#244 - Implicit navigator for maps

Adding implicit navigator for PersistentArrayMap that builds up a navigator recursively, using if-path to descend, and keypath and pred= for each of the map entries, with STAY as the base navigator (i.e. if all other have succeeded).

Adding tests

src/clj/com/rpl/specter.cljc

@@ -1468,3 +1468,24 @@
    [& path]
    (map compact* path)
    ))
+
+(defn- map-filter-helper [item-map keys]
+  (if (empty? keys)
+    STAY ; base case
+    (let [key (first keys) value (get item-map key)]
+      (if-path (i/combine-two-navs (n/keypath* key) (pred= value))
+               (map-filter-helper item-map (rest keys)))
+      )
+    ))
+
+(extend-type #?(:clj clojure.lang.PersistentArrayMap :cljs cljs.core/PersistentArrayMap)
+  ImplicitNav
+  (implicit-nav [this]
+    (map-filter-helper this (keys this))
+    ))
+
+(extend-type #?(:clj clojure.lang.PersistentHashMap :cljs cljs.core/PersistentHashMap)
+  ImplicitNav
+  (implicit-nav [this]
+    (map-filter-helper this (keys this))
+    ))

test/com/rpl/specter/core_test.cljc

@@ -1694,3 +1694,21 @@
       (is (satisfies-protpath? FooPP "a"))
       (is (not (satisfies-protpath? FooPP 1)))
       )))
+
+(deftest implicit-map-nav-test
+  (def my-x 100)
+  (let [ab-map {:a 1 :b 2}
+        c-map {:k 3 :l 4 :m 5}
+        abc-map (assoc ab-map :c c-map)]
+    (for [filter-map [ab-map abc-map {:c c-map} {}]]
+      ;; all of these cases should select the full map
+      (is (= [abc-map] (select [filter-map] abc-map)))
+    )
+    (is (= [] (select [{:a -9}] abc-map)))
+    (let [my-x 100]
+      (do
+        ;; test with binding
+        (is (= [] (select [{:x my-x :y 17}] {:x (+ my-x 1) :y 17})))
+        (is (= [{:x 100 :y 17}] (select [{:x my-x :y 17}] {:x 100 :y 17})))
+    ))
+  ))