add CHAR_EVENT message type (next is to handle hjkl navigation)

fcore/app-update.sml

@@ -19,6 +19,16 @@ struct
       (newApp, drawMsg)
     end
 
-  fun update (app, msg) =
-    case msg of RESIZE_EVENT (width, height) => resizeText (app, width, height)
+  fun handleChr (app, chr) =
+    let
+      val chr = Char.toString chr ^ "\n"
+      val () = print chr
+    in
+      (app, [])
+    end
+
+  fun update (app, msg) =
+    case msg of
+      RESIZE_EVENT (width, height) => resizeText (app, width, height)
+    | CHAR_EVENT chr => handleChr (app, chr)
 end

message-types/input-msg.sml

@@ -2,10 +2,12 @@ signature INPUT_MSG =
 sig
   datatype t = 
     RESIZE_EVENT of int * int 
+  | CHAR_EVENT of char
 end
 
 structure InputMsg :> INPUT_MSG = 
 struct 
   datatype t = 
     RESIZE_EVENT of int * int 
+  | CHAR_EVENT of char
 end

shell/shell.sml

@@ -6,13 +6,12 @@ struct
   fun frameBufferSizeCallback inputMailbox (width, height) =
     Mailbox.send (inputMailbox, RESIZE_EVENT (width, height))
 
-  fun charCallback word =
+  fun charCallback inputMailbox word =
     let
       val word = Word32.toInt word
       val chr = Char.chr word
-      val s = Char.toString chr ^ "\n"
     in
-      print s
+      Mailbox.send (inputMailbox, CHAR_EVENT chr)
     end
 
   fun registerCallbacks (inputMailbox, window) =
@@ -21,6 +20,7 @@ struct
       val () = Input.exportFramebufferSizeCallback resizeCallback
       val () = Input.setFramebufferSizeCallback window
 
+      val charCallback = charCallback inputMailbox
       val () = Input.exportCharCallback charCallback
       val () = Input.setCharCallback window
     in