadata on them
 (which kills perf)

---
 src/clj/com/rpl/specter/impl.cljc  | 19 +++++++++++++++----
 src/clj/com/rpl/specter/macros.clj |  5 ++---
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/src/clj/com/rpl/specter/impl.cljc b/src/clj/com/rpl/specter/impl.cljc
index 6ca49e5..61e5b69 100644
--- a/src/clj/com/rpl/specter/impl.cljc
+++ b/src/clj/com/rpl/specter/impl.cljc
@@ -603,14 +603,24 @@
 (defn dynamic-var? [v]
   (-> v meta :dynamic))
 
+(defn direct-nav-obj [o]
+  (vary-meta o merge {:direct-nav true :original-obj o}))
+
 (defn maybe-direct-nav [obj direct-nav?]
   (if direct-nav?
-    (vary-meta obj assoc :direct-nav true)
+    (direct-nav-obj obj)
     obj))
 
+(defn original-obj [o]
+  (let [orig (-> o meta :original-obj)]
+    (if orig
+      (recur orig)
+      o)))
+
 (defn direct-nav? [o]
   (-> o meta :direct-nav))
 
+
 ;; don't do coerce-nav here... save that for resolve-magic-code
 (defn- magic-precompilation* [o]
   (cond (sequential? o)
@@ -680,13 +690,13 @@
   (cond (instance? DynamicFunction o)
         (let [op (resolve-dynamic-fn-arg-code (:op o))
               params (map resolve-dynamic-fn-arg-code (:params o))]
-          `(~op ~@params))
+          `(~(original-obj op) ~@params))
 
         (instance? DynamicVal o)
         (:code o)
 
         :else
-        o))
+        (original-obj o)))
 
 
 (defn resolve-magic-code [o]
@@ -716,7 +726,8 @@
           params (map resolve-dynamic-fn-arg (:params o))]
       (if (all-static? (conj params op))
         (coerce-nav (apply op params))
-        (let [code `(~(resolve-dynamic-fn-arg-code op) ~@(map resolve-dynamic-fn-arg-code params))]
+        (let [code `(~(-> op resolve-dynamic-fn-arg-code original-obj)
+                      ~@(map resolve-dynamic-fn-arg-code params))]
           (if (direct-nav? op) code `(coerce-nav ~code)))))
 
     :else
diff --git a/src/clj/com/rpl/specter/macros.clj b/src/clj/com/rpl/specter/macros.clj
index 10ebc10..2b8b3bd 100644
--- a/src/clj/com/rpl/specter/macros.clj
+++ b/src/clj/com/rpl/specter/macros.clj
@@ -14,11 +14,10 @@
 (defmacro richnav [params & impls]
   (if (empty? params)
     `(reify RichNavigator ~@impls)
-    `(vary-meta
+    `(i/direct-nav-obj
        (fn ~params
          (reify RichNavigator
-           ~@impls))
-       assoc :direct-nav true)))
+           ~@impls)))))
 
 
 (defmacro nav [params & impls]