add a function "save" for graphs

.gitignore

+LOCAL/
 build/
 dist/
 _build
@@ -6,3 +7,4 @@ grewpy.native
 bin
 MANIFEST
 *.pyc
+UD_French-GSD

grew/graph.py

@@ -64,6 +64,10 @@ def graph(data=None):
         raise GrewError('Library call error')
 
 
+def save(gr, filename):
+    req = { "command": "save_graph", "graph": json.dumps(gr), "filename": filename }
+    reply = network.send_and_receive(req)
+    return
 
 def add_node(g, s, a):
     """

setup.py

@@ -11,7 +11,7 @@ setuptools.setup(
     description="A binding to the Grew software",
     long_description=long_description,
     long_description_content_type="text/markdown",
-    url="http://grew.fr",
+    url="https://grew.fr",
     author="bguil",
     author_email="Bruno.Guillaume@loria.fr"
 )

src_ocaml/grewpy.ml

@@ -43,6 +43,20 @@ let run_command request =
         | None -> json_error "no 'filename' in 'load_grs' command"
       end
 
+    (* ======================= save_graph ======================= *)
+    | Some "save_graph" ->
+      begin
+        match (
+          json |> member "graph" |> to_string_option,
+          json |> member "filename" |> to_string_option
+        ) with
+        | Some graph, Some filename ->
+          let gr = Graph.of_json_python ~config (Yojson.Basic.from_string graph) in
+            Yojson.Basic.to_file filename (Graph.to_json gr);
+            Yojson.Basic.to_string (`Assoc [("status", `String "OK"); ("data", `Null)])
+        | _ -> json_error "incomplete 'save_graph' command"
+      end
+
     (* ======================= load_grs ======================= *)
     | Some "load_grs" ->
       begin