Re: vertical fido-mode

[Juri Linkov]

>>An alternative would be to use the same keys as used in web browsers
>>to navigate completions from the url input field where M-up and M-down
>>are used to display a list of completions and to navigate in completions,
>>without switching to the completions buffer.
>>
> yes, but this is what we have already in fido and the others somehow. I
> wanted to keep things easier.

Easier can be only one thing: to use arrows and navigation keys to navigate
completions from the minibuffer.  So the main question is on what condition
to activate these keys (instead of allowing them to search in history)?

Since making TAB more DWIM doesn't work, what about the following solution:
activate completions navigation keys and display the completions buffer
only when there is some input in the minibuffer, i.e. when the minibuffer's
content is different from its default value.

Or similar to this https://api.jqueryui.com/autocomplete/#option-minLength
activate completions only when input is longer than the minimum number
of characters.