done with scaffolding for file mailbox; next, send message to file mailbox to export and import, and handle these messages properly from the file mailbox

dotscape.mlb

@@ -46,6 +46,7 @@ end
 imperative-shell/input-callbacks.sml
 
 imperative-shell/update-thread.sml
+imperative-shell/file-thread.sml
 imperative-shell/draw-thread.sml
 
 imperative-shell/shell.sml

imperative-shell/file-thread.sml

@@ -0,0 +1,20 @@
+signature FILE_THREAD =
+sig
+  val run: FileMessage.t Mailbox.mbox -> unit
+end
+
+structure FileThread :> FILE_THREAD =
+struct
+  open FileMessage
+
+  fun run fileMailbox =
+    let
+      val _ =
+        case Mailbox.recv fileMailbox of
+          SAVE_TRIANGLES triangles => ()
+        | EXPORT_TRIANGLES triangles => ()
+        | IMPORT_TRIANGLES => ()
+    in
+      run fileMailbox
+    end
+end

imperative-shell/shell.sml

@@ -28,11 +28,13 @@ struct
 
       val inputMailbox = Mailbox.mailbox ()
       val drawMailbox = Mailbox.mailbox ()
+      val fileMailbox = Mailbox.mailbox ()
+
+      val _ = InputCallbacks.registerCallbacks (window, inputMailbox)
 
       val _ = CML.spawn (fn () =>
-        InputCallbacks.registerCallbacks (window, inputMailbox))
-      val _ = CML.spawn (fn () =>
-        UpdateThread.run (inputMailbox, drawMailbox, initialModel))
+        UpdateThread.run (inputMailbox, drawMailbox, fileMailbox, initialModel))
+
       val _ = CML.spawn (fn () =>
         DrawThread.run
           ( drawMailbox
@@ -44,6 +46,8 @@ struct
           , triangleDrawObject
           , 0
           ))
+
+      val _ = CML.spawn (fn () => FileThread.run fileMailbox)
     in
       ()
     end

imperative-shell/update-thread.sml

@@ -3,6 +3,7 @@ sig
   val run:
       InputMessage.t Mailbox.mbox
     * DrawMessage.t Mailbox.mbox
+    * FileMessage.t Mailbox.mbox
     * AppType.app_type
     -> unit
 end
@@ -12,21 +13,21 @@ struct
   open CML
   open UpdateMessage
 
-  fun handleMsg (drawMailbox, updateMsg) =
+  fun handleMsg (drawMailbox, fileMailbox, updateMsg) =
     case updateMsg of
       DRAW drawMsg => Mailbox.send (drawMailbox, drawMsg)
-    | FILE fileMsg => ()
+    | FILE fileMsg => Mailbox.send (fileMailbox, fileMsg)
     | NO_MAILBOX => ()
 
-  fun loop (inputMailbox, drawMailbox, model) =
+  fun loop (inputMailbox, drawMailbox, fileMailbox, model) =
     let
       val inputMsg = Mailbox.recv inputMailbox
       val (model, updateMsg) = AppUpdate.update (model, inputMsg)
-      val _ = handleMsg (drawMailbox, updateMsg)
+      val _ = handleMsg (drawMailbox, fileMailbox, updateMsg)
     in
-      loop (inputMailbox, drawMailbox, model)
+      loop (inputMailbox, drawMailbox, fileMailbox, model)
     end
 
-  fun run (inputMailbox, drawMailbox, initial) =
-    loop (inputMailbox, drawMailbox, initial)
+  fun run (inputMailbox, drawMailbox, fileMailbox, initial) =
+    loop (inputMailbox, drawMailbox, fileMailbox, initial)
 end

message-types/file-msg.sml

@@ -2,14 +2,14 @@ signature FILE_MESSAGE =
 sig
   datatype t =
     SAVE_TRIANGLES of AppType.triangle list
-  | EXPORT_FILE of AppType.triangle list
-  | IMPORT_FILE
+  | EXPORT_TRIANGLES of AppType.triangle list
+  | IMPORT_TRIANGLES
 end
 
 structure FileMessage :> FILE_MESSAGE =
 struct
   datatype t =
     SAVE_TRIANGLES of AppType.triangle list
-  | EXPORT_FILE of AppType.triangle list
-  | IMPORT_FILE
+  | EXPORT_TRIANGLES of AppType.triangle list
+  | IMPORT_TRIANGLES
 end