Pass keys to tag readers via opts.

src/aero/core.cljc

@@ -217,13 +217,23 @@
   (fn [v]
     (tagged-literal (:tag tl) v)))
 
+(defn- pop*
+  [ks]
+  ;; pop doesn't work with clojure.lang.Cons so we use pop
+  ;; for vector and rest for anything that resembles a list
+  (if (vector? ks)
+    (pop ks)
+    (rest ks)))
+
 (defmethod eval-tagged-literal :default
   [tl opts env ks]
   (let [{:keys [:aero.core/incomplete?] :as expansion}
         (expand (:form tl) opts env ks)]
     (if incomplete?
       (update expansion ::value (rewrap tl))
-      (update expansion ::value #(reader opts (:tag tl) %)))))
+      (update expansion ::value #(reader (assoc opts :key-path (pop* ks))
+                                         (:tag tl)
+                                         %)))))
 
 (defmethod eval-tagged-literal 'ref
   [tl opts env ks]

test/aero/core_test.cljc

@@ -36,6 +36,10 @@
   [opts tag value]
   (if (= value :favorite) :chocolate :vanilla))
 
+(defmethod reader 'return-key-path
+  [opts _ _]
+  (:key-path opts))
+
 (deftest basic-test
   (let [config (read-config "test/aero/config.edn")]
     (is (= "Hello World!" (:greeting config))))
@@ -250,3 +254,10 @@
     {:a :b}
     #{:a :b}
     '(1)))
+
+(deftest pass-keys-to-reader
+  (is (= [:a :b :c]
+         (get-in (read-config
+                  (string-reader
+                   "{:a {:b {:c #return-key-path 1}}}"))
+          [:a :b :c]))))