Merge worktree-typed into macros: defcomp type annotations

shared/sx/ref/js.sx

@@ -1369,9 +1369,16 @@
         ;; Inline lambda → for loop
         (let ((params (nth fn-expr 1))
               (body (rest (rest fn-expr)))
-              (p (if (= (type-of (first params)) "symbol")
-                   (symbol-name (first params))
-                   (str (first params))))
+              (raw-p (first params))
+              (p (cond
+                   (= (type-of raw-p) "symbol")
+                     (symbol-name raw-p)
+                   ;; (name :as type) annotation → extract name
+                   (and (= (type-of raw-p) "list") (= (len raw-p) 3)
+                        (= (type-of (nth raw-p 1)) "keyword")
+                        (= (keyword-name (nth raw-p 1)) "as"))
+                     (symbol-name (first raw-p))
+                   :else (str raw-p)))
               (p-js (js-mangle p)))
           (str "{ var _c = " coll "; for (var _i = 0; _i < _c.length; _i++) { var "
                p-js " = _c[_i]; "