explicitly state when operations manage undo

edit.lua

@@ -361,7 +361,7 @@ function edit.keychord_press(editor, chord, key)
       -- (we're not creating any ctrl-shift- or alt-shift- combinations using regular/printable keys)
       (not shift_down() or utf8.len(key) == 1) and
       chord ~= 'C-a' and chord ~= 'C-c' and chord ~= 'C-x' and chord ~= 'backspace' and chord ~= 'delete' and chord ~= 'C-z' and chord ~= 'C-y' and not is_cursor_movement(key) then
-    Text.delete_selection(editor, editor.left, editor.right)
+    Text.delete_selection_and_record_undo_event(editor)
   end
   if editor.search_term then
     if chord == 'escape' then
@@ -432,7 +432,7 @@ function edit.keychord_press(editor, chord, key)
       love.system.setClipboardText(s)
     end
   elseif chord == 'C-x' and cursor_on_screen then
-    local s = Text.cut_selection(editor, editor.left, editor.right)
+    local s = Text.cut_selection_and_record_undo_event(editor)
     if s then
       love.system.setClipboardText(s)
     end

select.lua

@@ -5,14 +5,14 @@ function edit.mouse_loc(editor)
   return edit.to_loc(editor, mx, my)
 end
 
-function Text.cut_selection(editor)
+function Text.cut_selection_and_record_undo_event(editor)
   if editor.selection1.line == nil then return end
   local result = Text.selection(editor)
-  Text.delete_selection(editor)
+  Text.delete_selection_and_record_undo_event(editor)
   return result
 end
 
-function Text.delete_selection(editor)
+function Text.delete_selection_and_record_undo_event(editor)
   if editor.selection1.line == nil then return end
   local minl,maxl = minmax(editor.selection1.line, editor.cursor.line)
   local before = snapshot(editor, minl, maxl)

text.lua

@@ -54,7 +54,7 @@ function Text.keychord_press(editor, chord)
   elseif chord == 'backspace' then
     if editor.cursor.mode == 'text' then
       if editor.selection1.line then
-        Text.delete_selection(editor, editor.left, editor.right)
+        Text.delete_selection_and_record_undo_event(editor)
         schedule_save(editor)
         return
       end
@@ -114,7 +114,7 @@ function Text.keychord_press(editor, chord)
     else
       -- cursor in text line
       if editor.selection1.line then
-        Text.delete_selection(editor, editor.left, editor.right)
+        Text.delete_selection_and_record_undo_event(editor)
         schedule_save(editor)
         return
       end