Treat uncurried application of primitives like curried application

CHANGELOG.md

@@ -54,6 +54,7 @@ These are only breaking changes for unformatted code.
 - Remove method application via operator `##`, which does not exist in `.res` syntax https://github.com/rescript-lang/rescript-compiler/pull/5844
 - Treat `@meth` annotation as making the type uncurried for backwards compatibitly with some examples https://github.com/rescript-lang/rescript-compiler/pull/5845
 - Process `@set` annotation for field update as generating an uncurried function https://github.com/rescript-lang/rescript-compiler/pull/5846
+- Treat uncurried application of primitives like curried application, which produces better output https://github.com/rescript-lang/rescript-compiler/pull/5851
 
 # 10.1.0-rc.6
 

jscomp/ml/typecore.ml

@@ -2041,7 +2041,11 @@ and type_expect_ ?in_function ?(recarg=Rejected) env sexp ty_expected =
           exp_attributes = sexp.pexp_attributes;
           exp_env = env } in
 
-      if fully_applied then
+      let is_primitive = match funct.exp_desc with
+        | Texp_ident (_, _, {val_kind = Val_prim _}) -> true
+        | _ -> false in
+
+      if fully_applied && not is_primitive then
         rue (apply_internal "opaqueFullApply" (mk_apply (apply_internal "opaque" funct) args))
       else
         rue (mk_apply funct args)

jscomp/test/UncurriedExternals.js

@@ -26,11 +26,9 @@ function tg(arr) {
 
 var tc = Object.assign({}, "abc");
 
-var te = (function (prim) {
-      return prim;
-    })({
-      RE_EXN_ID: "Not_found"
-    });
+var te = {
+  RE_EXN_ID: "Not_found"
+};
 
 var tcr = {};
 
@@ -87,11 +85,9 @@ function tg$1(arr) {
 
 var tc$1 = Object.assign({}, "abc");
 
-var te$1 = (function (prim) {
-      return prim;
-    })({
-      RE_EXN_ID: "Not_found"
-    });
+var te$1 = {
+  RE_EXN_ID: "Not_found"
+};
 
 var tcr$1 = {};
 

jscomp/test/bs_splice_partial.js

@@ -32,7 +32,7 @@ function test_cb(x) {
 }
 
 function f(x) {
-  v(x);
+  Curry._1(v, x);
 }
 
 function testUndefined(param) {

lib/4.06.1/unstable/js_compiler.ml

@@ -42771,7 +42771,11 @@ and type_expect_ ?in_function ?(recarg=Rejected) env sexp ty_expected =
           exp_attributes = sexp.pexp_attributes;
           exp_env = env } in
 
-      if fully_applied then
+      let is_primitive = match funct.exp_desc with
+        | Texp_ident (_, _, {val_kind = Val_prim _}) -> true
+        | _ -> false in
+
+      if fully_applied && not is_primitive then
         rue (apply_internal "opaqueFullApply" (mk_apply (apply_internal "opaque" funct) args))
       else
         rue (mk_apply funct args)

lib/4.06.1/unstable/js_playground_compiler.ml

@@ -42771,7 +42771,11 @@ and type_expect_ ?in_function ?(recarg=Rejected) env sexp ty_expected =
           exp_attributes = sexp.pexp_attributes;
           exp_env = env } in
 
-      if fully_applied then
+      let is_primitive = match funct.exp_desc with
+        | Texp_ident (_, _, {val_kind = Val_prim _}) -> true
+        | _ -> false in
+
+      if fully_applied && not is_primitive then
         rue (apply_internal "opaqueFullApply" (mk_apply (apply_internal "opaque" funct) args))
       else
         rue (mk_apply funct args)

lib/4.06.1/whole_compiler.ml

@@ -97765,7 +97765,11 @@ and type_expect_ ?in_function ?(recarg=Rejected) env sexp ty_expected =
           exp_attributes = sexp.pexp_attributes;
           exp_env = env } in
 
-      if fully_applied then
+      let is_primitive = match funct.exp_desc with
+        | Texp_ident (_, _, {val_kind = Val_prim _}) -> true
+        | _ -> false in
+
+      if fully_applied && not is_primitive then
         rue (apply_internal "opaqueFullApply" (mk_apply (apply_internal "opaque" funct) args))
       else
         rue (mk_apply funct args)