Dict as a builtin (#6590)

* dict as a builtin type

* fix

* revert unintended changes

* adapt gentype to dict as built in

* changelog

Author: zth

CHANGELOG.md

@@ -16,6 +16,7 @@
 
 - Experimental support of tagged template literals, eg ```sql`select * from ${table}```. https://github.com/rescript-lang/rescript-compiler/pull/6250
 - Experimental support for generic/custom JSX transforms. https://github.com/rescript-lang/rescript-compiler/pull/6565
+- `dict` is now a builtin type. https://github.com/rescript-lang/rescript-compiler/pull/6590
 
 #### :bug: Bug Fix
 

jscomp/gentype/TranslateTypeExprFromTypes.ml

@@ -236,7 +236,7 @@ let translateConstr ~config ~paramsTranslation ~(path : Path.t) ~typeEnv =
   | ( (["Js"; "Promise"; "t"] | ["Promise"; "t"] | ["promise"]),
       [paramTranslation] ) ->
     {paramTranslation with type_ = Promise paramTranslation.type_}
-  | (["Js"; "Dict"; "t"] | ["Dict"; "t"]), [paramTranslation] ->
+  | (["Js"; "Dict"; "t"] | ["Dict"; "t"] | ["dict"]), [paramTranslation] ->
     {paramTranslation with type_ = Dict paramTranslation.type_}
   | ["function$"], [arg; _arity] ->
     {dependencies = arg.dependencies; type_ = arg.type_}

jscomp/ml/ast_untagged_variants.ml

@@ -142,6 +142,7 @@ let reportConstructorMoreThanOneArg ~loc ~name =
 
 let type_is_builtin_object (t : Types.type_expr) =
   match t.desc with
+  | Tconstr (Path.Pident ident, [_], _) when Ident.name ident = "dict" -> true
   | Tconstr (path, _, _) ->
     let name = Path.name path in
     name = "Js.Dict.t" || name = "Js_dict.t"

jscomp/ml/predef.ml

@@ -40,6 +40,7 @@ and ident_array = ident_create "array"
 and ident_list = ident_create "list"
 and ident_option = ident_create "option"
 and ident_result = ident_create "result"
+and ident_dict = ident_create "dict"
 
 and ident_int64 = ident_create "int64"
 and ident_lazy_t = ident_create "lazy_t"
@@ -82,6 +83,7 @@ and path_array = Pident ident_array
 and path_list = Pident ident_list
 and path_option = Pident ident_option
 and path_result = Pident ident_result
+and path_dict = Pident ident_dict
 
 
 and path_int64 = Pident ident_int64
@@ -105,6 +107,7 @@ and type_array t = newgenty (Tconstr(path_array, [t], ref Mnil))
 and type_list t = newgenty (Tconstr(path_list, [t], ref Mnil))
 and type_option t = newgenty (Tconstr(path_option, [t], ref Mnil))
 and type_result t1 t2 = newgenty (Tconstr(path_result, [t1; t2], ref Mnil))
+and type_dict t = newgenty (Tconstr(path_dict, [t], ref Mnil))
 
 and type_int64 = newgenty (Tconstr(path_int64, [], ref Mnil))
 and type_lazy_t t = newgenty (Tconstr(path_lazy_t, [t], ref Mnil))
@@ -226,6 +229,12 @@ let common_initial_env add_type add_extension empty_env =
      Type_variant([cstr ident_ok [tvar1];
                    cstr ident_error [tvar2]]);
      type_variance = [Variance.covariant; Variance.covariant]}
+  and decl_dict =
+    let tvar = newgenvar() in
+    {decl_abstr with
+      type_params = [tvar];
+      type_arity = 1;
+      type_variance = [Variance.covariant]}
   and decl_uncurried =
     let tvar1, tvar2 = newgenvar(), newgenvar() in
     {decl_abstr with
@@ -292,6 +301,7 @@ let common_initial_env add_type add_extension empty_env =
   add_type ident_lazy_t decl_lazy_t (
   add_type ident_option decl_option (
   add_type ident_result decl_result (
+  add_type ident_dict decl_dict (
   add_type ident_list decl_list (
   add_type ident_array decl_array (
   add_type ident_exn decl_exn (
@@ -305,7 +315,7 @@ let common_initial_env add_type add_extension empty_env =
   add_type ident_extension_constructor decl_abstr (
   add_type ident_floatarray decl_abstr (
     add_type ident_promise decl_promise (
-      empty_env))))))))))))))))))))))))))
+      empty_env)))))))))))))))))))))))))))
 
 let build_initial_env add_type add_exception empty_env =
   let common = common_initial_env add_type add_exception empty_env in

jscomp/ml/predef.mli

@@ -29,6 +29,7 @@ val type_array: type_expr -> type_expr
 val type_list: type_expr -> type_expr
 val type_option: type_expr -> type_expr
 val type_result: type_expr -> type_expr -> type_expr
+val type_dict: type_expr -> type_expr
 
 val type_int64: type_expr
 val type_lazy_t: type_expr -> type_expr
@@ -47,6 +48,7 @@ val path_array: Path.t
 val path_list: Path.t
 val path_option: Path.t
 val path_result: Path.t
+val path_dict: Path.t
 
 val path_int64: Path.t
 val path_lazy_t: Path.t

jscomp/others/js_dict.res

@@ -25,7 +25,7 @@
 /*** Provides a simple key-value dictionary abstraction over native JavaScript objects */
 
 /** The dict type */
-type t<'a>
+type t<'a> = dict<'a>
 
 /** The key type, an alias of string */
 type key = string

jscomp/others/js_dict.resi

@@ -39,7 +39,7 @@ Dictionary type (ie an '{ }' JS object). However it is restricted to hold a
 single type; therefore values must have the same type. This Dictionary type is
 mostly used with the Js_json.t type.
 */
-type t<'a>
+type t<'a> = dict<'a>
 
 /**
   The type for dictionary keys. This means that dictionaries *must* use `string`s as their keys.

lib/es6/js_json.js

@@ -1,6 +1,5 @@
 
 
-import * as Caml_option from "./caml_option.js";
 
 var Kind = {};
 
@@ -75,7 +74,7 @@ function decodeNumber(json) {
 
 function decodeObject(json) {
   if (typeof json === "object" && !Array.isArray(json) && json !== null) {
-    return Caml_option.some(json);
+    return json;
   }
 
 }

lib/js/js_json.js

@@ -1,6 +1,5 @@
 'use strict';
 
-var Caml_option = require("./caml_option.js");
 
 var Kind = {};
 
@@ -75,7 +74,7 @@ function decodeNumber(json) {
 
 function decodeObject(json) {
   if (typeof json === "object" && !Array.isArray(json) && json !== null) {
-    return Caml_option.some(json);
+    return json;
   }
 
 }