DEV: Add Matcher to hide clj/cljs implementation details

cljfmt/src/cljfmt/core.cljc

@@ -408,33 +408,30 @@
        (some-> zloc z/up ns-form?)
        (-> zloc z/sexpr first ns-reference-symbols)))
 
-#?(:cljs
-   (defn- re-seq-matcher [re charmap coll]
-     {:pre (every? charmap coll)}
-     (let [s (apply str (map charmap coll))
-           v (vec coll)
-           m (js/RegExp. re.source "g")]
-       (letfn [(next-match []
-                 (when-let [result (.exec m s)]
-                   (let [start result.index
-                         end m.lastIndex]
-                     {:value (subvec v start end)
-                      :start start
-                      :end end})))]
-         (take-while some? (repeatedly next-match)))))
-
-   :clj
-   (defn- re-seq-matcher [re charmap coll]
-     {:pre (every? charmap coll)}
-     (let [s (apply str (map charmap coll))
-           v (vec coll)
-           m (re-matcher re s)]
-       (letfn [(next-match []
-                 (when (.find m)
-                   {:value (subvec v (.start m) (.end m))
-                    :start (.start m)
-                    :end   (.end m)}))]
-         (take-while some? (repeatedly next-match))))))
+(defprotocol Matcher
+  (find-next [this]))
+
+(defn- matcher [re s]
+  (let [m #?(:clj (re-matcher re s)
+             :cljs (js/RegExp. re.source "g"))]
+    (reify Matcher
+      (find-next [_this]
+        #?(:clj (when (.find m)
+                   {:start (.start m)
+                    :end   (.end m)})
+           :cljs (when-let [result (.exec m s)]
+                   {:start result.index
+                    :end   m.lastIndex}))))))
+
+(defn- re-seq-matcher [re charmap coll]
+  {:pre (every? charmap coll)}
+  (let [s (apply str (map charmap coll))
+        v (vec coll)
+        m (matcher re s)]
+    (letfn [(next-match []
+              (when-let [{:keys [start end] :as match} (find-next m)]
+                (assoc match :value (subvec v start end))))]
+    (take-while some? (repeatedly next-match)))))
 
 (defn- find-elements-with-comments [nodes]
   (re-seq-matcher #"(CNS*)*E(S*C)?"