`bind` support required by `fzf` and others not available

[kachick]

I'm using junegunn/fzf-git.sh in my rc. So automatically loading it by brush is making errors.

For example https://github.com/junegunn/fzf-git.sh/blob/4efe76b0b582e9883e19af50fb364b95d93baaf5/fzf-git.sh#L292C5-L292C57

> ./result/bin/brush --version
brush 0.2.14 (cargo:0.2.14)

> ./result/bin/brush --noprofile
UNIMPLEMENTED: pwd with -P or -L
error: unexpected argument '"\er": redraw-current-line' found

Usage: bind [OPTIONS]

For more information, try '--help'.

error: unexpected argument '"\C-g\C-f": "`_fzf_git_files`\e\C-e\er"' found

Usage: bind [OPTIONS]

For more information, try '--help'.

error: unexpected argument '"\C-gf": "`_fzf_git_files`\e\C-e\er"' found
...

It does not appear when I run with --norc

> ./result/bin/brush --norc
brush$

[reubeno]

Thanks for reporting this! I wasn't familiar with fzf-git.sh; I'll need to check it out.

I see multiple issues here:

• Something is invoking pwd with -L or -P; these are known to be unimplemented. There's a pending PR (feat: implement physical and logical cwd #219) that should address this--and I'll be working to shepherd in that change in the next few weeks. I don't think this is coming from fzf-git.sh as it didn't reproduce for me, but could be coming from something else in .bashrc et al. We'll use that pending PR to track progress on this item.

• bind is being passed a positional argument with a key binding; the current stub implementation of bind in brush inadvertently missed that. Instead of it being a syntax error, it should be getting parsed correctly and reported as unimplemented. I've just posted a quick PR ( fix(builtins): correct parsing of bind positional arg #381 ) to address this.

• The Big One: bind isn't really implemented in brush. We don't use readline, so we can't directly pass along the binding configuration. There's a rich set of options in the reedline crate we use to configure custom key bindings, although we haven't fully investigated to confirm that we can support all of bind. From a quick look, the one other big issue we might need to sort out is how to change key bindings in reedline after we've started the shell. It seems like it should be doable, but might need more investigation to confirm as well. We'll use this issue to track this.

---

So... with some targeted changes, I think we could clean up the errors. Beyond that, with time and some feature work, it seems feasible that we could make things actually work--but it will take a fair bit of effort (won't be a quick fix). If someone is specifically passionate about this scenario, I'd welcome some help and collaboration :).

[reubeno]

For what it's worth, I've done some experimentation with wiring up a way for the bind built-in to be able to request service from the InteractiveShell implementation (primaril, reedline). The trickiest bits so far were in getting the right kinds of shareable reedline helper objects that we could also access via "upcalls" from brush builtins.

Getting the full bind functionality required for a script like fzf-git.sh might be a challenge and expose limitations in the kinds of bindings that reedline supports out of the box, but I didn't quite get far enough to make a fair judgment on that.

If someone is interested in picking this up, they're welcome to start with the branch I link above.

[jeremiah]

I've had a similar experience with fzf in a Debian Trixie based container;

jeremiah@TrixieFirst:~$ brush
bind: key seq not implemented: "\er": redraw-current-line
bind: key seq not implemented: "\C-z": emacs-editing-mode
bind: key seq not implemented: "\C-z": emacs-editing-mode
bind: key seq not implemented: "\C-z": vi-editing-mode
ERROR error: UNIMPLEMENTED: bind -x is not yet implemented
ERROR error: UNIMPLEMENTED: bind -x is not yet implemented
ERROR error: UNIMPLEMENTED: bind -x is not yet implemented
ERROR error: UNIMPLEMENTED: bind -x is not yet implemented
ERROR error: UNIMPLEMENTED: bind -x is not yet implemented
ERROR error: UNIMPLEMENTED: bind -x is not yet implemented
bind: key seq not implemented: "\ec": " \C-b\C-k \C-u`__fzf_cd__`\e\C-e\er\C-m\C-y\C-h\e \C-y\ey\C-x\C-x\C-d"
bind: key seq not implemented: "\ec": "\C-z\ec\C-z"
bind: key seq not implemented: "\ec": "\C-z\ec\C-z"
declare: __fzf_list_hosts: not found
ERROR error: UNIMPLEMENTED: set unspecified spec
ERROR error: UNIMPLEMENTED: set unspecified spec

[reubeno]

Thanks for reporting this, @jeremiah.

You'll see above some of the context regarding current bind limitations. The "unspecified spec" error is a good additional call-out too; I don't believe we're specifically tracking that right now (and we should).

Would you mind providing details regarding what's in your .bashrc? Is it just something like eval "$(fzf --bash)"?

[jeremiah]

Yes, that's what I have in my .bashrc (along with copious amounts of other cruft).

# Set up fzf key bindings and fuzzy completion
eval "$(fzf --bash)"

[reubeno]

Thanks for the confirmation; I've filed #434 to track the "unspecified spec" error. That will be an easy fix.

[reubeno]

An update on this thread...

The smaller issues mentioned at the top of this thread (e.g., pwd -P/-L) have since been resolved. For the bigger work, #478 is a big step toward custom key bindings. With that draft work, I now see something much more reasonable when running eval "$(fzf --bash)":

Ctrl+R does, in fact, bring up the fzf UI too! The main remaining pieces will be:

• history builtin isn't implemented (see Implement builtin: history #469). It will require work but should hopefully be able to follow the pattern being established in feat(builtins): implement basic bind -x support #478 for brush-core builtins to invoke optional functionality provided by UX layers (via traits).

• fc builtin isn't implemented. It should hopefully be a good fast-follow to history.

• key bindings that invoke macros or readline functions (as opposed to shell commands/functions) are not yet implemented. Getting them to work for some readline functions could be doable, but it depends on which ones and what we're able to ask reedline to do. Macros, in the general case, may be tough.