Support emacs keybindings throughout the terminal

[chriskrycho]

Describe the bug
Regardless of the setting of the "(Left|Right) Option Key is Meta", ⌥ rarely works for me.

To Reproduce
Steps to reproduce the behavior:

1. Enable either or both of the "(Left|Right) Option Key is Meta" options
2. Try to use ⌥-powered commands for navigating, kill, yank, etc.
3. Observe that it doesn't consistently work.

Annoyingly, it works sometimes, but I haven't been able to identify under what conditions it does/n't work.

Expected behavior
Optimally, a Mac terminal editor should support all the features that CoreText supports out of the box. (I understand that that's a lot of work!)

Screenshots

Just to verify I have the setting turned on:

Desktop (please complete the following information):

• OS Version: macOS Version 11.5.1
• iMac (Retina 5K, 27-inch, 2019)

Additional context
Add any other context about the problem here.

[gagata]

Hi @chriskrycho! The recent stable release should contain the updated handling of the meta key. Since I was not able to repro your issue, do you mind giving it another try? I hope it's resolved, but let me know if not - happy to take another look at this

[chriskrycho]

Giving it a look now!

[chriskrycho]

Still broken, alas. Hitting ⌥B, which should be "move back by a word", just inserts ∫; and hitting ⌥←, which should also be "move back by a word", does nothing. Here's an example of the first:

Screen.Recording.2021-08-16.at.07.55.09.mov

[gagata]

ooh I see! thanks a lot for the video, it's super helpful - the fix enabled meta keybindings in emacs, but not in the rest of the terminal. will take a look at this this week then, just bear with me :)

[zachlloyd]

Changed the title to reflect what I think the underlying issue is, namely that we don't support emacs keybindings in our input area right now.

I think if you are in a focused emacs session, option as meta works as intended.

[zheng]

We added a number of emacs bindings to all the editors in our app. We support most "motion" https://www.gnu.org/software/emacs/refcards/pdf/refcard.pdf keybindings now, but not the goto ones. From killing & deleting, we also do support C-y.

We specifically just added these motion keybindings ones in the last release:
meta-f
meta-backspace
meta-b
meta-a
meta-e
meta-shift-{
meta-shift-}
meta-shift-<
meta-shift->

[zheng]

From rnp on discord:
It's very nice to see some emacs bindings, but they're really incomplete - I use ^B, ^F, ^P, ^N (and their various shift- and meta- variants), and none of those work.
^A, ^E, and ^K work as expected, so I find missing the back/fwd/prev/next bindings even more jarring

[matthewmturner]

@elviskahoro thanks for pointing me to this. im a vim user and having similar issue. in my case, im trying to use vim-tmux-navigator to seemless switch between vim and tmux pane (using Meta+h/j/k/l). interestingly the meta mapping works when im in vim, but then once im in a tmux terminal pane it doesnt.