Re: BIKESHED: completion faces

[Juri Linkov <juri@linkov.net>]

> Speaking of other editors, the usual way to pick a completion there is
> either to use arrow keys then press RET, or to press TAB several times.

Speaking of using arrow keys and RET, this reminded how completion
works in web browsers.  In both Firefox and Chromium completions
are highlighted in bold, but Chromium doesn't hesitate to use
different highlighting for different completion styles in the
same completions list.  The first part of so called omnibox
displays completions from history/bookmarks using flex completion
style where matched characters are highlighted in bold.  The bottom
part of the same omnibox displays search results using prefix completion
style where bold is used for non-matched parts (i.e. the inverse of
Emacs completions-common-part, i.e. substrings starting from
completions-first-difference are highlighted in bold).

This screenshot demonstrates different completion styles:
https://www.chromestory.com/2018/05/omnibox-redesign/
where "time" in the link from bookmark/history
is highlighted in bold for flex completion style,
but "time" in search results for prefix completion style
is not highlighted.  Instead it highlights the remaining part
to help the user to continue typing the highlighted characters.