Cleanup pipe: remove |.u and change "|." to "->" to represent pipe. (#7244)

* Cleanup pipe: remove `|.u` which is effectively treated the same as `|.`.

* Rename binary operator "|." to "->" in the internal representation.

* Add ppx test for "->" representation.

* Update CHANGELOG.md

* Map between `->` and `|.` in the ppx conversion.

Author: cristianoc

CHANGELOG.md

@@ -27,6 +27,7 @@
 - AST cleanup: Remove `expression_desc.Pexp_new`, `expression_desc.Pexp_setinstvar`, `expression_desc.Pexp_override`, `expression_desc.Pexp_poly`, `exp_extra.Texp_poly`, `expression_desc.Texp_new`, `expression_desc.Texp_setinstvar`, `expression_desc.Texp_override` & `expression_desc.Texp_instvar` from AST as it is unused. https://github.com/rescript-lang/rescript/pull/7239
 - 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
 
 # 12.0.0-alpha.7
 

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

@@ -1256,7 +1256,7 @@ and walkExpr = (expr, t, comments) => {
             | "/"
             | "/."
             | "**"
-            | "|."
+            | "->"
             | "<>",
           ),
         }),

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

@@ -270,7 +270,7 @@ let operatorPrecedence = operator =>
   | "+" | "+." | "-" | "-." | "^" => 5
   | "*" | "*." | "/" | "/." => 6
   | "**" => 7
-  | "#" | "##" | "|." => 8
+  | "#" | "##" | "->" => 8
   | _ => 0
   }
 
@@ -312,7 +312,7 @@ let isBinaryOperator = operator =>
   | "/"
   | "/."
   | "**"
-  | "|."
+  | "->"
   | "<>" => true
   | _ => false
   }
@@ -649,15 +649,15 @@ let isSinglePipeExpr = expr => {
   let isPipeExpr = expr =>
     switch expr.pexp_desc {
     | Pexp_apply(
-        {pexp_desc: Pexp_ident({txt: Longident.Lident("|." | "|>")})},
+        {pexp_desc: Pexp_ident({txt: Longident.Lident("->" | "|>")})},
         list{(Nolabel, _operand1), (Nolabel, _operand2)},
       ) => true
     | _ => false
     }
 
   switch expr.pexp_desc {
   | Pexp_apply(
-      {pexp_desc: Pexp_ident({txt: Longident.Lident("|." | "|>")})},
+      {pexp_desc: Pexp_ident({txt: Longident.Lident("->" | "|>")})},
       list{(Nolabel, operand1), (Nolabel, _operand2)},
     ) if !isPipeExpr(operand1) => true
   | _ => false

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

@@ -3495,7 +3495,6 @@ and printUnaryExpression = (expr, cmtTbl) => {
 and printBinaryExpression = (expr: Parsetree.expression, cmtTbl) => {
   let printBinaryOperator = (~inlineRhs, operator) => {
     let operatorTxt = switch operator {
-    | "|." => "->"
     | "^" => "++"
     | "=" => "=="
     | "==" => "==="

