library: decouple reading file from computing filename

core/single.ml

@@ -20,15 +20,15 @@ let to_m2l policy sig_only (k,f,_n) =
   | None -> None
   | Some k ->
     match Read.file k f with
-    | _name, Ok x ->
+    | Ok x ->
       if sig_only then Some (k, M2l.Sig_only.filter x) else Some (k,x)
-    | _, Error (Ocaml (Syntax msg)) ->
+    | Error (Ocaml (Syntax msg)) ->
       Fault.raise policy Standard_faults.syntaxerr msg;
       Some(k, approx f)
-    | _, Error (Ocaml (Lexer msg)) ->
+    | Error (Ocaml (Lexer msg)) ->
       Fault.raise policy Standard_faults.lexerr (!Location.input_name,msg);
       Some(k, approx f)
-    | _, Error (Serialized e) ->
+    | Error (Serialized e) ->
       Standard_faults.schematic_errors policy (f,"m2l",e); None
 
 let approx_file _ _ ppf _param (_,f,_) =

lib/read.ml

@@ -46,8 +46,6 @@ let source_file kind filename =
   code
 
 let file {format;kind} filename =
-  let name = name filename in
-  name,
   match format with
   | Src | Parsetree -> source_file kind filename
   | M2l ->

lib/read.mli

@@ -19,5 +19,4 @@ type error = Ocaml of ocaml_parsing_error | Serialized of Schematic.Ext.error
 val name: string -> Unitname.t
 (** [name filename] gives the module name corresponding to filename *)
 
-val file: kind -> string ->
-  Unitname.t * (M2l.t, error) result
+val file: kind -> string -> (M2l.t, error) result

tests/step_by_step.ml

@@ -51,20 +51,21 @@ let pp file name deps =
   Format.printf "%a@." pp {dependencies;local; library; unknown}
 
 let () =
-  let file = Sys.argv.(1) in
-  let name, res =
-    Read.file {Read.format=Read.Src; kind=M2l.Structure} file in
+  let filename = Sys.argv.(1) in
+  let modname = Read.name filename in
+  let res =
+    Read.file {Read.format=Read.Src; kind=M2l.Structure} filename in
   let m2l =
     match res with
-    | Error (Ocaml _) -> Format.eprintf "Error when parsing source %a.@." Unitname.pp name; exit 2
-    | Error (Serialized _) -> Format.eprintf "Error when parsing m2l %a.@." Unitname.pp name; exit 2
+    | Error (Ocaml _) -> Format.eprintf "Error when parsing source %a.@." Unitname.pp modname; exit 2
+    | Error (Serialized _) -> Format.eprintf "Error when parsing m2l %a.@." Unitname.pp modname; exit 2
     | Ok x -> x in
   let env =   Envt.start ~open_approximation:true
     ~libs:[]
     ~namespace:[]
     ~implicits:[["Stdlib"], Bundle.stdlib ]
     Module.Dict.empty in
-  let pkg = (Pkg.local file) in
+  let pkg = (Pkg.local filename) in
   let rec loop guard res = match O.next env res ~pkg with
     | Error zipper ->
       if guard = 0 then
@@ -73,4 +74,4 @@ let () =
         loop (guard-1) zipper
     | Ok (_sig, deps) -> deps in
   let deps = loop 1_000_000 (O.initial m2l) in
-  pp file (Modname.to_string (Unitname.modname name)) deps
+  pp filename (Modname.to_string (Unitname.modname modname)) deps