bug#22785: 24.5; comint/shell modes should be merged with term mode

[Ingo Lohmar <i.lohmar@gmail.com>]

On Tue, Feb 23 2016 12:33 (-0800), Per Bothner wrote:

> The "line" submode of term mode duplicates much of the functionality
> of comint mode.  When I wrote term mode, my hope was that it would
> subsume comint mode, or that comint mode would be built on top of
> term mode.  That never happened - so far.
>
> 'shell mode' should basically be the same as 'term' mode, except
> that shell mode starts of in line-editing mode, while term mode
> starts up in character mode.
>
> There are obvious advantages to merging these modes. One is
> we have ansi escape sequence handling in a single place.
> Another is that you can run console applications from shell mode.



To me, that seems to be a bad idea.  They are two different modes
precisely *because* they are quite different.  If you want to run
console applications, why would you use shell-mode at all?

I dumped any use of term.el because I could not control its
complexities, no matter what overrides, patches and advices I used.  I
have not looked back after using shell-mode where it's useful instead,
and not running console applications anymore.

Term is *significantly* more complex than shell (175k vs 54k), and does
a lot more things (for better or worse).  Maybe factoring out the ANSI
sequence parsing is what you really want?