check for :lite-mode? - emit Vector if set

Author: swannodette

src/main/cljs/cljs/core.cljs

@@ -12232,9 +12232,9 @@ reduces them without incurring seq initialization"
 
 ;;; Vector
 
-(deftype Vector [meta array]
+(deftype Vector [meta array ^:mutable __hash]
   IWithMeta
-  (-with-meta [coll meta] (Vector. meta array))
+  (-with-meta [coll meta] (Vector. meta array __hash))
 
   IMeta
   (-meta [coll] meta)
@@ -12248,14 +12248,14 @@ reduces them without incurring seq initialization"
     (if (> (.-length array) 0)
       (let [new-array (aclone array)]
         (. new-array (pop))
-        (Vector. meta new-array))
+        (Vector. meta new-array nil))
       (throw (js/Error. "Can't pop empty vector"))))
 
   ICollection
   (-conj [coll o]
     (let [new-array (aclone array)]
       (.push new-array o)
-      (Vector. meta new-array)))
+      (Vector. meta new-array nil)))
 
   IEmptyableCollection
   (-empty [coll] (with-meta (. Vector -EMPTY) meta))
@@ -12298,7 +12298,7 @@ reduces them without incurring seq initialization"
   (-assoc [coll k v]
     (let [new-array (aclone array)]
       (aset new-array k v)
-      (Vector. meta new-array)))
+      (Vector. meta new-array nil)))
 
   IVector
   (-assoc-n [coll n val] (-assoc coll n val))
@@ -12318,9 +12318,9 @@ reduces them without incurring seq initialization"
   IPrintWithWriter
   (-pr-writer [coll writer opts] (pr-sequential-writer writer pr-writer "[" " " "]" opts coll)))
 
-(set! (. Vector -EMPTY) (Vector. nil (array)))
+(set! (. Vector -EMPTY) (Vector. nil (array) nil))
 
-(set! (. Vector -fromArray) (fn [xs] (Vector. nil xs)))
+(set! (. Vector -fromArray) (fn [xs] (Vector. nil xs nil)))
 
 ; The keys field is an array of all keys of this map, in no particular
 ; order. Any string, keyword, or symbol key is used as a property name

src/main/clojure/cljs/closure.clj

@@ -211,7 +211,7 @@
     :watch :watch-error-fn :watch-fn :install-deps :process-shim :rename-prefix :rename-prefix-namespace
     :closure-variable-map-in :closure-property-map-in :closure-variable-map-out :closure-property-map-out
     :stable-names :ignore-js-module-exts :opts-cache :aot-cache :elide-strict :fingerprint :spec-skip-macros
-    :nodejs-rt :target-fn :deps-cmd :bundle-cmd :global-goog-object&array :node-modules-dirs})
+    :nodejs-rt :target-fn :deps-cmd :bundle-cmd :global-goog-object&array :node-modules-dirs :lite-mode?})
 
 (def string->charset
   {"iso-8859-1" StandardCharsets/ISO_8859_1

src/main/clojure/cljs/compiler.cljc

@@ -522,6 +522,9 @@
     (and (every? #(= (:op %) :const) keys)
          (= (count (into #{} keys)) (count keys)))))
 
+(defn lite-mode? []
+  (get-in @env/*compiler* [:options :lite-mode?]))
+
 (defn emit-map [keys vals comma-sep distinct-keys?]
   (cond
     (zero? (count keys))
@@ -562,10 +565,17 @@
           ", 5, cljs.core.PersistentVector.EMPTY_NODE, ["  (comma-sep items) "], null)")
         (emits "cljs.core.PersistentVector.fromArray([" (comma-sep items) "], true)")))))
 
+(defn emit-lite-vector [items comma-sep]
+  (if (empty? items)
+    (emits "cljs.core.Vector.EMPTY")
+    (emits "new cljs.core.Vector(null, [" (comma-sep items) "], null)")))
+
 (defmethod emit* :vector
   [{:keys [items env]}]
   (emit-wrap env
-    (emit-vector items comma-sep)))
+    (if (lite-mode?)
+      (emit-lite-vector items comma-sep)
+      (emit-vector items comma-sep))))
 
 (defn distinct-constants? [items]
   (let [items (map ana/unwrap-quote items)]