From 82f591a5d36b6dd67661ea60ec20a18bc93260ae Mon Sep 17 00:00:00 2001
From: Nathan Marz <nathan@nathanmarz.com>
Date: Wed, 20 Apr 2016 22:09:02 -0400
Subject: [PATCH] redefine filterer in terms of subselect

---
 src/clj/com/rpl/specter.cljx      | 34 ++++++++++---------------------
 src/clj/com/rpl/specter/impl.cljx | 13 ------------
 2 files changed, 11 insertions(+), 36 deletions(-)

diff --git a/src/clj/com/rpl/specter.cljx b/src/clj/com/rpl/specter.cljx
index 0889a3c..423b303 100644
--- a/src/clj/com/rpl/specter.cljx
+++ b/src/clj/com/rpl/specter.cljx
@@ -248,29 +248,6 @@
   (transform* [this structure next-fn]
     (i/codewalk-until afn next-fn structure)))
 
-(defn filterer
-  "Navigates to a view of the current sequence that only contains elements that
-  match the given selector path. An element matches the selector path if calling select
-  on that element with the selector path yields anything other than an empty sequence.
-
-   The input path may be parameterized, in which case the result of filterer
-   will be parameterized in the order of which the parameterized selectors
-   were declared."
-  [& path]
-  (fixed-pathed-path [late path]
-    (select* [this structure next-fn]
-      (->> structure (filter #(i/selected?* late %)) doall next-fn))
-    (transform* [this structure next-fn]
-      (let [[filtered ancestry] (i/filter+ancestry late structure)
-            ;; the vec is necessary so that we can get by index later
-            ;; (can't get by index for cons'd lists)
-            next (vec (next-fn filtered))]
-        (reduce (fn [curr [newi oldi]]
-                  (assoc curr oldi (get next newi)))
-                (vec structure)
-                ancestry))
-      )))
-
 (defn subselect
   "Navigates to a sequence that contains the results of (select ...),
   but is a view to the original structure that can be transformed.
@@ -347,6 +324,17 @@
         structure
         next-fn))))
 
+(defn filterer
+  "Navigates to a view of the current sequence that only contains elements that
+  match the given selector path. An element matches the selector path if calling select
+  on that element with the selector path yields anything other than an empty sequence.
+
+   The input path may be parameterized, in which case the result of filterer
+   will be parameterized in the order of which the parameterized selectors
+   were declared."
+  [& path]
+  (subselect ALL (selected? path)))
+
 (defn transformed
   "Navigates to a view of the current value by transforming it with the
    specified selector and update-fn.
diff --git a/src/clj/com/rpl/specter/impl.cljx b/src/clj/com/rpl/specter/impl.cljx
index bdd4acd..bd44a4e 100644
--- a/src/clj/com/rpl/specter/impl.cljx
+++ b/src/clj/com/rpl/specter/impl.cljx
@@ -482,19 +482,6 @@
     (get-cell ret)
     ))
 
-(defn filter+ancestry [path aseq]
-  (let [aseq (vec aseq)]
-    (reduce (fn [[s m :as orig] i]
-              (let [e (get aseq i)
-                    pos (count s)]
-                (if (selected?* path e)
-                  [(conj s e) (assoc m pos i)]
-                  orig
-                  )))
-            [[] {}]
-            (range (count aseq))
-            )))
-
 (defn key-select [akey structure next-fn]
   (next-fn (get structure akey)))