From db7ecce6c398a42f14557067bf18b61cf75da80e Mon Sep 17 00:00:00 2001
From: Claudio Sacerdoti Coen <claudio.sacerdoticoen@unibo.it>
Date: Thu, 31 May 2012 13:52:13 +0000
Subject: [PATCH] Thanks to Guarrigue, code for Serializer functor simplified
 using private types. The type system of OCaml is more and more misterious...

---
 .../components/grafite_engine/grafiteTypes.ml |  7 +----
 matita/components/ng_library/nCicLibrary.ml   | 28 ++++++++-----------
 matita/components/ng_library/nCicLibrary.mli  |  2 +-
 3 files changed, 13 insertions(+), 24 deletions(-)

diff --git a/matita/components/grafite_engine/grafiteTypes.ml b/matita/components/grafite_engine/grafiteTypes.ml
index 7cb6bef0c..e3086b2d7 100644
--- a/matita/components/grafite_engine/grafiteTypes.ml
+++ b/matita/components/grafite_engine/grafiteTypes.ml
@@ -51,9 +51,4 @@ class virtual status = fun (b : string) ->
    method set_ng_mode v = {< ng_mode = v >}
  end
 
-module Serializer =
- NCicLibrary.Serializer(struct
-  type dumpable_s = status
-  let get status = (status : #status :> NCicLibrary.dumpable_status)
-  let set (status : dumpable_s) dump_status = status#set_dumpable_status dump_status
- end)
+module Serializer = NCicLibrary.Serializer(struct type dumpable_s = status end)
diff --git a/matita/components/ng_library/nCicLibrary.ml b/matita/components/ng_library/nCicLibrary.ml
index a7129177e..729d62d0e 100644
--- a/matita/components/ng_library/nCicLibrary.ml
+++ b/matita/components/ng_library/nCicLibrary.ml
@@ -215,7 +215,7 @@ module type SerializerType =
   val dependencies_of: baseuri:NUri.uri -> string list
  end
 
-module Serializer(D: sig type dumpable_s val get: dumpable_s -> dumpable_status  val set: dumpable_s -> dumpable_status -> dumpable_s end) =
+module Serializer(D: sig type dumpable_s = private #dumpable_status end) =
  struct
   type dumpable_status = D.dumpable_s
   type 'a register_type =
@@ -247,7 +247,6 @@ module Serializer(D: sig type dumpable_s val get: dumpable_s -> dumpable_status
    end
 
   let serialize ~baseuri status =
-   let status = D.get status in
    let ch = open_out (ng_path_of_baseuri baseuri) in
    Marshal.to_channel ch (magic,(status#dump.dependencies,status#dump.objs)) [];
    close_out ch;
@@ -265,12 +264,10 @@ module Serializer(D: sig type dumpable_s val get: dumpable_s -> dumpable_status
 
   let require2 ~baseuri ~alias_only status =
    try
-    let s = D.get status in
     let status =
-     D.set status
-      (s#set_dump
-        {s#dump with
-        includes = baseuri::List.filter ((<>) baseuri) s#dump.includes}) in
+     status#set_dump
+      {status#dump with
+        includes = baseuri::List.filter ((<>) baseuri) status#dump.includes} in
     let _dependencies,dump = require0 ~baseuri in
      List.fold_right (!require1 ~alias_only) dump status
    with
@@ -283,7 +280,7 @@ module Serializer(D: sig type dumpable_s val get: dumpable_s -> dumpable_status
    let aux (baseuri,fname) ~refresh_uri_in_universe:_ ~refresh_uri_in_term:_
    ~refresh_uri_in_reference:_ ~alias_only status =
      let baseuri = refresh_uri baseuri in
-     if not alias_only && List.mem baseuri (get_transitively_included (D.get status)) then status
+     if not alias_only && List.mem baseuri (get_transitively_included status) then status
      else
       (HLog.warn ("include " ^ (if alias_only then "alias " else "") ^ fname);
       let status = require2 ~baseuri ~alias_only status in
@@ -293,21 +290,18 @@ module Serializer(D: sig type dumpable_s val get: dumpable_s -> dumpable_status
     register#run "include" aux
 
   let require ~baseuri ~fname ~alias_only status =
-   if not alias_only && List.mem baseuri (get_transitively_included (D.get status)) then status
+   if not alias_only && List.mem baseuri (get_transitively_included status) then status
    else
     (let status =
      if not alias_only then
-      let s = D.get status in
-       D.set status
-        (s#set_dump {s#dump with dependencies = fname::s#dump.dependencies})
+      status#set_dump
+       {status#dump with dependencies = fname::status#dump.dependencies}
      else
       status in
     let status = require2 ~baseuri ~alias_only status in
-    let s = D.get status in
-     D.set status
-      (s#set_dump
-        {s#dump with
-          objs = record_include (baseuri,fname)::s#dump.objs }))
+      status#set_dump
+       {status#dump with
+         objs = record_include (baseuri,fname)::status#dump.objs })
 end
 
 let fetch_obj status uri =
diff --git a/matita/components/ng_library/nCicLibrary.mli b/matita/components/ng_library/nCicLibrary.mli
index ee1ed3ece..3d9ab02cb 100644
--- a/matita/components/ng_library/nCicLibrary.mli
+++ b/matita/components/ng_library/nCicLibrary.mli
@@ -77,7 +77,7 @@ module type SerializerType =
   val dependencies_of: baseuri:NUri.uri -> string list
  end
 
-module Serializer(D: sig type dumpable_s val get: dumpable_s -> dumpable_status  val set: dumpable_s -> dumpable_status -> dumpable_s end) :
+module Serializer(D: sig type dumpable_s = private #dumpable_status end) :
   SerializerType with type dumpable_status = D.dumpable_s
 
 val refresh_uri: NUri.uri -> NUri.uri
-- 
2.39.2