Re: region_highlight converts `fg=default` to `none`, which is not the same

[Bart Schaefer <schaefer@xxxxxxxxxxxxxxxx>]

On Fri, Oct 16, 2020 at 6:29 AM Daniel Shahaf <d.s@xxxxxxxxxxxxxxxxxx> wrote:
>
> The inconsistent augmentation semantics have bugged me since I first ran
> into them.  I'd love to see them rationalized.

As I recall one of the problems with this is (as Roman mentioned)
there is no way to selectively turn off many of the attributes.  That
is, there's no way to tell the terminal "revert to the previous value
of X", instead we have to keep track of that and explicitly assert
"set X to Y".  In some cases even that's not enough, and the only
right approach is to clear all attributes and then reassert all
attributes.  This shortcoming is directly reflected in the selection
of names/values in Functions/Misc/colors, where I also summarized the
ECMA standard in comments.  (There's probably a newer standard at this
point.)