AST: represent concatenation and (dis)equality operators just like in the syntax.

CHANGELOG.md

@@ -28,6 +28,7 @@
 - AST cleanup: Remove `@res.partial` attribute from the internal representation, and add a flag to untyped and typed ASTs instead. https://github.com/rescript-lang/rescript/pull/7238 https://github.com/rescript-lang/rescript/pull/7240
 - AST cleanup: Remove `structure_item_desc.Pstr_class`, `signature_item_desc.Psig_class`, `structure_item_desc.Pstr_class_type`, `signature_item_desc.Psig_class_type`, `structure_item_desc.Tstr_class`, `structure_item_desc.Tstr_class_type`, `signature_item_desc.Tsig_class`, `signature_item_desc.Tsig_class_type` from AST as it is unused. https://github.com/rescript-lang/rescript/pull/7242
 - AST cleanup: remove "|." and rename "|." to "->" in the internal representation for the pipe operator. https://github.com/rescript-lang/rescript/pull/7244
+- AST cleanup: represent concatenation (`++`) and (dis)equality operators (`==`, `===`, `!=`, `!==`) just like in the syntax. https://github.com/rescript-lang/rescript/pull/7248
 
 # 12.0.0-alpha.7
 

analysis/examples/larger-project/src/res_comments_table.res

@@ -1236,8 +1236,8 @@ and walkExpr = (expr, t, comments) => {
             ":="
             | "||"
             | "&&"
-            | "="
             | "=="
+            | "==="
             | "<"
             | ">"
             | "!="

analysis/src/Xform.ml

@@ -93,15 +93,15 @@ module IfThenElse = struct
                         {
                           pexp_desc =
                             Pexp_ident
-                              {txt = Longident.Lident (("=" | "<>") as op)};
+                              {txt = Longident.Lident (("==" | "!=") as op)};
                         };
                       args = [(Nolabel, arg1); (Nolabel, arg2)];
                     };
               },
               e1,
               Some e2 )
           when Loc.hasPos ~pos e.pexp_loc -> (
-          let e1, e2 = if op = "=" then (e1, e2) else (e2, e1) in
+          let e1, e2 = if op = "==" then (e1, e2) else (e2, e1) in
           let mkMatch ~arg ~pat =
             let cases =
               [

compiler/ml/ast_mapper_from0.ml

@@ -316,6 +316,27 @@ module E = struct
         | ( Pexp_ident ({txt = Longident.Lident "|."} as lid),
             [(Nolabel, _); (Nolabel, _)] ) ->
           {e with pexp_desc = Pexp_ident {lid with txt = Longident.Lident "->"}}
+        | ( Pexp_ident ({txt = Longident.Lident "^"} as lid),
+            [(Nolabel, _); (Nolabel, _)] ) ->
+          {e with pexp_desc = Pexp_ident {lid with txt = Longident.Lident "++"}}
+        | ( Pexp_ident ({txt = Longident.Lident "<>"} as lid),
+            [(Nolabel, _); (Nolabel, _)] ) ->
+          {e with pexp_desc = Pexp_ident {lid with txt = Longident.Lident "!="}}
+        | ( Pexp_ident ({txt = Longident.Lident "!="} as lid),
+            [(Nolabel, _); (Nolabel, _)] ) ->
+          {
+            e with
+            pexp_desc = Pexp_ident {lid with txt = Longident.Lident "!=="};
+          }
+        | ( Pexp_ident ({txt = Longident.Lident "="} as lid),
+            [(Nolabel, _); (Nolabel, _)] ) ->
+          {e with pexp_desc = Pexp_ident {lid with txt = Longident.Lident "=="}}
+        | ( Pexp_ident ({txt = Longident.Lident "=="} as lid),
+            [(Nolabel, _); (Nolabel, _)] ) ->
+          {
+            e with
+            pexp_desc = Pexp_ident {lid with txt = Longident.Lident "==="};
+          }
         | _ -> e
       in
       let process_partial_app_attribute attrs =

