Re: completion autolist has time-sensitive interface

[frederik@ofb.net]

Thanks Bart.

> The delay is almost certainly the time required to generate the 201
> possibilities rather than any "intentional" pause that zsh is doing.

Yeah I wasn't suggesting that, my goodness.

> Yes, at that particular prompt TAB and y/Y are equivalent, also ctrl-C
> and ctrl-D (eof) and n/N are equivalent.
> 
> But there's more going on than that.  Before displaying the prompt,
> zsh checks to see whether you have already typed something else
> (typeahead) and if you have, it assumes you decided to disambiguate
> the input further, so it skips printing the prompt and proceeds as if
> you had answered "n".  So by pressing the second TAB while zsh is
> still working on the set of completion for the menu, you have told the
> shell you don't want to wait for the menu and it should simply
> proceed.
> 
> > 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)
> 
> The faster you press the two TABs, the more likely you are to trigger
> the typeahead detection.
> 
> > 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.
> 
> Back in the day, a lot of people would automatically muscle-memory
> whack the tab key after typing part of a word, realize they didn't
> mean to, and keep typing more of the word.  They were annoyed when the
> shell ate part of their continued typing as the answer to the prompt,
> leaving them with a word with one missing letter in the middle, so the
> shell was changed to not do that.  This is also why pressing a second
> TAB when the prompt does appear is treated as yes.

Interesting! I wonder if some workaround could be devised, either
showing a "..." to indicate that the shell is busy coming up with
completions, or not eating the typeahead when it consists of TABs.

There seems to be a lot of history here, anyway, thanks for explaining
what was going on.

By the way where do we control the number of completions which
triggers the "do you wish to see ..." prompt to appear?

Frederick