Dune2 formatting (#2347)

Dune2 formatting

CHANGES.md

@@ -76,6 +76,9 @@
 - Change the automatically generated odoc index to only list public modules.
   This only affects unwrapped libraries (#2479, @rgrinberg)
 
+- Set up formatting rules by default. They can be configured through a new
+  `(formatting)` stanza in `dune-project` (#2347, fixes #2315, @emillon)
+
 1.11.0 (23/07/2019)
 -------------------
 

doc/formatting.rst

@@ -15,14 +15,16 @@ Furthermore it can be used to format code of any defined dialect (see
 .. _ocamlformat: https://github.com/ocaml-ppx/ocamlformat
 .. _refmt: https://github.com/facebook/reason/tree/master/src/refmt
 
-Enabling automatic formatting
-=============================
+Configuring automatic formatting (dune 2.0)
+===========================================
 
-This feature is enabled by adding the following to the ``dune-project`` file:
+If using ``(lang dune 2.0)``, there is nothing to do, formatting will be set up
+by default. It is possible to disable it by adding the following to
+``dune-project``:
 
 .. code:: scheme
 
-    (using fmt 1.2)
+    (formatting disabled)
 
 Formatting a project
 ====================
@@ -64,24 +66,47 @@ avoid pulling ``ocamlformat`` as a dependency.
 In these cases, it is possible to use the ``enabled_for`` argument to restrict
 the languages that are considered for formatting.
 
+.. code:: scheme
+
+    (formatting (enabled_for reason))
+
+Enabling and configuring automatic formatting (dune 1.x)
+========================================================
+
+.. note:: This section applies only to projects with ``(lang dune 1.x)``.
+
+In ``(lang dune 1.x)``, no formatting is done by default. This feature is
+enabled by adding the following to the ``dune-project`` file:
+
+.. code:: scheme
+
+    (using fmt 1.2)
+
+Languages can be configured using the following syntax:
+
 .. code:: scheme
 
     (using fmt 1.2 (enabled_for reason))
 
 Version history
 ===============
 
-1.2
----
+(lang dune 2.0)
+---------------
+
+* Formatting is enabled by default.
+
+(using fmt 1.2)
+---------------
 
 * Format :ref:`dialects-main`.
 
-1.1
----
+(using fmt 1.1)
+---------------
 
 * Format Dune files.
 
-1.0
----
+(using fmt 1.0)
+---------------
 
 * Format OCaml (using ocamlformat_) and Reason (using refmt_) source code.

src/dune_file.ml

@@ -623,82 +623,6 @@ end
 
 let modules_field name = Ordered_set_lang.field name
 
-module Auto_format = struct
-  let syntax =
-    Syntax.create ~name:"fmt"
-      ~desc:"integration with automatic formatters"
-      [ (1, 2) ]
-
-  type language =
-    | Dialect of string
-    | Dune
-
-  let language_to_dyn =
-    let open Dyn.Encoder in
-    function
-    | Dialect name -> constr "dialect" [string name]
-    | Dune -> constr "dune" []
-
-  let language = function
-    | "dune" -> Dune
-    | s -> Dialect s
-
-  type enabled_for =
-    | Default of Syntax.Version.t
-    | Only of language list
-
-  let enabled_for_field =
-    let+ r = field_o "enabled_for" (repeat (map ~f:language string))
-    and+ version = Syntax.get_exn syntax
-    in
-    match r with
-    | Some l -> Only l
-    | None -> Default version
-
-  let enabled_for_to_dyn =
-    let open Dyn.Encoder in
-    function
-    | Default v -> constr "default" [Syntax.Version.to_dyn v]
-    | Only l -> constr "only" (List.map ~f:language_to_dyn l)
-
-  type t =
-    { loc : Loc.t
-    ; enabled_for : enabled_for
-    }
-
-  let to_dyn {enabled_for; loc = _} =
-    let open Dyn.Encoder in
-    record ["enabled_for", enabled_for_to_dyn enabled_for]
-
-  let dparse_args =
-    let+ loc = loc
-    and+ enabled_for = fields enabled_for_field
-    in
-    ({loc; enabled_for}, [])
-
-  let key =
-    Dune_project.Extension.register syntax dparse_args to_dyn
-
-  let includes config =
-    match config.enabled_for with
-    | Default ver ->
-      let in_1_0 =
-        [Dialect "ocaml"; Dialect "reason"]
-      in
-      begin match Syntax.Version.compare ver (1, 1) with
-      | Lt ->
-        fun language -> List.mem language ~set:in_1_0
-      | Eq ->
-        fun language -> List.mem language ~set:(Dune :: in_1_0)
-      | Gt ->
-        fun _ -> true
-      end
-    | Only l ->
-      fun language -> List.mem language ~set:l
-
-  let loc t = t.loc
-end
-
 module Buildable = struct
   type t =
     { loc                      : Loc.t