compiler/ml/ast_mapper_to0.ml

@@ -327,6 +327,21 @@ module E = struct
         | ( Pexp_ident ({txt = Longident.Lident "->"} as lid),
             [(Nolabel, _); (Nolabel, _)] ) ->
           {e with pexp_desc = Pexp_ident {lid with txt = Longident.Lident "|."}}
+        | ( Pexp_ident ({txt = Longident.Lident "++"} as lid),
+            [(Nolabel, _); (Nolabel, _)] ) ->
+          {e with pexp_desc = Pexp_ident {lid with txt = Longident.Lident "^"}}
+        | ( Pexp_ident ({txt = Longident.Lident "!="} as lid),
+            [(Nolabel, _); (Nolabel, _)] ) ->
+          {e with pexp_desc = Pexp_ident {lid with txt = Longident.Lident "<>"}}
+        | ( Pexp_ident ({txt = Longident.Lident "!=="} as lid),
+            [(Nolabel, _); (Nolabel, _)] ) ->
+          {e with pexp_desc = Pexp_ident {lid with txt = Longident.Lident "!="}}
+        | ( Pexp_ident ({txt = Longident.Lident "==="} as lid),
+            [(Nolabel, _); (Nolabel, _)] ) ->
+          {e with pexp_desc = Pexp_ident {lid with txt = Longident.Lident "=="}}
+        | ( Pexp_ident ({txt = Longident.Lident "=="} as lid),
+            [(Nolabel, _); (Nolabel, _)] ) ->
+          {e with pexp_desc = Pexp_ident {lid with txt = Longident.Lident "="}}
         | _ -> e
       in
       let attrs =

compiler/ml/error_message_utils.ml

@@ -55,6 +55,7 @@ let error_expected_type_text ppf type_clash_context =
       operator
   | Some FunctionReturn ->
     fprintf ppf "But this function is expecting you to return:"
+  | Some StringConcat -> fprintf ppf "But string concatenation is expecting:"
   | _ -> fprintf ppf "But it's expected to have type:"
 
 let is_record_type ~extract_concrete_typedecl ~env ty =
@@ -204,7 +205,7 @@ let type_clash_context_from_function sexp sfunct =
   in
   match sfunct.Parsetree.pexp_desc with
   | Pexp_ident
-      {txt = Lident ("=" | "==" | "<>" | "!=" | ">" | ">=" | "<" | "<=")} ->
+      {txt = Lident ("==" | "===" | "!=" | "!==" | ">" | ">=" | "<" | "<=")} ->
     Some ComparisonOperator
   | Pexp_ident {txt = Lident "++"} -> Some StringConcat
   | Pexp_ident {txt = Lident (("/." | "*." | "+." | "-.") as operator)} ->

compiler/syntax/src/res_comments_table.ml

@@ -1338,7 +1338,7 @@ and walk_expression expr t comments =
                 {
                   txt =
                     Longident.Lident
-                      ( ":=" | "||" | "&&" | "=" | "==" | "<" | ">" | "!="
+                      ( ":=" | "||" | "&&" | "==" | "===" | "<" | ">" | "!="
                       | "!==" | "<=" | ">=" | "|>" | "+" | "+." | "-" | "-."
                       | "++" | "^" | "*" | "*." | "/" | "/." | "**" | "->"
                       | "<>" );

compiler/syntax/src/res_core.ml

@@ -391,16 +391,11 @@ let build_longident words =
 
 let make_infix_operator (p : Parser.t) token start_pos end_pos =
   let stringified_token =
-    if token = Token.PlusPlus then "^"
-    else if token = Token.BangEqual then "<>"
-    else if token = Token.BangEqualEqual then "!="
-    else if token = Token.Equal then (
+    if token = Token.Equal then (
       (* TODO: could have a totally different meaning like x->fooSet(y)*)
       Parser.err ~start_pos ~end_pos p
         (Diagnostics.message "Did you mean `==` here?");
       "=")
-    else if token = Token.EqualEqual then "="
-    else if token = Token.EqualEqualEqual then "=="
     else Token.to_string token
   in
   let loc = mk_loc start_pos end_pos in
@@ -2327,7 +2322,7 @@ and parse_template_expr ?prefix p =
   in
 
   let hidden_operator =
-    let op = Location.mknoloc (Longident.Lident "^") in
+    let op = Location.mknoloc (Longident.Lident "++") in
     Ast_helper.Exp.ident op
   in
   let concat (e1 : Parsetree.expression) (e2 : Parsetree.expression) =

