Re: completion autolist has time-sensitive interface

[frederik@ofb.net]

I'm adding zsh-users at Peter's suggestion.

Thanks in advance.

On Wed, Aug 15, 2018 at 09:33:58AM +0100, Peter Stephenson wrote:
> On Tue, 14 Aug 2018 22:49:58 -0700
> <frederik@ofb.net> wrote:
> 
> > Dear Zsh Hackers,
> > 
> > Sometimes completion is so laggy on my system that when I press TAB
> > after e.g. "man perl", nothing seems to happen. So I press it again.
> > Still nothing happens. Completion seems broken.
> > 
> > Took me a while to figure out the problem. It's related to "setopt
> > autolist" (which is on by default for me?).
> > 
> > What happens is that if I just press TAB once, e.g. after "man perl",
> > there is a one-second delay and a prompt "zsh: do you wish to see all
> > 201 possibilities (51 lines)?". At this point I can press TAB again,
> > which is equivalent to "y" I guess, and I see a list of completions.
> > 
> > However, if I press TAB twice quickly in succession then I see no
> > list, it is exactly as if there are no completions at all. (Actually
> > if the prompt is at the bottom of the screen, I get a newline) I find
> > it confusing that the completion interface would be time-sensitive in
> > this manner. Why TAB-delay-TAB would behave differently from TAB-TAB.
> > Usually everything I do on the terminal has the property that it
> > doesn't matter how fast or slow I type, it's only the order of the
> > keys that's important...
> 
> One possibility would be if you had (presumably inadvertently) a
> key with TAB as a prefix.  Then it would delay to see if you're
> going to type the full key stroke, and only execute the TAB binding
> if you didn't.  It's not very likely, but it's the best I can think
> of.
> 
> If you run
> 
> bindkey | grep '\^I'
> 
> you'll probably see something like
> 
> "^I" complete-word
> "^[^I" self-insert-unmeta
> 
> where the second isn't relevant as there's an ESC in front.  If you
> see something else starting with ^I that's a problem.
> 
> BTW this is probably more suitable for zsh-users where the larger
> audience is more likely to have seen something similar.

Thanks. When I run `bindkey | grep '\^I'` it shows me the same thing
that you see.

Maybe it will be hard for others to reproduce this as a slow computer
is needed. Or maybe if there were some way to run Zsh with input
provided programmatically, like `echo "man perl\t\t" | zsh`...

Frederick