refactor: move [Dialect] to [Dune_lang] (#10819)

Signed-off-by: Rudi Grinberg <me@rgrinberg.com>

bin/describe/describe_pp.ml

@@ -1,4 +1,5 @@
 open Import
+module Dialect = Dune_lang.Dialect
 
 let dialect_and_ml_kind file =
   let open Memo.O in
@@ -8,7 +9,7 @@ let dialect_and_ml_kind file =
   in
   let+ project = Source_tree.root () >>| Source_tree.Dir.project in
   let dialects = Dune_project.dialects project in
-  match Dune_rules.Dialect.DB.find_by_extension dialects ext with
+  match Dialect.DB.find_by_extension dialects ext with
   | None -> User_error.raise [ Pp.textf "unsupported extension: %s" ext ]
   | Some x -> x
 ;;
@@ -30,13 +31,12 @@ let execute_pp_action ~sctx file pp_file dump_file =
     let* action, _observing_facts =
       let* loc, action =
         let+ dialect, ml_kind = dialect_and_ml_kind file in
-        match Dune_rules.Dialect.print_ast dialect ml_kind with
+        match Dialect.print_ast dialect ml_kind with
         | Some print_ast -> print_ast
         | None ->
           (* fall back to the OCaml print_ast function, known to exist, if one
              doesn't exist for this dialect. *)
-          Dune_rules.Dialect.print_ast Dune_rules.Dialect.ocaml ml_kind
-          |> Option.value_exn
+          Dialect.print_ast Dialect.ocaml ml_kind |> Option.value_exn
       in
       let build =
         let open Action_builder.O in

src/dune_rules/dialect.ml → src/dune_lang/dialect.ml

@@ -1,5 +1,5 @@
-open Import
-module Action = Dune_lang.Action
+open Stdune
+open Dune_sexp
 module Ml_kind = Ocaml.Ml_kind
 module Cm_kind = Ocaml.Cm_kind
 module Mode = Ocaml.Mode
@@ -15,7 +15,7 @@ module File_kind = struct
     }
 
   let encode { kind; extension; preprocess; format; print_ast; merlin_reader } =
-    let open Dune_lang.Encoder in
+    let open Encoder in
     let kind =
       string
       @@
@@ -67,7 +67,7 @@ let to_dyn { name; file_kinds } =
 ;;
 
 let encode { name; file_kinds } =
-  let open Dune_lang.Encoder in
+  let open Encoder in
   let open Option.O in
   let file_kind_stanzas =
     List.filter_map Ml_kind.all ~f:(fun kind ->
@@ -79,7 +79,7 @@ let encode { name; file_kinds } =
 ;;
 
 let decode =
-  let open Dune_lang.Decoder in
+  let open Dune_sexp.Decoder in
   let kind kind =
     let+ loc, extension = field "extension" (located extension)
     and+ preprocess = field_o "preprocess" (located Action.decode_dune_file)
@@ -91,7 +91,7 @@ let decode =
     and+ merlin_reader =
       field_o
         "merlin_reader"
-        (Dune_lang.Syntax.since Stanza.syntax (3, 16) >>> located (repeat1 string))
+        (Syntax.since Stanza.syntax (3, 16) >>> located (repeat1 string))
     and+ syntax_ver = Syntax.get_exn Stanza.syntax in
     let ver = 3, 9 in
     if syntax_ver < ver && Option.is_some (String.index_from extension 1 '.')
@@ -105,7 +105,7 @@ let decode =
      and+ loc = loc
      and+ impl = field_o "implementation" (fields (kind Ml_kind.Impl))
      and+ intf = field_o "interface" (fields (kind Ml_kind.Intf))
-     and+ version = Dune_lang.Syntax.get_exn Stanza.syntax in
+     and+ version = Syntax.get_exn Stanza.syntax in
      let dialect_kind_optional_since = 3, 9 in
      if version < dialect_kind_optional_since
      then (
@@ -387,5 +387,5 @@ module DB = struct
 
   let to_dyn { by_name; _ } = String.Map.to_dyn to_dyn by_name
   let builtin = of_list [ ocaml; reason ]
-  let is_default t = phys_equal t builtin
+  let is_default t = t == builtin
 end

src/dune_rules/dialect.mli → src/dune_lang/dialect.mli

@@ -1,4 +1,5 @@
-open Import
+open Stdune
+open Dune_sexp
 open Ocaml
 
 (** Dialects
@@ -23,12 +24,12 @@ type t
 
 val name : t -> string
 val to_dyn : t -> Dyn.t
-val encode : t Dune_lang.Encoder.t
-val decode : t Dune_lang.Decoder.t
+val encode : t Encoder.t
+val decode : t Decoder.t
 val extension : t -> Ml_kind.t -> Filename.Extension.t option
-val preprocess : t -> Ml_kind.t -> (Loc.t * Dune_lang.Action.t) option
-val format : t -> Ml_kind.t -> (Loc.t * Dune_lang.Action.t * string list) option
-val print_ast : t -> Ml_kind.t -> (Loc.t * Dune_lang.Action.t) option
+val preprocess : t -> Ml_kind.t -> (Loc.t * Action.t) option
+val format : t -> Ml_kind.t -> (Loc.t * Action.t * string list) option
+val print_ast : t -> Ml_kind.t -> (Loc.t * Action.t) option
 val ocaml : t
 val reason : t
 val rescript : t

src/dune_lang/dune_lang.ml

@@ -41,3 +41,4 @@ module Package_info = Package_info
 module Section = Section
 module Package = Package
 module Dune_project_name = Dune_project_name
+module Dialect = Dialect

src/dune_rules/dune_rules.ml

@@ -61,7 +61,6 @@ module Dune_project = Dune_project
 module Source_tree = Source_tree
 module Source_dir_status = Source_dir_status
 module Dune_file0 = Dune_file0
-module Dialect = Dialect
 module Private_context = Private_context
 module Odoc = Odoc
 module Library = Library

src/dune_rules/import.ml

@@ -101,6 +101,7 @@ include struct
   module Package_constraint = Package_constraint
   module Dune_project_name = Dune_project_name
   module Package = Package
+  module Dialect = Dialect
 end
 
 include Dune_engine.No_io