analysis/src/CompletionFrontEnd.ml

@@ -218,7 +218,7 @@ let rec exprToContextPathInner (e : Parsetree.expression) =
          (match exprs with
          | [] -> None
          | exp :: _ -> exprToContextPath exp))
-  | Pexp_ident {txt = Lident ("|." | "|.u")} -> None
+  | Pexp_ident {txt = Lident "->"} -> None
   | Pexp_ident {txt; loc} ->
     Some
       (CPId {path = Utils.flattenLongIdent txt; completionContext = Value; loc})
@@ -258,7 +258,7 @@ let rec exprToContextPathInner (e : Parsetree.expression) =
       {
         funct =
           {
-            pexp_desc = Pexp_ident {txt = Lident ("|." | "|.u")};
+            pexp_desc = Pexp_ident {txt = Lident "->"};
             pexp_loc;
             pexp_attributes;
           };
@@ -275,7 +275,7 @@ let rec exprToContextPathInner (e : Parsetree.expression) =
       }
   | Pexp_apply
       {
-        funct = {pexp_desc = Pexp_ident {txt = Lident ("|." | "|.u")}};
+        funct = {pexp_desc = Pexp_ident {txt = Lident "->"}};
         args =
           [
             (_, lhs); (_, {pexp_desc = Pexp_ident id; pexp_loc; pexp_attributes});
@@ -328,15 +328,15 @@ let completePipeChain (exp : Parsetree.expression) =
      Example: someArray->Js.Array2.map(v => v + 2)-> *)
   | Pexp_apply
       {
-        funct = {pexp_desc = Pexp_ident {txt = Lident ("|." | "|.u")}};
+        funct = {pexp_desc = Pexp_ident {txt = Lident "->"}};
         args = [_; (_, {pexp_desc = Pexp_apply {funct = d}})];
       } ->
     exprToContextPath exp |> Option.map (fun ctxPath -> (ctxPath, d.pexp_loc))
     (* When the left side of the pipe we're completing is an identifier application.
        Example: someArray->filterAllTheGoodStuff-> *)
   | Pexp_apply
       {
-        funct = {pexp_desc = Pexp_ident {txt = Lident ("|." | "|.u")}};
+        funct = {pexp_desc = Pexp_ident {txt = Lident "->"}};
         args = [_; (_, {pexp_desc = Pexp_ident _; pexp_loc})];
       } ->
     exprToContextPath exp |> Option.map (fun ctxPath -> (ctxPath, pexp_loc))
@@ -1113,8 +1113,7 @@ let completionWithParser1 ~currentFile ~debug ~offset ~path ~posCursor
       resetCurrentCtxPath oldCtxPath
     | Pexp_apply
         {
-          funct =
-            {pexp_desc = Pexp_ident {txt = Lident ("|." | "|.u"); loc = opLoc}};
+          funct = {pexp_desc = Pexp_ident {txt = Lident "->"; loc = opLoc}};
           args =
             [
               (_, lhs);
@@ -1292,7 +1291,7 @@ let completionWithParser1 ~currentFile ~debug ~offset ~path ~posCursor
           else iterateJsxProps ~iterator jsxProps
         | Pexp_apply
             {
-              funct = {pexp_desc = Pexp_ident {txt = Lident ("|." | "|.u")}};
+              funct = {pexp_desc = Pexp_ident {txt = Lident "->"}};
               args =
                 [
                   (_, lhs);
@@ -1304,19 +1303,15 @@ let completionWithParser1 ~currentFile ~debug ~offset ~path ~posCursor
           setPipeResult ~lhs ~id |> ignore
         | Pexp_apply
             {
-              funct =
-                {
-                  pexp_desc =
-                    Pexp_ident {txt = Lident ("|." | "|.u"); loc = opLoc};
-                };
+              funct = {pexp_desc = Pexp_ident {txt = Lident "->"; loc = opLoc}};
               args = [(_, lhs); _];
             }
           when Loc.end_ opLoc = posCursor ->
           if Debug.verbose () then print_endline "[expr_iter] Case foo->";
           setPipeResult ~lhs ~id:"" |> ignore
         | Pexp_apply
             {
-              funct = {pexp_desc = Pexp_ident {txt = Lident ("|." | "|.u")}};
+              funct = {pexp_desc = Pexp_ident {txt = Lident "->"}};
               args = [_; (_, {pexp_desc = Pexp_apply {funct = funExpr; args}})];
             }
           when (* Normally named arg completion fires when the cursor is right after the expression.
@@ -1352,7 +1347,7 @@ let completionWithParser1 ~currentFile ~debug ~offset ~path ~posCursor
           | Some argCompletable -> setResult argCompletable)
         | Pexp_apply
             {
-              funct = {pexp_desc = Pexp_ident {txt = Lident ("|." | "|.u")}};
+              funct = {pexp_desc = Pexp_ident {txt = Lident "->"}};
               args = [_; _];
             } ->
           (* Ignore any other pipe. *)