compiler/syntax/src/res_parens.ml

@@ -162,7 +162,7 @@ let rhs_binary_expr_operand parent_operator rhs =
         args = [(_, _left); (_, _right)];
       }
     when ParsetreeViewer.is_binary_operator operator
-         && not (operator_loc.loc_ghost && operator = "^") ->
+         && not (operator_loc.loc_ghost && operator = "++") ->
     let prec_parent = ParsetreeViewer.operator_precedence parent_operator in
     let prec_child = ParsetreeViewer.operator_precedence operator in
     prec_parent == prec_child
@@ -180,7 +180,7 @@ let flatten_operand_rhs parent_operator rhs =
         args = [(_, _left); (_, _right)];
       }
     when ParsetreeViewer.is_binary_operator operator
-         && not (operator_loc.loc_ghost && operator = "^") ->
+         && not (operator_loc.loc_ghost && operator = "++") ->
     let prec_parent = ParsetreeViewer.operator_precedence parent_operator in
     let prec_child = ParsetreeViewer.operator_precedence operator in
     prec_parent >= prec_child || rhs.pexp_attributes <> []

compiler/syntax/src/res_parsetree_viewer.ml

@@ -270,8 +270,8 @@ let operator_precedence operator =
   | ":=" -> 1
   | "||" -> 2
   | "&&" -> 3
-  | "=" | "==" | "<" | ">" | "!=" | "<>" | "!==" | "<=" | ">=" | "|>" -> 4
-  | "+" | "+." | "-" | "-." | "^" -> 5
+  | "==" | "===" | "<" | ">" | "!=" | "<>" | "!==" | "<=" | ">=" | "|>" -> 4
+  | "+" | "+." | "-" | "-." | "++" -> 5
   | "*" | "*." | "/" | "/." | "%" -> 6
   | "**" -> 7
   | "#" | "##" | "->" -> 8
@@ -296,9 +296,9 @@ let is_unary_expression expr =
 (* TODO: tweak this to check for ghost ^ as template literal *)
 let is_binary_operator operator =
   match operator with
-  | ":=" | "||" | "&&" | "=" | "==" | "<" | ">" | "!=" | "!==" | "<=" | ">="
-  | "|>" | "+" | "+." | "-" | "-." | "^" | "*" | "*." | "/" | "/." | "**" | "->"
-  | "<>" | "%" ->
+  | ":=" | "||" | "&&" | "==" | "===" | "<" | ">" | "!=" | "!==" | "<=" | ">="
+  | "|>" | "+" | "+." | "-" | "-." | "++" | "*" | "*." | "/" | "/." | "**"
+  | "->" | "<>" | "%" ->
     true
   | _ -> false
 
@@ -314,14 +314,14 @@ let is_binary_expression expr =
         args = [(Nolabel, _operand1); (Nolabel, _operand2)];
       }
     when is_binary_operator operator
-         && not (operator_loc.loc_ghost && operator = "^")
+         && not (operator_loc.loc_ghost && operator = "++")
          (* template literal *) ->
     true
   | _ -> false
 
 let is_equality_operator operator =
   match operator with
-  | "=" | "==" | "<>" | "!=" -> true
+  | "==" | "===" | "!=" | "!==" -> true
   | _ -> false
 
 let is_rhs_binary_operator operator =
@@ -643,7 +643,7 @@ let is_template_literal expr =
   match expr.pexp_desc with
   | Pexp_apply
       {
-        funct = {pexp_desc = Pexp_ident {txt = Longident.Lident "^"}};
+        funct = {pexp_desc = Pexp_ident {txt = Longident.Lident "++"}};
         args = [(Nolabel, _); (Nolabel, _)];
       }
     when has_template_literal_attr expr.pexp_attributes ->

compiler/syntax/src/res_printer.ml

@@ -3557,7 +3557,7 @@ and print_template_literal ~state expr cmt_tbl =
     match expr.pexp_desc with
     | Pexp_apply
         {
-          funct = {pexp_desc = Pexp_ident {txt = Longident.Lident "^"}};
+          funct = {pexp_desc = Pexp_ident {txt = Longident.Lident "++"}};
           args = [(Nolabel, arg1); (Nolabel, arg2)];
         } ->
       let lhs = walk_expr arg1 in
@@ -3662,15 +3662,6 @@ and print_unary_expression ~state expr cmt_tbl =
 
