refactor string->sexp happens in S2

src/n2/dune

@@ -5,4 +5,4 @@
    adam
    s2
    ohlog
-   sexplib))
+   sexplib0))

src/n2/n2.ml

@@ -1,5 +1,4 @@
 open Adam
-module Sexp = Sexplib0.Sexp
 
 include (val Ohlog.logs "N2")
 
@@ -144,6 +143,9 @@ end
 *)
 
 module Scene = struct
+  module Sexp = Sexplib0.Sexp
+  open Sexplib0.Sexp_conv
+
   include (val Ohlog.sublogs logger "Scene")
 
   type t = {
@@ -156,36 +158,42 @@ module Scene = struct
     sprites : Sprite_graph.node list;
   }
 
+  let get t name = try Hashtbl.find t.objs name
+    with Not_found ->
+      Format.ksprintf failwith "no node %S in scene" name
+
+  let transform obj = obj.transform
+
   let parse_transform_arg ~(tf : mat2a) = function
     | Sexp.List [Atom "tx"; arg] ->
-      tf.a2 <- Sexplib.Conv.float_of_sexp arg
+      tf.a2 <- float_of_sexp arg
     | Sexp.List [Atom "ty"; arg] ->
-      tf.a5 <- Sexplib.Conv.float_of_sexp arg
+      tf.a5 <- float_of_sexp arg
     | Sexp.List [Atom "sx"; arg] ->
-      tf.a0 <- Sexplib.Conv.float_of_sexp arg
+      tf.a0 <- float_of_sexp arg
     | Sexp.List [Atom "sy"; arg] ->
-      tf.a4 <- Sexplib.Conv.float_of_sexp arg
+      tf.a4 <- float_of_sexp arg
     | sexp ->
-      Sexplib.Conv.of_sexp_error "bad argument to transform" sexp
+      of_sexp_error "bad argument to transform" sexp
 
   let parse_sprite_arg ~(rect : aabb) ~(fill : color) = function
     | Sexp.List [Atom "rect"; x0; x1; y0; y1] ->
       AABB.set rect
-        ~x0:(Sexplib.Conv.float_of_sexp x0)
-        ~y0:(Sexplib.Conv.float_of_sexp x1)
-        ~x1:(Sexplib.Conv.float_of_sexp y0)
-        ~y1:(Sexplib.Conv.float_of_sexp y1)
+        ~x0:(float_of_sexp x0)
+        ~y0:(float_of_sexp x1)
+        ~x1:(float_of_sexp y0)
+        ~y1:(float_of_sexp y1)
     | Sexp.List [Atom "fill"; rgb] ->
       Color.set_rgb24 fill
         (Sexplib.Conv.int_of_sexp rgb)
     | Sexp.List [Atom "fill"; r; g; b] ->
       begin
-        fill.r <- Sexplib.Conv.float_of_sexp r;
-        fill.g <- Sexplib.Conv.float_of_sexp g;
-        fill.b <- Sexplib.Conv.float_of_sexp b;
+        fill.r <- float_of_sexp r;
+        fill.g <- float_of_sexp g;
+        fill.b <- float_of_sexp b;
       end
     | sexp ->
-      Sexplib.Conv.of_sexp_error "bad argument to sprite" sexp
+      of_sexp_error "bad argument to sprite" sexp
 
   let parse_sprite ~sg ~tf = function
     | Sexp.List (Atom "sprite" :: args) ->
@@ -194,7 +202,7 @@ module Scene = struct
       List.iter (parse_sprite_arg ~rect ~fill) args;
       Sprite_graph.add_rect sg ~tf ~bb:rect ~fill
     | sexp ->
-      Sexplib.Conv.of_sexp_error "invalid sprite" sexp
+      of_sexp_error "invalid sprite" sexp
 
   let rec parse_obj t ~tg ~sg ~parent = function
     | Sexp.List (Atom "object" :: args) ->
@@ -208,7 +216,7 @@ module Scene = struct
         obj.name;
       obj
     | sexp ->
-      Sexplib.Conv.of_sexp_error "invalid object" sexp
+      of_sexp_error "invalid object" sexp
 
   and parse_obj_args t obj ~tg ~sg = function
     | [] -> { obj with sprites = List.rev obj.sprites }
@@ -237,7 +245,7 @@ module Scene = struct
         trace (fun m -> m "parse_obj_args: end object");
         parse_obj_args t obj args ~tg ~sg
       | sexp ->
-        Sexplib.Conv.of_sexp_error "bad argument to object" sexp
+        of_sexp_error "bad argument to object" sexp
 
   let of_sexp ~tg ~sg = function
     | Sexp.List [Atom "scene"; root] ->
@@ -248,27 +256,10 @@ module Scene = struct
       t
 
     | sexp ->
-      Sexplib.Conv.of_sexp_error "invalid scene" sexp
+      of_sexp_error "invalid scene" sexp
 
   let load name ~tg ~sg =
-    let path = Format.sprintf "%s.scene" name in
-    match Sexplib.Sexp.of_string_conv
-            (S2.Asset.load_file path)
-            (of_sexp ~tg ~sg)
-    with
-    | `Result v ->
-      debug (fun m -> m "loaded scene %S" name);
-      v
-    | `Error (exn, _) ->
-      let msg = match exn with
-        | Failure msg -> msg
-        | exn -> Printexc.to_string exn
-      in
-      raise (S2.Asset.Error (path, "parse error: " ^ msg))
-
-  let get t name =
-    try Hashtbl.find t.objs name
-    with Not_found -> Format.ksprintf failwith "no node %S in scene" name
-
-  let transform obj = obj.transform
+    S2.Asset.load_sexp_conv
+      (name ^ ".scene")
+      (of_sexp ~tg ~sg)
 end

src/n2/n2.mli

@@ -1,6 +1,5 @@
 open Adam
 open S2
-module Sexp = Sexplib0.Sexp
 
 module Transform_graph : sig
   type t

src/s2/asset.ml

@@ -23,3 +23,11 @@ let load_file path =
     | n -> read (i + n)
   in
   Bytes.sub_string buf 0 (read 0)
+
+let load_sexp_conv path of_sexp =
+  try
+    load_file path
+    |> Sexplib.Sexp.of_string
+    |> of_sexp
+  with Sexplib.Conv.Of_sexp_error (Failure msg, _) ->
+    raise (Error (path, "parse error: " ^ msg))

src/s2/dune

@@ -6,4 +6,5 @@
 
    ohlog
    tsdl
-   tgls.tgl4))
+   tgls.tgl4
+   sexplib))