unikernel/duniverse/dune_/bin/describe/describe_format.ml

@@ -0,0 +1,34 @@
+open Import
+
+type t =
+  | Sexp
+  | Csexp
+
+let all = [ "sexp", Sexp; "csexp", Csexp ]
+
+let arg =
+  let doc = Printf.sprintf "$(docv) must be %s" (Arg.doc_alts_enum all) in
+  Arg.(value & opt (enum all) Sexp & info [ "format" ] ~docv:"FORMAT" ~doc)
+;;
+
+let print_as_sexp dyn =
+  let rec dune_lang_of_sexp : Sexp.t -> Dune_lang.t = function
+    | Atom s -> Dune_lang.atom_or_quoted_string s
+    | List l -> List (List.map l ~f:dune_lang_of_sexp)
+  in
+  let cst =
+    dyn
+    |> Sexp.of_dyn
+    |> dune_lang_of_sexp
+    |> Dune_lang.Ast.add_loc ~loc:Loc.none
+    |> Dune_lang.Cst.concrete
+  in
+  let version = Dune_lang.Syntax.greatest_supported_version_exn Stanza.syntax in
+  Pp.to_fmt Stdlib.Format.std_formatter (Dune_lang.Format.pp_top_sexps ~version [ cst ])
+;;
+
+let print_dyn t dyn =
+  match t with
+  | Csexp -> Csexp.to_channel stdout (Sexp.of_dyn dyn)
+  | Sexp -> print_as_sexp dyn
+;;