From 6d028cbe2425f7c905c6fe4a88aa9e927161e902 Mon Sep 17 00:00:00 2001
From: Nathan Marz <nathan@nathanmarz.com>
Date: Mon, 22 Jun 2015 14:37:39 -0400
Subject: [PATCH] change filterer so it accepts a path that acts like selected?

---
 src/clj/com/rpl/specter.clj      |  2 +-
 src/clj/com/rpl/specter/impl.clj | 41 +++++++++++++++++++-------------
 2 files changed, 25 insertions(+), 18 deletions(-)

diff --git a/src/clj/com/rpl/specter.clj b/src/clj/com/rpl/specter.clj
index 71da0e7..d46c448 100644
--- a/src/clj/com/rpl/specter.clj
+++ b/src/clj/com/rpl/specter.clj
@@ -129,7 +129,7 @@
 
 (defn codewalker [afn] (->CodeWalkerStructurePath afn))
 
-(defn filterer [afn] (->FilterStructurePath afn))
+(defn filterer [& path] (->FilterStructurePath (comp-paths* path)))
 
 (defn keypath [akey] (->KeyPath akey))
 
diff --git a/src/clj/com/rpl/specter/impl.clj b/src/clj/com/rpl/specter/impl.clj
index 14e6d99..8113b79 100644
--- a/src/clj/com/rpl/specter/impl.clj
+++ b/src/clj/com/rpl/specter/impl.clj
@@ -301,6 +301,25 @@
 (defn- conj-all! [cell elems]
   (set-cell! cell (concat (get-cell cell) elems)))
 
+(defn compiled-select*
+  [^com.rpl.specter.impl.TransformFunctions tfns structure]
+  (let [^com.rpl.specter.impl.ExecutorFunctions ex (.executors tfns)]
+    ((.select-executor ex) (.selector tfns) structure)
+    ))
+
+(defn compiled-update*
+  [^com.rpl.specter.impl.TransformFunctions tfns update-fn structure]
+  (let [^com.rpl.specter.impl.ExecutorFunctions ex (.executors tfns)]
+    ((.update-executor ex) (.updater tfns) update-fn structure)
+    ))
+
+(defn selected?*
+  [compiled-path structure]
+  (->> structure
+       (compiled-select* compiled-path)
+       empty?
+       not))
+
 ;; returns vector of all results
 (defn- walk-select [pred continue-fn structure]
   (let [ret (mutable-cell [])
@@ -313,12 +332,12 @@
     (get-cell ret)
     ))
 
-(defn- filter+ancestry [afn aseq]
+(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 (afn e)
+                (if (selected?* path e)
                   [(conj s e) (assoc m pos i)]
                   orig
                   )))
@@ -391,14 +410,14 @@
     (codewalk-until (.afn this) next-fn structure)))
 
 
-(deftype FilterStructurePath [afn])
+(deftype FilterStructurePath [path])
 
 (extend-protocol StructurePath
   FilterStructurePath
   (select* [^FilterStructurePath this structure next-fn]
-    (->> structure (filter (.afn this)) doall next-fn))
+    (->> structure (filter #(selected?* (.path this) %)) doall next-fn))
   (update* [^FilterStructurePath this structure next-fn]
-    (let [[filtered ancestry] (filter+ancestry (.afn this) structure)
+    (let [[filtered ancestry] (filter+ancestry (.path this) 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))]
@@ -473,18 +492,6 @@
     (next-fn structure)
     ))
 
-(defn compiled-select*
-  [^com.rpl.specter.impl.TransformFunctions tfns structure]
-  (let [^com.rpl.specter.impl.ExecutorFunctions ex (.executors tfns)]
-    ((.select-executor ex) (.selector tfns) structure)
-    ))
-
-(defn compiled-update*
-  [^com.rpl.specter.impl.TransformFunctions tfns update-fn structure]
-  (let [^com.rpl.specter.impl.ExecutorFunctions ex (.executors tfns)]
-    ((.update-executor ex) (.updater tfns) update-fn structure)
-    ))
-
 (deftype ConditionalPath [cond-pairs])
 
 (defn- retrieve-selector [cond-pairs structure]