detect array like records

Author: bobzhang

jscomp/core/js_dump.ml

@@ -816,7 +816,10 @@ and expression_desc cxt ~(level:int) f x : cxt  =
           fields el 
           (fun  x -> Js_op.Lit (Ext_ident.convert x) ))))
   (*name convention of Record is slight different from modules*)        
-  | Caml_block(el,_, _, Blk_record fields) ->        
+  | Caml_block(el,mutable_flag, _, Blk_record fields) ->  
+    if Ext_array.for_alli fields (fun i v -> string_of_int i = v) then 
+      expression_desc cxt ~level f  (Array (el, mutable_flag))
+    else      
       expression_desc cxt ~level f (Object 
         ((Ext_list.combine_array fields el  (fun i -> Js_op.Lit i))))      
 

jscomp/ext/ext_array.ml

@@ -234,6 +234,14 @@ let rec unsafe_loop index len p xs ys  =
       (Array.unsafe_get ys index) &&
     unsafe_loop (succ index) len p xs ys 
 
+let for_alli a p =
+  let n = Array.length a in
+  let rec loop i =
+    if i = n then true
+    else if p i (Array.unsafe_get a i) then loop (succ i)
+    else false in
+  loop 0
+
 let for_all2_no_exn xs ys p = 
   let len_xs = Array.length xs in 
   let len_ys = Array.length ys in 

jscomp/ext/ext_array.mli

@@ -87,6 +87,11 @@ val for_all2_no_exn :
   ('a -> 'b -> bool) -> 
   bool
 
+val for_alli : 
+  'a array -> 
+  (int -> 'a -> bool) -> 
+  bool 
+    
 val map :   
   'a array -> 
   ('a -> 'b) ->