analysis/src/SignatureHelp.ml

@@ -365,7 +365,7 @@ let signatureHelp ~path ~pos ~currentFile ~debug ~allowForConstructorPayloads =
          pexp_desc =
            Pexp_apply
              {
-               funct = {pexp_desc = Pexp_ident {txt = Lident ("|." | "|.u")}};
+               funct = {pexp_desc = Pexp_ident {txt = Lident "->"}};
                args =
                  [
                    _;

compiler/frontend/ast_exp_apply.ml

@@ -69,11 +69,11 @@ let view_as_app (fn : exp) (s : string list) : app_pattern option =
     Some {op; loc = fn.pexp_loc; args = check_and_discard args}
   | _ -> None
 
-let infix_ops = ["|."; "|.u"; "#="; "##"]
+let infix_ops = ["->"; "#="; "##"]
 
 let app_exp_mapper (e : exp) (self : Bs_ast_mapper.mapper) : exp =
   match view_as_app e infix_ops with
-  | Some {op = "|." | "|.u"; args = [a_; f_]; loc} -> (
+  | Some {op = "->"; args = [a_; f_]; loc} -> (
     (*
         a |. f
         a |. f b c [@bs]  --> f a b c [@bs]
@@ -193,7 +193,7 @@ let app_exp_mapper (e : exp) (self : Bs_ast_mapper.mapper) : exp =
           } ->
         gen_assignment obj name name_loc
       | _ -> Location.raise_errorf ~loc "invalid #= assignment"))
-  | Some {op = "|."; loc} ->
+  | Some {op = "->"; loc} ->
     Location.raise_errorf ~loc
       "invalid |. syntax, it can only be used as binary operator"
   | Some {op = "##"; loc} ->

compiler/ml/ast_mapper_from0.ml

@@ -311,6 +311,13 @@ module E = struct
         (sub.pat sub p) (sub.expr sub e)
     | Pexp_function _ -> assert false
     | Pexp_apply (e, l) ->
+      let e =
+        match (e.pexp_desc, l) with
+        | ( 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 =
         let rec process partial_app acc attrs =
           match attrs with

compiler/ml/ast_mapper_to0.ml

@@ -321,12 +321,20 @@ module E = struct
           ~attrs:(arity_to_attributes arity)
           (Location.mkloc (Longident.Lident "Function$") e.pexp_loc)
           (Some e))
-    | Pexp_apply {funct = e; args = l; partial} ->
+    | Pexp_apply {funct = e; args; partial} ->
+      let e =
+        match (e.pexp_desc, args) with
+        | ( Pexp_ident ({txt = Longident.Lident "->"} as lid),
+            [(Nolabel, _); (Nolabel, _)] ) ->
+          {e with pexp_desc = Pexp_ident {lid with txt = Longident.Lident "|."}}
+        | _ -> e
+      in
       let attrs =
         if partial then (Location.mknoloc "res.partial", Pt.PStr []) :: attrs
         else []
       in
-      apply ~loc ~attrs (sub.expr sub e) (List.map (map_snd (sub.expr sub)) l)
+      apply ~loc ~attrs (sub.expr sub e)
+        (List.map (map_snd (sub.expr sub)) args)
     | Pexp_match (e, pel) ->
       match_ ~loc ~attrs (sub.expr sub e) (sub.cases sub pel)
     | Pexp_try (e, pel) -> try_ ~loc ~attrs (sub.expr sub e) (sub.cases sub pel)

compiler/ml/env.ml

@@ -1624,7 +1624,7 @@ and check_value_name name loc =
   (* Note: we could also check here general validity of the
      identifier, to protect against bad identifiers forged by -pp or
      -ppx preprocessors. *)
-  if name = "|." then raise (Error (Illegal_value_name (loc, name)))
+  if name = "->" then raise (Error (Illegal_value_name (loc, name)))
   else if String.length name > 0 && name.[0] = '#' then
     for i = 1 to String.length name - 1 do
       if name.[i] = '#' then raise (Error (Illegal_value_name (loc, name)))