src/dune_file.mli

@@ -125,20 +125,6 @@ module Dep_conf : sig
   val to_dyn : t Dyn.Encoder.t
 end
 
-module Auto_format : sig
-  type language =
-    | Dialect of string
-    | Dune
-
-  type t
-
-  val key : t Dune_project.Extension.t
-
-  val loc : t -> Loc.t
-
-  val includes : t -> language -> bool
-end
-
 module Buildable : sig
   type t =
     { loc                      : Loc.t

src/dune_project.ml

@@ -211,6 +211,7 @@ type t =
   ; file_key : File_key.t
   ; dialects        : Dialect.DB.t
   ; explicit_js_mode : bool
+  ; format_config : Format_config.t option
   }
 
 let equal = (==)
@@ -243,7 +244,7 @@ let to_dyn
       ; extension_args = _; stanza_parser = _ ; packages
       ; implicit_transitive_deps ; wrapped_executables ; dune_version
       ; allow_approx_merlin ; generate_opam_files
-      ; file_key ; dialects ; explicit_js_mode } =
+      ; file_key ; dialects ; explicit_js_mode ; format_config } =
   let open Dyn.Encoder in
   record
     [ "name", Name.to_dyn name
@@ -269,6 +270,7 @@ let to_dyn
     ; "file_key", string file_key
     ; "dialects", Dialect.DB.to_dyn dialects
     ; "explicit_js_mode", bool explicit_js_mode
+    ; "format_config", (option Format_config.to_dyn) format_config
     ]
 
 let find_extension_args t key =
@@ -537,6 +539,17 @@ let wrapped_executables_default ~(lang : Lang.Instance.t) =
 let explicit_js_mode_default ~(lang : Lang.Instance.t) =
   lang.version >= (2, 0)
 
+let format_extension_key =
+  Extension.register
+    Format_config.syntax
+    Format_config.dparse_args
+    Format_config.to_dyn
+
+let format_config t =
+  let ext = find_extension_args t format_extension_key in
+  let dune_lang = t.format_config in
+  Format_config.of_config ~ext ~dune_lang
+
 let anonymous = lazy (
   let lang = get_dune_lang () in
   let name = Name.anonymous_root in
@@ -578,6 +591,7 @@ let anonymous = lazy (
   ; file_key
   ; dialects = Dialect.DB.builtin
   ; explicit_js_mode
+  ; format_config = None
   })
 
 let default_name ~dir ~packages =
@@ -648,6 +662,7 @@ let parse ~dir ~lang ~opam_packages ~file =
          (Syntax.since Stanza.syntax (1, 11) >>> located Dialect.decode)
      and+ explicit_js_mode =
        field_o_b "explicit_js_mode" ~check:(Syntax.since Stanza.syntax (1, 11))
+     and+ format_config = Format_config.field
      in
      let homepage =
        match homepage, source with
@@ -767,6 +782,7 @@ let parse ~dir ~lang ~opam_packages ~file =
      ; generate_opam_files
      ; dialects
      ; explicit_js_mode
+     ; format_config
      })
 
 let load_dune_project ~dir opam_packages =
@@ -816,6 +832,7 @@ let make_jbuilder_project ~dir opam_packages =
   ; wrapped_executables = false
   ; dialects
   ; explicit_js_mode = false
+  ; format_config = None
   }
 
 let load ~dir ~files =

src/dune_project.mli

@@ -84,6 +84,7 @@ val allow_approx_merlin : t -> bool
 val generate_opam_files : t -> bool
 val dialects : t -> Dialect.DB.t
 val explicit_js_mode : t -> bool
+val format_config : t -> Format_config.t option
 
 val equal : t -> t -> bool
 val hash : t -> int