RE: Modernize frame-title-format: "%b - GNU Emacs"

[Gregory Heytings]

> But the NONdirectory part of `buffer-file-name' is the most specific 
> part.  And that part is used for the buffer name, which we have with 
> `%b'.  The nondir part should come before (to the left of) the dir part, 
> at least for the default.
>
> If there's ever a need to see some directory info, then it would be 
> better to use a uniquified buffer name than `abbreviate-file-name'. 
> That is, use a `uniquify-buffer-name-style' other than `forward'. And 
> `buffer-name' already gives us this behavior.
>
> To be clear, what's the motivation for adding a `%B' behavior?  (But a 
> priori I have no objection.)
>
> More importantly, what's the motivation for using it for the default 
> behavior?

FWIW, I do not agree that the non-directory part of a file name is the 
most specific part.  This is only partly true.  Where a file is located is 
most often as important as (and sometimes more important than) the file 
name to identify a file, at least of you are a programmer.

In Visual Studio and XCode, the path of the file is displayed just above 
the "buffer".  In Eclipse, it is displayed in the title bar.  And that 
information is displayed in its "natural" order, with the current filename 
on the right.

(Likewise, it is almost standard to display the current working directory 
in full in shell prompts.)

It seems to me that using `(abbreviate-file-name buffer-file-name)' or 
`buffer-file-truename' in Emacs's title bar makes perfect sense.

(An additional option that would also make sense (I think) is to have an 
option so that `abbreviate-file-name' keeps only the initial N letters of 
the directories, for example: "/u/i/stdio.h" or "~/gn/em/sr/dired.c", 
which is shorter, and often clear enough.)