Make the Ppx_tyxml api a bit friendlier.

Author: Drup

ppx/ppx_tyxml.ml

@@ -173,15 +173,9 @@ let replace_attribute ~loc (attr,value) =
 
     Each token is equipped with a starting (but no ending) position.
 *)
-let ast_to_stream expr =
+let ast_to_stream expressions =
   let current_adjust_location = ref (Loc.adjust Lexing.dummy_pos 0) in
 
-  let expressions =
-    match expr.pexp_desc with
-    | Pexp_apply (f, arguments) -> f::(List.map snd arguments)
-    | _ -> [expr]
-  in
-
   let strings =
     expressions |> List.map @@ fun expr ->
     match expr.pexp_desc with
@@ -321,14 +315,21 @@ let dispatch_ext {txt ; loc} =
     Some (Ppx_common.Svg, get_modname ~loc len l)
   | _ -> None
 
+let application_to_list expr =
+  match expr.pexp_desc with
+  | Pexp_apply (f, arguments) -> f::(List.map snd arguments)
+  | _ -> [expr]
+
+
 open Ast_mapper
 
 let map_expr mapper e =
   match e.pexp_desc with
   | Pexp_extension (ext, payload) ->
     begin match dispatch_ext ext, payload with
     | Some (lang, modname), PStr [{pstr_desc = Pstr_eval (e, _)}] ->
-      markup_to_expr_with_implementation lang modname e.pexp_loc e
+      markup_to_expr_with_implementation lang modname e.pexp_loc @@
+      application_to_list e
     | Some _, _ ->
       Ppx_common.error e.pexp_loc
         "Error: Payload of [%%tyxml] must be a single string"

ppx/ppx_tyxml.mli

@@ -26,7 +26,7 @@
 
 val markup_to_expr :
   Ppx_common.lang ->
-  Location.t -> Parsetree.expression -> Parsetree.expression
+  Location.t -> Parsetree.expression list -> Parsetree.expression
 (** Given the payload of a [%html ...] or [%svg ...] expression,
     converts it to a TyXML expression representing the markup
     contained therein. *)