 and print_binary_expression ~state (expr : Parsetree.expression) cmt_tbl =
   let print_binary_operator ~inline_rhs operator =
-    let operator_txt =
-      match operator with
-      | "^" -> "++"
-      | "=" -> "=="
-      | "==" -> "==="
-      | "<>" -> "!="
-      | "!=" -> "!=="
-      | txt -> txt
-    in
     let spacing_before_operator =
       if operator = "->" then Doc.soft_line
       else if operator = "|>" then Doc.line
@@ -3683,7 +3674,7 @@ and print_binary_expression ~state (expr : Parsetree.expression) cmt_tbl =
       else Doc.line
     in
     Doc.concat
-      [spacing_before_operator; Doc.text operator_txt; spacing_after_operator]
+      [spacing_before_operator; Doc.text operator; spacing_after_operator]
   in
   let print_operand ~is_lhs ~is_multiline expr parent_operator =
     let rec flatten ~is_lhs ~is_multiline expr parent_operator =
@@ -3800,7 +3791,7 @@ and print_binary_expression ~state (expr : Parsetree.expression) cmt_tbl =
         match expr.pexp_desc with
         | Pexp_apply
             {
-              funct = {pexp_desc = Pexp_ident {txt = Longident.Lident "^"; loc}};
+              funct = {pexp_desc = Pexp_ident {txt = Longident.Lident "++"; loc}};
               args = [(Nolabel, _); (Nolabel, _)];
             }
           when loc.loc_ghost ->

runtime/Pervasives.res

@@ -55,17 +55,17 @@ external mod: ('a, 'a) => 'a = "%mod"
 /* Comparisons */
 /* Note: Later comparisons will be converted to unified operations too */
 
-external \"=": ('a, 'a) => bool = "%equal"
-external \"<>": ('a, 'a) => bool = "%notequal"
+external \"==": ('a, 'a) => bool = "%equal"
+external \"!=": ('a, 'a) => bool = "%notequal"
 external \"<": ('a, 'a) => bool = "%lessthan"
 external \">": ('a, 'a) => bool = "%greaterthan"
 external \"<=": ('a, 'a) => bool = "%lessequal"
 external \">=": ('a, 'a) => bool = "%greaterequal"
 external compare: ('a, 'a) => int = "%compare"
 external min: ('a, 'a) => 'a = "%min"
 external max: ('a, 'a) => 'a = "%max"
-external \"==": ('a, 'a) => bool = "%eq"
-external \"!=": ('a, 'a) => bool = "%noteq"
+external \"===": ('a, 'a) => bool = "%eq"
+external \"!==": ('a, 'a) => bool = "%noteq"
 
 /* Boolean operations */
 
@@ -230,7 +230,7 @@ let classify_float = (x: float): fpclass =>
 
 /* String and byte sequence operations -- more in modules String and Bytes */
 
-external \"^": (string, string) => string = "%string_concat"
+external \"++": (string, string) => string = "%string_concat"
 
 /* Character operations -- more in module Char */
 

runtime/Pervasives_mini.res

@@ -34,17 +34,17 @@ external mod: (int, int) => int = "%modint"
 /* Comparisons */
 /* Note: Later comparisons will be converted to unified operations too */
 
-external \"=": ('a, 'a) => bool = "%equal"
-external \"<>": ('a, 'a) => bool = "%notequal"
+external \"==": ('a, 'a) => bool = "%equal"
+external \"!=": ('a, 'a) => bool = "%notequal"
 external \"<": ('a, 'a) => bool = "%lessthan"
 external \">": ('a, 'a) => bool = "%greaterthan"
 external \"<=": ('a, 'a) => bool = "%lessequal"
 external \">=": ('a, 'a) => bool = "%greaterequal"
 external compare: ('a, 'a) => int = "%compare"
 external min: ('a, 'a) => 'a = "%min"
 external max: ('a, 'a) => 'a = "%max"
-external \"==": ('a, 'a) => bool = "%eq"
-external \"!=": ('a, 'a) => bool = "%noteq"
+external \"===": ('a, 'a) => bool = "%eq"
+external \"!==": ('a, 'a) => bool = "%noteq"
 
 /* Boolean operations */
 
@@ -78,7 +78,7 @@ external \"/.": (float, float) => float = "%divfloat"
 
 /* String operations */
 
-external \"^": (string, string) => string = "%string_concat"
+external \"++": (string, string) => string = "%string_concat"
 
