Merge pull request #3780 from BuckleScript/tweak_beltId

Tweak codegen to merge if branches

Author: bobzhang

jscomp/core/js_stmt_make.ml

@@ -213,18 +213,16 @@ let rec if_ ?comment  ?declaration ?else_ (e : J.expression) (then_ : J.block)
   let common_prefix_blocks = ref [] in 
   let add_prefix b = common_prefix_blocks := b :: !common_prefix_blocks in 
   let rec aux ?comment (e : J.expression) (ifso : J.block) (ifnot : J.block ): t  =
-    match e.expression_desc with 
-    | Bool boolean -> 
+    match e.expression_desc,ifnot  with 
+    | Bool boolean, _ -> 
       block (if boolean then ifso else ifnot) 
-    | Js_not pred_not
+    | Js_not pred_not, (_::_)
       -> aux ?comment pred_not ifnot ifso
     | _ -> 
       match ifso, ifnot with 
       |  [], [] -> exp e 
       |  [], _ ->
-        {
-          statement_desc = If ( E.not e, ifnot, []); comment
-        }
+         aux ?comment (E.not e) ifnot [] (*Make sure no infinite loop*)        
       | [ {statement_desc = Return {return_value = ret_ifso; _}; _}], 
         [ {statement_desc = Return {return_value = ret_ifnot; _}; _} as _ifnot_stmt]
         ->      

jscomp/others/belt_Id.ml

@@ -49,8 +49,7 @@ module MakeComparableU (M : sig
   end) =
 struct
   type identity
-  type t = M.t
-  let cmp = M.cmp
+  include M
 end
 
 module MakeComparable (M : sig
@@ -69,11 +68,11 @@ let comparableU
   (type key)
   ~cmp
   =
-  let module N = MakeComparableU(struct
+  (module MakeComparableU(struct
       type t = key
       let cmp = cmp
-    end) in
-  (module N : Comparable with type t = key)
+    end) 
+  : Comparable with type t = key)
 
 let comparable
   (type key)
@@ -101,9 +100,7 @@ module MakeHashableU (M : sig
   end) =
 struct
   type identity
-  type t = M.t
-  let hash = M.hash
-  let eq = M.eq
+  include M
 end
 
 module MakeHashable (M : sig
@@ -121,12 +118,11 @@ struct
 end
 
 let hashableU (type key) ~hash ~eq =
-  let module N = MakeHashableU(struct
-    type t = key
-    let hash = hash
-    let eq = eq
-  end) in
-  (module N : Hashable with type t = key)
+  (module MakeHashableU(struct
+       type t = key
+       let hash = hash
+       let eq = eq
+     end) : Hashable with type t = key)
 
 let hashable (type key) ~hash ~eq =
   let module N = MakeHashable(struct