kilo commentary: Page Up and Page Down buttons

Oh, dear. Way back when I started this commentary, I said I didn't want to be critical, but how the Page Up and Page Down buttons are implemented is pretty ugly:

    case PAGE_UP:
    case PAGE_DOWN:
      {
        int times = E.screenrows;
        while (times--)
          editorMoveCursor(c == PAGE_UP ? ARROW_UP : ARROW_DOWN);
      }
      break;

Particularly when the Home and End keys are implemented more like I would expect:

    case HOME_KEY:
      E.cx = 0;
      break;
    case END_KEY:
      E.cx = E.screencols - 1;
      break;

My code:

    case PAGE_UP: 
        editor_set_cursor_row(0);
        break;
 
    case PAGE_DOWN:
        editor_set_cursor_row(g_editor_state.screenrows-1);
        break;

The code for editorReadKey (the final version, at least for this chapter, is here) has also become pretty ugly. Even in this relatively short implementation, all these nested ifs and elses make it very hard to see how the control logic works.

That said, I don't want to take time right now to work out a cleaner solution than the one I have right now (I'm more interested in the other parts of this code) so I'm going to leave this the way I have it. Probably the best answer is to break down and use a third-party library that has already solved this problem.