Introduce F#-style binary operators (#7894)

* switch to F#-style binary operators

* fix dangling token selection

* add changelog

* fix migrations

Author: cometkim

CHANGELOG.md

@@ -14,6 +14,8 @@
 
 #### :boom: Breaking Change
 
+- Replace binary operators with F#-style `~~~`, `^^^`, `&&&`, `|||`. https://github.com/rescript-lang/rescript/pull/7894
+
 #### :eyeglasses: Spec Compliance
 
 #### :rocket: New Feature

compiler/ml/unified_ops.ml

@@ -208,7 +208,7 @@ let entries =
         };
     };
     {
-      path = builtin "~~";
+      path = builtin "~~~";
       name = "%bitnot";
       form = Unary;
       specialization =
@@ -221,20 +221,20 @@ let entries =
         };
     };
     {
-      path = builtin "&";
-      name = "%bitand";
+      path = builtin "|||";
+      name = "%bitor";
       form = Binary;
       specialization =
         {
-          int = Pandint;
+          int = Porint;
           bool = None;
           float = None;
-          bigint = Some Pandbigint;
+          bigint = Some Porbigint;
           string = None;
         };
     };
     {
-      path = builtin "^";
+      path = builtin "^^^";
       name = "%bitxor";
       form = Binary;
       specialization =
@@ -246,6 +246,19 @@ let entries =
           string = None;
         };
     };
+    {
+      path = builtin "&&&";
+      name = "%bitand";
+      form = Binary;
+      specialization =
+        {
+          int = Pandint;
+          bool = None;
+          float = None;
+          bigint = Some Pandbigint;
+          string = None;
+        };
+    };
   |]
 
 let index_by_path =

compiler/syntax/src/res_comments_table.ml

@@ -1496,7 +1496,7 @@ and walk_expression expr t comments =
                 {
                   txt =
                     Longident.Lident
-                      ("~+" | "~+." | "~-" | "~-." | "~~" | "not" | "!");
+                      ("~+" | "~+." | "~-" | "~-." | "~~~" | "not" | "!");
                 };
           };
         args = [(Nolabel, arg_expr)];
@@ -1517,7 +1517,8 @@ and walk_expression expr t comments =
                     Longident.Lident
                       ( ":=" | "||" | "&&" | "==" | "===" | "<" | ">" | "!="
                       | "!==" | "<=" | ">=" | "+" | "+." | "-" | "-." | "++"
-                      | "^" | "*" | "*." | "/" | "/." | "**" | "->" | "<>" );
+                      | "|||" | "^^^" | "&&&" | "*" | "*." | "/" | "/." | "**"
+                      | "->" | "<>" );
                 };
           };
         args = [(Nolabel, operand1); (Nolabel, operand2)];

compiler/syntax/src/res_core.ml

@@ -508,9 +508,12 @@ let make_unary_expr start_pos token_end token operand =
     }
   | (Minus | MinusDot), Pexp_constant (Pconst_float (n, m)) ->
     {operand with pexp_desc = Pexp_constant (Pconst_float (negate_string n, m))}
-  | (Token.Plus | PlusDot | Minus | MinusDot | Tilde), _ ->
+  | (Token.Plus | PlusDot | Minus | MinusDot | Bnot), _ ->
     let token_loc = mk_loc start_pos token_end in
-    let operator = "~" ^ Token.to_string token in
+    let token_string = Token.to_string token in
+    let operator =
+      if token_string.[0] = '~' then token_string else "~" ^ token_string
+    in
     Ast_helper.Exp.apply
       ~loc:(mk_loc start_pos operand.Parsetree.pexp_loc.loc_end)
       (Ast_helper.Exp.ident ~loc:token_loc
@@ -2292,7 +2295,7 @@ and parse_primary_expr ~operand ?(no_call = false) p =
 and parse_unary_expr p =
   let start_pos = p.Parser.start_pos in
   match p.Parser.token with
-  | (Minus | MinusDot | Plus | PlusDot | Bang | Tilde) as token ->
+  | (Minus | MinusDot | Plus | PlusDot | Bang | Bnot) as token ->
     Parser.leave_breadcrumb p Grammar.ExprUnary;
     let token_end = p.end_pos in
     Parser.next p;
@@ -5940,15 +5943,15 @@ and parse_polymorphic_variant_type_spec_hash ~attrs ~full p :
   let ident, loc = parse_hash_ident ~start_pos p in
   let rec loop p =
     match p.Parser.token with
-    | Band when full ->
+    | Ampersand when full ->
       Parser.next p;
       let row_field = parse_polymorphic_variant_type_args p in
       row_field :: loop p
     | _ -> []
   in
   let first_tuple, tag_contains_a_constant_empty_constructor =
     match p.Parser.token with
-    | Band when full ->
+    | Ampersand when full ->
       Parser.next p;
       ([parse_polymorphic_variant_type_args p], true)
     | Lparen -> ([parse_polymorphic_variant_type_args p], false)

