From ff03dbc834dc06cab108eb82b6d48c2b7c4004c5 Mon Sep 17 00:00:00 2001
From: Nathan Marz <nathan@nathanmarz.com>
Date: Thu, 9 Jun 2016 16:36:20 -0400
Subject: [PATCH 1/3] implement traverse

---
 scripts/benchmarks.clj             | 10 ++++++++++
 src/clj/com/rpl/specter.cljx       | 11 +++++++++++
 src/clj/com/rpl/specter/impl.cljx  | 14 ++++++++++++++
 src/clj/com/rpl/specter/macros.clj |  9 +++++++++
 4 files changed, 44 insertions(+)

diff --git a/scripts/benchmarks.clj b/scripts/benchmarks.clj
index cf80a41..7dc0450 100644
--- a/scripts/benchmarks.clj
+++ b/scripts/benchmarks.clj
@@ -52,6 +52,15 @@
        (println "\n********************************\n")
        )))
 
+(let [data (range 1000)]
+  (run-benchmark "Traverse into a set" 5000
+    (set data)
+    (set (select ALL data))
+    (persistent!
+      (reduce conj! (transient #{}) (traverse ALL data)))
+    (reduce conj #{} (traverse ALL data))
+    ))
+
 (let [data {:a {:b {:c 1}}}
       p (comp-paths :a :b :c)]
   (run-benchmark "get value in nested map" 5000000
@@ -243,3 +252,4 @@
     2000000
     (vary-meta data assoc :y 2)
     (setval [META :y] 2 data)))
+
diff --git a/src/clj/com/rpl/specter.cljx b/src/clj/com/rpl/specter.cljx
index 9d185ac..f7b60da 100644
--- a/src/clj/com/rpl/specter.cljx
+++ b/src/clj/com/rpl/specter.cljx
@@ -104,6 +104,17 @@
   [path structure]
   (compiled-selected-any? (i/comp-paths* path) structure))
 
+;; Reducible traverse functions
+
+(def ^{:doc "Version of traverse that takes in a path pre-compiled with comp-paths"}
+  compiled-traverse i/do-compiled-traverse)
+
+(defn traverse*
+  "Return a reducible object that traverses over `structure` to every element
+   specified by the path"
+  [apath structure]
+  (compiled-traverse (i/comp-paths* apath) structure))
+
 ;; Transformation functions
 
 (def ^{:doc "Version of transform that takes in a path pre-compiled with comp-paths"}
diff --git a/src/clj/com/rpl/specter/impl.cljx b/src/clj/com/rpl/specter/impl.cljx
index 56aa909..00e6da7 100644
--- a/src/clj/com/rpl/specter/impl.cljx
+++ b/src/clj/com/rpl/specter/impl.cljx
@@ -652,6 +652,20 @@
       structure)
     ))
 
+(defn do-compiled-traverse [apath structure]
+  (reify clojure.lang.IReduceInit
+    (reduce [this afn start]
+      (let [cell (mutable-cell start)]
+        (compiled-traverse*
+          apath
+          (fn [elem]
+            (let [curr (get-cell cell)]
+              (set-cell! cell (afn curr elem))
+              ))
+          structure
+          )
+        (get-cell cell)
+        ))))
 
 (defn compiled-select* [path structure]
   (let [res (mutable-cell (transient []))
diff --git a/src/clj/com/rpl/specter/macros.clj b/src/clj/com/rpl/specter/macros.clj
index 1f2caaa..a0014e3 100644
--- a/src/clj/com/rpl/specter/macros.clj
+++ b/src/clj/com/rpl/specter/macros.clj
@@ -599,6 +599,15 @@
   [apath aval structure]
   `(i/compiled-setval* (path ~apath) ~aval ~structure))
 
+(defmacro traverse
+  "Return a reducible object that traverses over `structure` to every element
+   specified by the path.
+   This macro will attempt to do inline factoring and caching of the path, falling
+   back to compiling the path on every invocation it it's not possible to 
+   factor/cache the path."
+  [apath structure]
+  `(i/do-compiled-traverse (path ~apath) ~structure))
+
 (defmacro replace-in
   "Similar to transform, except returns a pair of [transformed-structure sequence-of-user-ret].
    The transform-fn in this case is expected to return [ret user-ret]. ret is

From 02a4bf09ca8889b7127e6d7d8c384763b98dc3a5 Mon Sep 17 00:00:00 2001
From: Nathan Marz <nathan@nathanmarz.com>
Date: Thu, 9 Jun 2016 16:43:03 -0400
Subject: [PATCH 2/3] upgrade to clojure 1.7.0 for reducers

---
 project.clj            | 2 +-
 scripts/benchmarks.clj | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/project.clj b/project.clj
index 927e9a3..d21da7a 100644
--- a/project.clj
+++ b/project.clj
@@ -41,7 +41,7 @@
                                     :output-path "target/test-classes"
                                     :rules :cljs}]}
                    }
-             :test {:dependencies [[org.clojure/clojure "1.6.0"]]}
+             :test {:dependencies [[org.clojure/clojure "1.7.0"]]}
              }
   :aliases {"cleantest" ["do" "clean,"
                          "cljx" "once,"
diff --git a/scripts/benchmarks.clj b/scripts/benchmarks.clj
index 7dc0450..d7844b9 100644
--- a/scripts/benchmarks.clj
+++ b/scripts/benchmarks.clj
@@ -56,6 +56,7 @@
   (run-benchmark "Traverse into a set" 5000
     (set data)
     (set (select ALL data))
+    (into #{} (traverse ALL data))
     (persistent!
       (reduce conj! (transient #{}) (traverse ALL data)))
     (reduce conj #{} (traverse ALL data))

From e7aae0cb0fc8e025b9745725c570a011fa53c2d5 Mon Sep 17 00:00:00 2001
From: Nathan Marz <nathan@nathanmarz.com>
Date: Thu, 9 Jun 2016 17:21:11 -0400
Subject: [PATCH 3/3] add non-init reduce case to traverse

---
 src/clj/com/rpl/specter/impl.cljx | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/clj/com/rpl/specter/impl.cljx b/src/clj/com/rpl/specter/impl.cljx
index 00e6da7..3d48d0b 100644
--- a/src/clj/com/rpl/specter/impl.cljx
+++ b/src/clj/com/rpl/specter/impl.cljx
@@ -653,7 +653,9 @@
     ))
 
 (defn do-compiled-traverse [apath structure]
-  (reify clojure.lang.IReduceInit
+  (reify clojure.lang.IReduce
+    (reduce [this afn]
+      (.reduce this afn (afn)))
     (reduce [this afn start]
       (let [cell (mutable-cell start)]
         (compiled-traverse*