 /* Unit operations */
 

tests/build_tests/super_errors/expected/primitives2.res.expected

@@ -7,6 +7,6 @@
   3 │ 
 
   This has type: int
-  But this function argument is expecting: string
+  But string concatenation is expecting: string
 
   You can convert int to string with Belt.Int.toString.

tests/build_tests/super_errors/expected/unicode_location.res.expected

@@ -8,6 +8,6 @@
   3 │ 
 
   This has type: int
-  But this function argument is expecting: string
+  But string concatenation is expecting: string
 
   You can convert int to string with Belt.Int.toString.

tests/syntax_tests/data/parsing/errors/expressions/expected/block.res.txt

@@ -75,7 +75,7 @@ let findThreadByIdLinearScan [arity:2]~threads:((threads)[@res.namedArgLoc ])
                | Group { id } -> id
                | Unknown { id } ->
                    (unknown.id -> Js.String.make) -> FBID.ofStringUnsafe in
-             thisId == id)
+             thisId === id)
            [@res.braces ])))
   [@res.braces ])
 let x = ((loop 0 (Nil -> (push doc)))[@res.braces ])

tests/syntax_tests/data/parsing/errors/structure/expected/gh16B.res.txt

@@ -16,15 +16,15 @@ let wss = Server.make { port = 82 }
 let address = wss -> Server.address
 let log [arity:1]msg =
   Js.log
-    (((((({js|> Server: |js})[@res.template ]) ^ msg)[@res.template ]) ^
+    (((((({js|> Server: |js})[@res.template ]) ++ msg)[@res.template ]) ++
         (({js||js})[@res.template ]))[@res.template ])
 ;;log
-    (((((((((((((({js|Running on: |js})[@res.template ]) ^ address.address)
-                [@res.template ]) ^ (({js|:|js})[@res.template ]))
-              [@res.template ]) ^ (address.port -> string_of_int))
-            [@res.template ]) ^ (({js| (|js})[@res.template ]))
-          [@res.template ]) ^ address.family)
-        [@res.template ]) ^ (({js|)|js})[@res.template ]))[@res.template ])
+    (((((((((((((({js|Running on: |js})[@res.template ]) ++ address.address)
+                [@res.template ]) ++ (({js|:|js})[@res.template ]))
+              [@res.template ]) ++ (address.port -> string_of_int))
+            [@res.template ]) ++ (({js| (|js})[@res.template ]))
+          [@res.template ]) ++ address.family)
+        [@res.template ]) ++ (({js|)|js})[@res.template ]))[@res.template ])
 module ClientSet =
   struct
     module T =

tests/syntax_tests/data/parsing/errors/structure/expected/letBinding.res.txt

@@ -99,7 +99,7 @@
 
 let rightResource =
   (ur.resources).find
-    (fun [arity:1]r -> r.account_id == ((connection.left).account).id)
+    (fun [arity:1]r -> r.account_id === ((connection.left).account).id)
 let x = ((let field = p -> parseFieldDeclaration in field)[@res.braces ])
 let t = ((let (_, _, token) = scanner -> scan in token)[@res.braces ])
 let (keyTable : int Belt.Map.String.t) = [%rescript.exprhole ]

tests/syntax_tests/data/parsing/grammar/expressions/expected/arrow.res.txt

@@ -52,9 +52,9 @@ let f [arity:4]~a:((a)[@res.namedArgLoc ][@attr ])  ((b)[@attrOnB ])
 let f [arity:1]list = list ()
 ;;match colour with
   | Red when
-      (l = l') ||
+      (l == l') ||
         (Clflags.classic.contents &&
-           ((l = Nolabel) && (not (is_optional l'))))
+           ((l == Nolabel) && (not (is_optional l'))))
       -> (t1, t2)
   | _ -> ()
 let arr =

tests/syntax_tests/data/parsing/grammar/expressions/expected/async.res.txt

@@ -1,6 +1,6 @@
 let greetUser async [arity:1]userId =
   ((let name = ((getUserName userId)[@res.await ]) in
-    ({js|Hello |js} ^ name) ^ {js|!|js})
+    ({js|Hello |js} ++ name) ++ {js|!|js})
   [@res.braces ])
 ;;async fun [arity:1]() -> 123
 let fetch = ((async fun [arity:1]url -> browserFetch url)[@res.braces ])