compiler/syntax/src/res_grammar.ml

@@ -151,8 +151,9 @@ let is_atomic_typ_expr_start = function
 let is_expr_start = function
   | Token.Assert | At | Await | Backtick | Bang | Codepoint _ | False | Float _
   | For | Hash | If | Int _ | Lbrace | Lbracket | LessThan | Lident _ | List
-  | Lparen | Minus | MinusDot | Module | Percent | Plus | PlusDot | Tilde
-  | String _ | Switch | True | Try | Uident _ | Underscore (* _ => doThings() *)
+  | Lparen | Minus | MinusDot | Module | Percent | Plus | PlusDot | Bnot | Bor
+  | Bxor | Band | String _ | Switch | True | Try | Uident _
+  | Underscore (* _ => doThings() *)
   | While | Forwardslash | ForwardslashDot | Dict ->
     true
   | _ -> false

compiler/syntax/src/res_parens.ml

@@ -129,7 +129,6 @@ let binary_expr_operand ~is_lhs expr =
     | _ when Ast_uncurried.expr_is_uncurried_fun expr -> Parenthesized
     | expr when ParsetreeViewer.is_binary_expression expr -> Parenthesized
     | expr when ParsetreeViewer.is_ternary_expr expr -> Parenthesized
-    | expr when ParsetreeViewer.is_unary_bitnot_expression expr -> Parenthesized
     | {pexp_desc = Pexp_assert _} when is_lhs -> Parenthesized
     | _ when ParsetreeViewer.expr_is_await expr -> Parenthesized
     | {Parsetree.pexp_attributes = attrs} ->

compiler/syntax/src/res_parsetree_viewer.ml

@@ -267,19 +267,20 @@ let operator_precedence operator =
   | ":=" -> 1
   | "||" -> 2
   | "&&" -> 3
-  | "^" -> 4
-  | "&" -> 5
-  | "==" | "===" | "<" | ">" | "!=" | "<>" | "!==" | "<=" | ">=" -> 6
-  | "<<" | ">>" | ">>>" -> 7
-  | "+" | "+." | "-" | "-." | "++" -> 8
-  | "*" | "*." | "/" | "/." | "%" -> 9
-  | "**" -> 10
-  | "#" | "##" | "->" -> 11
+  | "|||" -> 4
+  | "^^^" -> 5
+  | "&&&" -> 6
+  | "==" | "===" | "<" | ">" | "!=" | "<>" | "!==" | "<=" | ">=" -> 7
+  | "<<" | ">>" | ">>>" -> 8
+  | "+" | "+." | "-" | "-." | "++" -> 9
+  | "*" | "*." | "/" | "/." | "%" -> 10
+  | "**" -> 11
+  | "#" | "##" | "->" -> 12
   | _ -> 0
 
 let is_unary_operator operator =
   match operator with
-  | "~+" | "~+." | "~-" | "~-." | "~~" | "not" -> true
+  | "~+" | "~+." | "~-" | "~-." | "~~~" | "not" -> true
   | _ -> false
 
 let is_unary_expression expr =
@@ -293,21 +294,11 @@ let is_unary_expression expr =
     true
   | _ -> false
 
