have file API operate on state object

drawing_tests.lua

@@ -55,7 +55,7 @@ function test_draw_line()
   edit.update(Editor_state, 0)
   -- The format on disk isn't perfectly stable. Table fields can be reordered.
   -- So just reload from disk to verify.
-  Editor_state.lines = load_from_disk(Editor_state.filename)
+  load_from_disk(Editor_state)
   Text.redraw_all(Editor_state)
   local drawing = Editor_state.lines[1]
   check_eq(#drawing.shapes, 1, 'F - test_draw_line/save/#shapes')
@@ -433,7 +433,7 @@ function test_name_point()
   App.wait_fake_time(3.1)
   edit.update(Editor_state, 0)
   -- change is saved
-  Editor_state.lines = load_from_disk(Editor_state.filename)
+  load_from_disk(Editor_state)
   Text.redraw_all(Editor_state)
   local p2 = Editor_state.lines[1].points[drawing.shapes[1].p2]
   check_eq(p2.name, 'A', 'F - test_name_point/save')
@@ -465,7 +465,7 @@ function test_move_point()
   App.wait_fake_time(3.1)
   edit.update(Editor_state, 0)
   -- line is saved to disk
-  Editor_state.lines = load_from_disk(Editor_state.filename)
+  load_from_disk(Editor_state)
   Text.redraw_all(Editor_state)
   local drawing = Editor_state.lines[1]
   local p2 = Editor_state.lines[1].points[drawing.shapes[1].p2]
@@ -492,7 +492,7 @@ function test_move_point()
   App.wait_fake_time(3.1)
   edit.update(Editor_state, 0)
   -- change is saved
-  Editor_state.lines = load_from_disk(Editor_state.filename)
+  load_from_disk(Editor_state)
   Text.redraw_all(Editor_state)
   local p2 = Editor_state.lines[1].points[drawing.shapes[1].p2]
   check_eq(p2.x, 26, 'F - test_move_point/save/x')
@@ -553,7 +553,7 @@ function test_delete_lines_at_point()
   App.wait_fake_time(3.1)
   edit.update(Editor_state, 0)
   -- deleted points disappear after file is reloaded
-  Editor_state.lines = load_from_disk(Editor_state.filename)
+  load_from_disk(Editor_state)
   Text.redraw_all(Editor_state)
   check_eq(#Editor_state.lines[1].shapes, 0, 'F - test_delete_lines_at_point/save')
 end
@@ -687,7 +687,7 @@ function test_undo_name_point()
   App.wait_fake_time(3.1)
   edit.update(Editor_state, 0)
   -- undo is saved
-  Editor_state.lines = load_from_disk(Editor_state.filename)
+  load_from_disk(Editor_state)
   Text.redraw_all(Editor_state)
   local p2 = Editor_state.lines[1].points[drawing.shapes[1].p2]
   check_eq(p2.name, '', 'F - test_undo_name_point/save')
@@ -738,7 +738,7 @@ function test_undo_move_point()
   App.wait_fake_time(3.1)
   edit.update(Editor_state, 0)
   -- undo is saved
-  Editor_state.lines = load_from_disk(Editor_state.filename)
+  load_from_disk(Editor_state)
   Text.redraw_all(Editor_state)
   local p2 = Editor_state.lines[1].points[drawing.shapes[1].p2]
   check_eq(p2.x, 35, 'F - test_undo_move_point/save/x')
@@ -779,7 +779,7 @@ function test_undo_delete_point()
   App.wait_fake_time(3.1)
   edit.update(Editor_state, 0)
   -- undo is saved
-  Editor_state.lines = load_from_disk(Editor_state.filename)
+  load_from_disk(Editor_state)
   Text.redraw_all(Editor_state)
   check_eq(#Editor_state.lines[1].shapes, 2, 'F - test_undo_delete_point/save')
 end

edit.lua

@@ -188,7 +188,7 @@ end
 function edit.update(State, dt)
   Drawing.update(State, dt)
   if State.next_save and State.next_save < App.getTime() then
-    save_to_disk(State.lines, State.filename)
+    save_to_disk(State)
     State.next_save = nil
   end
 end
@@ -202,7 +202,7 @@ end
 function edit.quit(State)
   -- make sure to save before quitting
   if State.next_save then
-    save_to_disk(State.lines, State.filename)
+    save_to_disk(State)
   end
 end
 

file.lua

@@ -1,9 +1,8 @@
 -- primitives for saving to file and loading from file
-function load_from_disk(filename)
-  local infile = App.open_for_reading(filename)
-  local result = load_from_file(infile)
+function load_from_disk(State)
+  local infile = App.open_for_reading(State.filename)
+  State.lines = load_from_file(infile)
   if infile then infile:close() end
-  return result
 end
 
 function load_from_file(infile)
@@ -26,12 +25,12 @@ function load_from_file(infile)
   return result
 end
 
-function save_to_disk(lines, filename)
-  local outfile = App.open_for_writing(filename)
+function save_to_disk(State)
+  local outfile = App.open_for_writing(State.filename)
   if outfile == nil then
-    error('failed to write to "'..filename..'"')
+    error('failed to write to "'..State.filename..'"')
   end
-  for _,line in ipairs(lines) do
+  for _,line in ipairs(State.lines) do
     if line.mode == 'drawing' then
       store_drawing(outfile, line)
     else

main.lua

@@ -39,13 +39,13 @@ function App.initialize(arg)
 
   if #arg > 0 then
     Editor_state.filename = arg[1]
-    Editor_state.lines = load_from_disk(Editor_state.filename)
+    load_from_disk(Editor_state)
     Text.redraw_all(Editor_state)
     Editor_state.screen_top1 = {line=1, pos=1}
     Editor_state.cursor1 = {line=1, pos=1}
     edit.fixup_cursor(Editor_state)
   else
-    Editor_state.lines = load_from_disk(Editor_state.filename)
+    load_from_disk(Editor_state)
     Text.redraw_all(Editor_state)
     edit.fixup_cursor(Editor_state)
   end
@@ -117,7 +117,7 @@ end
 function App.filedropped(file)
   -- first make sure to save edits on any existing file
   if Editor_state.next_save then
-    save_to_disk(Editor_state.lines, Editor_state.filename)
+    save_to_disk(Editor_state)
   end
   -- clear the slate for the new file
   App.initialize_globals()  -- in particular, forget all undo history