simplify a little bit, rename Pis_none to Pis_not_none

Author: bobzhang

jscomp/core/js_exp_make.ml

@@ -531,6 +531,9 @@ let rec triple_equal ?comment (e0 : t) (e1 : t ) : t =
   | Undefined, Null -> caml_false
   | Null, Null
   | Undefined, Undefined -> caml_true
+  (* FIXME - this will change after we change the representation*)
+  | (Number _ | Undefined), Optional_block _  
+  | Optional_block _, (Number _ | Undefined)-> caml_false
   | _ -> 
      {expression_desc = Bin(EqEqEq, e0,e1); comment}
 

jscomp/core/js_of_lam_option.ml

@@ -108,8 +108,9 @@ let destruct_optional
 let none : J.expression = 
   {expression_desc = Number (Int {i = 0l; c  = None}); comment = Some "None" }
 
-(* let is_not_none  (e : J.expression) : J.expression =  *)
-
+let is_not_none  (e : J.expression) : J.expression = 
+  E.not (E.triple_equal e none)
+  
 
 let some  = E.optional_block