[BUG] Shift+Up/Down do not work w/ Termion backend about cursive

[gyscos]

Hi, and thanks for the report!

Indeed, it seems the termion backend doesn't currently support shift+arrow (or ctrl+arrow). It doesn't seem to be supported in termion itself.

Termion does return an "unsupported" key code, and we could parse these codes here, but in that case we'd pretty much be doing the backend library's job. I'm not entirely against that, but I slightly prefer the alternatives:

• Properly report these events in termion itself, so we could support it in cursive.
• Use another backend that supports these events, like crossterm.

[hrkfdn]

Thanks, I have switched to Crossterm now, seems to work fine :)