Re: Updating *Completions* as you type

[Juri Linkov]

> Also: it might be nice to switch between history-sorting and
> alphabetized-sorting during the course of completion, both for files and
> buffers.  Maybe we could do that by making a command which puts
> completion into a mode where it just ignores the display-sort-function
> specified by the completion metadata, and just always uses
> completions-sort.

To be able to implement switching between different sort orders
with a new key, first we need to implement revert-buffer-function
(bound to 'g') in the *Completions* buffer.

Then it will be possible just to toggle a new buffer-local variable
(initially set from 'completions-sort') and to revert the *Completions*
buffer with a new sort order.  Also will need to keep a previously
selected candidate that is implemented by your recent patch.