-let is_unary_bitnot_expression expr =
-  match expr.pexp_desc with
-  | Pexp_apply
-      {
-        funct = {pexp_desc = Pexp_ident {txt = Longident.Lident "~~"}};
-        args = [(Nolabel, _arg)];
-      } ->
-    true
-  | _ -> false
-
 let is_binary_operator operator =
   match operator with
   | ":=" | "||" | "&&" | "==" | "===" | "<" | ">" | "!=" | "!==" | "<=" | ">="
   | "+" | "+." | "-" | "-." | "++" | "*" | "*." | "/" | "/." | "**" | "->"
-  | "<>" | "%" | "&" | "^" | "<<" | ">>" | ">>>" ->
+  | "<>" | "%" | "|||" | "^^^" | "&&&" | "<<" | ">>" | ">>>" ->
     true
   | _ -> false
 

compiler/syntax/src/res_parsetree_viewer.mli

@@ -66,7 +66,6 @@ val operator_precedence : string -> int
 
 val not_ghost_operator : string -> Location.t -> bool
 val is_unary_expression : Parsetree.expression -> bool
-val is_unary_bitnot_expression : Parsetree.expression -> bool
 val is_binary_operator : string -> bool
 val is_binary_expression : Parsetree.expression -> bool
 val is_rhs_binary_operator : string -> bool

compiler/syntax/src/res_printer.ml

@@ -3777,7 +3777,7 @@ and print_unary_expression ~state expr cmt_tbl =
       | "~+." -> "+."
       | "~-" -> "-"
       | "~-." -> "-."
-      | "~~" -> "~"
+      | "~~~" -> "~~~"
       | "not" -> "!"
       | _ -> assert false)
   in
@@ -5101,8 +5101,6 @@ and print_argument ~state (arg_lbl, arg) cmt_tbl =
       match Parens.expr expr with
       | Parenthesized -> add_parens doc
       | Braced braces -> print_braces doc expr braces
-      | Nothing when ParsetreeViewer.is_unary_bitnot_expression expr ->
-        add_parens doc
       | Nothing -> doc
     in
     let loc = {arg_loc with loc_end = expr.pexp_loc.loc_end} in

compiler/syntax/src/res_scanner.ml

@@ -756,9 +756,14 @@ let rec scan scanner =
     | '`' ->
       next scanner;
       Token.Backtick
-    | '~' ->
-      next scanner;
-      Token.Tilde
+    | '~' -> (
+      match (peek scanner, peek2 scanner) with
+      | '~', '~' ->
+        next3 scanner;
+        Token.Bnot
+      | _ ->
+        next scanner;
+        Token.Tilde)
     | '?' ->
       next scanner;
       Token.Question
@@ -830,24 +835,35 @@ let rec scan scanner =
         next scanner;
         Token.Percent)
     | '|' -> (
-      match peek scanner with
-      | '|' ->
+      match (peek scanner, peek2 scanner) with
+      | '|', '|' ->
+        next3 scanner;
+        Token.Bor
+      | '|', _ ->
         next2 scanner;
         Token.Lor
       | _ ->
         next scanner;
         Token.Bar)
     | '&' -> (
-      match peek scanner with
-      | '&' ->
+      match (peek scanner, peek2 scanner) with
+      | '&', '&' ->
+        next3 scanner;
+        Token.Band
+      | '&', _ ->
         next2 scanner;
         Token.Land
       | _ ->
         next scanner;
-        Token.Band)
-    | '^' ->
-      next scanner;
-      Token.Caret
+        Token.Ampersand)
+    | '^' -> (
+      match (peek scanner, peek2 scanner) with
+      | '^', '^' ->
+        next3 scanner;
+        Token.Bxor
+      | _ ->
+        next scanner;
+        Token.Caret)
     | ':' -> (
       match peek scanner with
       | '=' ->