Feature Request: completion for history events

Feature Request: completion for history events

[Hendrik Jaeger]

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Hi

I want to request a feature: completion for history events.

I imagine it to work like this:
typing this:
```
ls !<TAB>
```
should provide similar output to the 'first event' output when typing:
```
fc -<TAB>
```

I sometimes find myself in the situation that I need to reuse some argument from an earlier command (usually a filename) but I have no idea how many commands ago I used that argument.
Having tab-completion for '!' would allow me to see the history and pick the right command (e.g. -3) and following this up with the right argument index (e.g. :4) without having to cancel the command I already typed to look at the history.

I hope this description is clear but I’m happy to clarify any questions.
Also if there is another way of achieving the same goal, I might not be aware of it and would appreciate a pointer.

Thank you very much for considering this, but also for how awesome zsh already is!

henk

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Re: Feature Request: completion for history events

[Bart Schaefer]

On Thu, Dec 29, 2022 at 4:41 AM Hendrik Jaeger
<ml_zsh-workers@henk.geekmail.org> wrote:
>
> I want to request a feature: completion for history events.

The usual ways to do this aren't exactly what you're envisioning.

The first way is, instead of starting out by typing "!", simply type
ESC-/ (the default binding for the _history_complete_word widget).

Another way is to add _history to your completer zstyle so that
history words are included when you type TAB.  Again you would not
start with "!", instead you'd type a few letters of the word you want,
or just hit TAB and find the word in the resulting list.  E.g.:
  zstyle ':completion:*' completer _oldlist _expand _complete _history
_approximate

Both of these are going to help you find the word you want and insert
the word directly, rather than completing a history event designator.
If you actually want to see a list of history events, we can build
something more complicated by stealing a bit of the guts of the _fc
completion function:

# --8< --
_complete_history_event () {
  local -a events expl
  local num cmd
  if [[ $words[CURRENT] = '!'(|-) ]]
  then
    for num cmd in "${(kv@)history}"
    do
      (( num=num - HISTNO ))
      events+=("${(r.1+$#HISTNO.)num} -- $cmd")
    done
    events=(${events/-/!-})
    _wanted -2V events expl "history event" compadd -Q -ld events -
"${events[@]%% *}" &&
      compstate[list]="list force"
  else
    return 1
  fi
}
_mainly_complete_history() {
  _main_complete _complete_history_event || _main_complete
}
zle -C complete-word .complete-word _mainly_complete_history
bindkey '\t' complete-word
# -->8 --

There's probably a better way to do that, the above is a quick hack
devised by looking at the _complete_debug output for "fc -".

Re: Feature Request: completion for history events

[Bart Schaefer]

On Mon, Jan 16, 2023 at 6:34 PM Bart Schaefer <schaefer@brasslantern.com> wrote:
>
>   zstyle ':completion:*' completer _oldlist _expand _complete _history
> _approximate
>
>     _wanted -2V events expl "history event" compadd -Q -ld events -
> "${events[@]%% *}" &&

Please excuse/undo gmail word-wrapping on those two lines.