fix lexer/parser bugs, add code in file-thread.sml to handle loading/saving of files (but loading is not completely finished yet)

fcore/parser/parser.sml

@@ -18,18 +18,21 @@ struct
         end
     | _ => SOME (tokens, grid)
 
-  fun parse tokens =
-    case tokens of
-      T.INT canvasWidth :: T.INT canvasHeight :: T.L_BRACE :: tl =>
-        let
-          val grid = ParseGrid.make (canvasWidth, canvasHeight)
-        in
-          case parseItems (tl, grid) of
-            SOME (tokens, grid) =>
-              (case tokens of
-                 [T.R_BRACE] => SOME grid
-               | _ => NONE)
-            | NONE => NONE
-        end
-    | _ => NONE
+  fun parse string =
+    case Lexer.scan string of
+      SOME tokens =>
+        (case tokens of
+           T.INT canvasWidth :: T.INT canvasHeight :: T.L_BRACE :: tl =>
+             let
+               val grid = ParseGrid.make (canvasWidth, canvasHeight)
+             in
+               case parseItems (tl, grid) of
+                 SOME (tokens, grid) =>
+                   (case tokens of
+                      [T.R_BRACE] => SOME (canvasWidth, canvasHeight, grid)
+                    | _ => NONE)
+               | NONE => NONE
+             end
+         | _ => NONE)
+    | NONE => NONE
 end