This is completely putting the cart before the horse. And going down
that road creates a circular line of reasoning which has no end to the
loop cycle. Plus it is a radical change in fundamental behavior.
Please don't.
I disagree with the above, obviously. See below.
The entire reason that bash's readline emacs mode uses C-n and C-p is
that those are the emacs keys for next-line and previous-line. If
emacs were using M-p and M-n for previous and next then bash would
have done so too. Bash didn't make this up. It is using the keys
from emacs for emacs mode and those keys are C-n and C-p. Editing the
history is just like editing a file. C-p takes you to the previous
line. C-n takes you to the next line.
Then, that model used in bash is precisely what I think should be
changed (generalized), to match the emacs one: Emacs' minibuffer
distinguishes between (a) different lines within the current command
and (b) different commands. And that distinction is good, because it
allows for a richer user interface: you can, on one hand, move across
different commands (with M-p/M-n), and OTOH, move across different
lines in the current selected command (with C-p/C-n). It is simply a
richer (better) model, IMHO.
Now enter emacs. I mean literally. (I have been using emacs for a
very long time by the way. I am using it now.) Emacs has the feature
including of being able to edit the minibuffer and also being able to
run an inferior shell process in a buffer. Both are very similar
cases and should be discussed together.
I definitely think they are different scenarios. But see below.
In those buffers if you want
to go to the previous line or the next line then what keys do you use?
You use C-p and C-n to go to the previous line or the next line.
Of course: you are in a buffer in Emacs, and the standard commands to
move across lines within a buffer are those (C-p/C-n).
But that is not editing the history. That is editing the buffer.
Indeed.
There the previous and next lines are parts of the visible screen. It
isn't a history of the screen. For using bash in an inferior shell if
you want to recall shell history you can't use C-p and C-n because
those are shadowed by the emacs layer of keybindings that move
previous and next lines. Therefore M-p and M-n were the natural
second choice to navigate by adding another mental layer of
navigation. (Although emacs itself is keeping the input history.)
Same thing for the minibuffer.
That is another example of the inconsistency I'd like to remove: In
Emacs, the standard commands for moving across histories (commands,
files, buffers, bookmarks, etc) are M-p and M-n. And for that reason,
you have to use those keys for browsing the command history of the
inferior shell (and C-p/C-n are, as always, employed for moving across
lines in the current buffer).
So now people say, I am now used to using M-p and M-n in emacs to
avoid the C-p/C-n. Let's set that up for bash. (Of course you can
easily do this if you desire. Just do it. Several people suggested
it.)
Yes, I can do it in my .bashrc, but the point is to remove this
inconsistency upstream.
Well, let's say for discussion that you get used to that
setting. The entire argument so far is that people are used to it.
No. See above. The entire argument is that Emacs uses a more general
and richer model, and it would be nice if Bash could adopt that same
model.
Now people become used to navigating the previous line with M-p and
the next line with M-n in bash. Now they go to emacs. What do they
do there? They find that in emacs M-p and M-n *do not navigate* the
previous line and next line. They find that bash and emacs are once
again inconsistent!
Not at all. They find that in Emacs, M-p and M-n, as always, are for
navigating across consecutive entries (whether multiline or
single-line) in every history of elements (including commands). And
that would be perfectly consistent with Bash (if it used M-p/M-n for
the same purpose, instead of C-p/C-n).
In that future time let me file a bug with emacs asking for them to
change their previous-line and next-line key bindings to be compatible
with the new bash bindings of M-p and M-n for previous and next line.
Why? Because they are used to it. That request is just as valid as
this request to do so with bash.
Not at all. See above. Againg: Emacs would not have to change
anything to be consistent with Bash:
* M-p/M-n for browsing the history.
* C-p/C-n for moving across lines within a single entry/buffer.
I think/hope that my point is clear enough already.
--
Dani Moncayo
