reduce an indirection for unwrap

Author: bobzhang

jscomp/core/js_of_lam_option.ml

@@ -93,7 +93,7 @@ let get_default_undefined_from_optional
     else
       (E.runtime_call Js_runtime_modules.option "option_get" [arg])
 
-let get_default_undefined (arg : J.expression) : J.expression =
+let option_unwrap (arg : J.expression) : J.expression =
   let desc = arg.expression_desc in
   if is_none_static desc then E.undefined else
   match desc with
@@ -102,12 +102,7 @@ let get_default_undefined (arg : J.expression) : J.expression =
     Js_of_lam_polyvar.get_field x 
     (* invariant: option encoding *)
   | _ ->
-    (* FIXME: no need do such inlining*)
-    if Js_analyzer.is_okay_to_duplicate arg then
-      E.econd (is_not_none arg) 
-        (Js_of_lam_polyvar.get_field (val_from_option arg)) E.undefined
-    else
-      E.runtime_call Js_runtime_modules.option "option_get_unwrap" [arg]
+    E.runtime_call Js_runtime_modules.option "option_unwrap" [arg]
 
 let destruct_optional
   ~for_sure_none

jscomp/core/js_of_lam_option.mli

@@ -44,7 +44,7 @@ val get_default_undefined_from_optional:
 
 (** Given [Some (`a x)] or [None], 
     return [x] *)  
-val get_default_undefined : 
+val option_unwrap : 
   J.expression ->
   J.expression
 

jscomp/core/lam_compile_external_call.ml

@@ -139,8 +139,10 @@ let ocaml_to_js_eff
            - if ocaml arg is `None`, let js arg be `undefined` (no unwrapping)
            - if ocaml arg is `Some x`, unwrap the arg to get the `x`, then
              unwrap the `x` itself
+           - Here `Some x` is `x` due to the current encoding
+           Lets inline here since it depends on the runtime encoding
         *)
-        Js_of_lam_option.get_default_undefined raw_arg
+        Js_of_lam_option.option_unwrap raw_arg
       | _ ->
         Js_of_lam_variant.eval_as_unwrap raw_arg
     in

jscomp/runtime/caml_option.ml

@@ -74,7 +74,7 @@ let option_get (x : 'a option) =
 
 
 (** [input] is optional polymorphic variant *)  
-let option_get_unwrap (x : 'a option)  =
+let option_unwrap (x : 'a option)  =
   if x = None then Caml_undefined_extern.empty
-  else Obj.magic (Obj.field (Obj.repr (valFromOption (Obj.repr x))) 1 )
-
+  else Obj.magic (Obj.field (Obj.repr ((Obj.repr x))) 1 )
+(* INVARIANT: polyvar encoding*)

jscomp/runtime/caml_option.mli

@@ -35,4 +35,7 @@ val some : Obj.t -> Obj.t
 
 val option_get : Obj.t option -> Obj.t Caml_undefined_extern.t 
 
-val option_get_unwrap : 'a option -> Obj.t Caml_undefined_extern.t
+(** When it is None, return none
+    When it is (Some (`a 3)) return 3
+*)
+val option_unwrap : 'a option -> Obj.t Caml_undefined_extern.t

jscomp/syntax/ast_external_process.ml

@@ -67,7 +67,8 @@ let spec_of_ptyp
     begin match ptyp_desc with
       | Ptyp_variant (row_fields, Closed, _)
         when variant_unwrap row_fields ->
-        Unwrap
+        Unwrap 
+        (* Unwrap attribute can only be attached to things like `[a of a0 | b of b0]` *)
       | _ ->
         Bs_syntaxerr.err ptyp.ptyp_loc Invalid_bs_unwrap_type
     end

jscomp/test/bs_unwrap_test.js

@@ -44,14 +44,14 @@ var some_arg = /* `Bool */[
   true
 ];
 
-console.log(5, some_arg !== undefined ? Caml_option.valFromOption(some_arg)[1] : undefined);
+console.log(5, Caml_option.option_unwrap(some_arg));
 
 console.log(6, undefined);
 
-console.log(7, Caml_option.option_get_unwrap((console.log("trace"), undefined)));
+console.log(7, Caml_option.option_unwrap((console.log("trace"), undefined)));
 
 function dyn_log3(prim, prim$1, prim$2) {
-  console.log(prim[1], prim$1 !== undefined ? Caml_option.valFromOption(prim$1)[1] : undefined);
+  console.log(prim[1], Caml_option.option_unwrap(prim$1));
 
 }
 
@@ -84,12 +84,12 @@ function f(x) {
 }
 
 function ff0(x, p) {
-  console.log(x !== undefined ? Caml_option.valFromOption(x)[1] : undefined, p);
+  console.log(Caml_option.option_unwrap(x), p);
 
 }
 
 function ff1(x, p) {
-  console.log(Caml_option.option_get_unwrap(Curry._1(x, undefined)), p);
+  console.log(Caml_option.option_unwrap(Curry._1(x, undefined)), p);
 
 }
 

lib/es6/caml_option.js

@@ -71,11 +71,11 @@ function option_get(x) {
   }
 }
 
-function option_get_unwrap(x) {
+function option_unwrap(x) {
   if (x === undefined) {
     return ;
   } else {
-    return valFromOption(x)[1];
+    return x[1];
   }
 }
 
@@ -86,7 +86,7 @@ export {
   valFromOption ,
   some ,
   option_get ,
-  option_get_unwrap ,
+  option_unwrap ,
 
 }
 /* No side effect */

lib/js/caml_option.js

@@ -71,11 +71,11 @@ function option_get(x) {
   }
 }
 
-function option_get_unwrap(x) {
+function option_unwrap(x) {
   if (x === undefined) {
     return ;
   } else {
-    return valFromOption(x)[1];
+    return x[1];
   }
 }
 
@@ -85,5 +85,5 @@ exports.null_to_opt = null_to_opt;
 exports.valFromOption = valFromOption;
 exports.some = some;
 exports.option_get = option_get;
-exports.option_get_unwrap = option_get_unwrap;
+exports.option_unwrap = option_unwrap;
 /* No side effect */