handle sets

Author: swannodette

src/main/cljs/cljs/core.cljs

@@ -12721,3 +12721,15 @@ reduces them without incurring seq initialization"
   (-pr-writer [coll writer opts] (pr-sequential-writer writer pr-writer "#{" " " "}" opts coll)))
 
 (set! (. Set -EMPTY) (Set. nil (. HashMap -EMPTY) empty-unordered-hash))
+
+(defn simple-set
+  [coll]
+  (if (set? coll)
+    (with-meta coll nil)
+    (let [in (seq coll)]
+      (if (nil? in)
+        #{}
+        (loop [in in out (. Set -EMPTY)]
+          (if-not (nil? in)
+            (recur (next in) (conj out (first in)))
+            out))))))

src/main/clojure/cljs/compiler.cljc

@@ -616,10 +616,17 @@
 
     :else (emits "cljs.core.PersistentHashSet.createAsIfByAssoc([" (comma-sep items) "])")))
 
+(defn emit-lite-set [items comma-sep distinct-constants?]
+  (if (empty? items)
+    (emits "cljs.core.Set.EMPTY")
+    (emits "cljs.core.simple_set([" (comma-sep items) "])")))
+
 (defmethod emit* :set
   [{:keys [items env]}]
   (emit-wrap env
-    (emit-set items comma-sep distinct-constants?)))
+    (if (ana/lite-mode?)
+      (emit-lite-set items comma-sep distinct-constants?)
+      (emit-set items comma-sep distinct-constants?))))
 
 (defn emit-js-object [items emit-js-object-val]
   (emits "({")