* Vi insert-mode cursor key bindings.
@ 1996-11-26 12:43 Duncan Sinclair
1996-11-26 12:53 ` Zefram
0 siblings, 1 reply; 6+ messages in thread
From: Duncan Sinclair @ 1996-11-26 12:43 UTC (permalink / raw)
To: Zefram; +Cc: zsh-workers
>>I'm curious.... why?
>
>Because vi doesn't bind them, and because <ESC> already has a meaning
>that its use as a prefix would interfere with.
>
>> And what happens if you bind them using bindkey?
>
>It'll work as expected.
>
>>Can we use other ESC-prefixed bindings in vi-insert mode?
>
>Yes, just bind them using bindkey.
These last two statements seem to contradict the first. If an ESC-prefix
will interfere with the command "ESC", then how then does it "work
as expected"? Or if it "works as expected", how does it interfere?
I can see a lot of e-mail to the list saying "the up-arrow key doesn't
work in vi mode". I seem to recall the same happening before.
>Have you tried using this binding after you gave i a count? Look at
>what that binding does; it's a disgusting kludge.
Agreed. But then I'm hardly likely to be using the cursor keys during
count-prefixed inserts with vi. (I don't use the cursor keys during
inserts in vi, in fact, in vi, I don't use the cursor keys at all.)
While I'm just as keen to see a good vi emulation from zle, we must
still realise that zsh is a shell, not an editor. (In vi I don't
use the cursor keys - in zsh I use them all the time.)
There are lots of people out there that think that "up-arrow,return"
is a perfectly reasonable thing to want to do, without having to hit
"esc" first. (myself included.)
If I can bind them manually - without messing up "esc" on it's own -
then I'm content. But I think it'll be a problem for other people.
Cheers,
Duncan.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Vi insert-mode cursor key bindings.
1996-11-26 12:43 Vi insert-mode cursor key bindings Duncan Sinclair
@ 1996-11-26 12:53 ` Zefram
[not found] ` <zefram@dcs.warwick.ac.uk>
0 siblings, 1 reply; 6+ messages in thread
From: Zefram @ 1996-11-26 12:53 UTC (permalink / raw)
To: Duncan Sinclair; +Cc: zefram, zsh-workers
>These last two statements seem to contradict the first. If an ESC-prefix
>will interfere with the command "ESC", then how then does it "work
>as expected"? Or if it "works as expected", how does it interfere?
The cursor keys will then work, but if you press <ESC> there will be a
delay, while zsh waits for the rest of an escape sequence, before
vi-cmd-mode gets executed. I am of the opinion that key-generated
escape sequences are a bad idea in general, for this reason.
>Agreed. But then I'm hardly likely to be using the cursor keys during
>count-prefixed inserts with vi. (I don't use the cursor keys during
>inserts in vi, in fact, in vi, I don't use the cursor keys at all.)
One better: I don't use cursor keys at all. Their behaviour is too
inconsistent to rely on them. (The terminals that I regularly use
don't generate ANSI escape sequences, so they wouldn't work in ZLE.)
>While I'm just as keen to see a good vi emulation from zle, we must
>still realise that zsh is a shell, not an editor. (In vi I don't
>use the cursor keys - in zsh I use them all the time.)
Yes. There is a case to be made for binding the cursor keys, but ...
>If I can bind them manually - without messing up "esc" on it's own -
>then I'm content.
you *can* bind them manually if you want them, so I think we should
default to the better vi emulation.
> But I think it'll be a problem for other people.
Only people that don't read the manual.
-zefram
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Vi insert-mode cursor key bindings.
@ 1996-11-27 18:21 Duncan Sinclair
0 siblings, 0 replies; 6+ messages in thread
From: Duncan Sinclair @ 1996-11-27 18:21 UTC (permalink / raw)
To: Zefram; +Cc: schaefer, zsh-workers
Zefram writes:
>It does the right thing in that case. But <ESC>[A is a likely
>mistyping of some reasonable editing actions. In any case, I find the
>delay annoying: if I pressed <ESC>, it should take the action for <ESC>
>immediately. With no escape sequences around, this is acheivable.
How long is the delay? One second is probably too long. Maybe 200ms
would be OK. I don't know how long a delay nvi uses but it does seem
a little too long. Of course, the delay should be set according to
the value of "BAUD". (Though baud rates are rarely important these days...)
>No. Actually, I usually use a couple of Lear Siegler ADM 3E
>terminals. These generate ^H for left, ^J for down, ^K for up[1] and
>^L for right. Some programs can handle this (vi for one), but many get
>confused.
I occasionally use an ADM 5A, with the same behaviour. Maybe it's
just me, but I always thought this set to be a fairly obvious choice.
>>If we're going to add default bindings for the cursor keys, we should
>>do it right -- we should read the term{cap,info} database and add the
>>binding for what it says the arrow keys generate, not just hardwire to
>>the vt100/ANSI sequences. (Most vi that I've used actually map both
>>the ANSI and terminfo arrow keys, though not in insert mode.)
>
>Yes, we should. But we should watch out for weird terminals like mine,
>and be careful not to squash anything otherwise bound. Personally I
>would miss using right arrow to clear the screen, if it were to be
>rebound.
That's true.
Another thing to watch for is termcap initialisation and the difference
between "<ESC>[A" and "<ESC>OA".
>From the xterm termcap entry:
ku=\EOA:
kd=\EOB:
kr=\EOC:
kl=\EOD:
But the zsh bindings are:
"^[[A" up-line-or-history
"^[[B" down-line-or-history
"^[[C" forward-char
"^[[D" backward-char
These are different because the termcap database is only correct after
the "ti" string has been sent - "ti" is the "string to begin programs
that use termcap". It has a partner - "te".
So, shouldn't we be using "ti"? No. Because on an xterm the "ti"
string does this:
In VT102 mode, there are escape sequences to activate and
deactivate an alternate screen buffer, which is the same
size as the display area of the window. When activated, the
current screen is saved and replaced with the alternate
screen. Saving of lines scrolled off the top of the window
is disabled until the normal screen is restored. The
termcap(5) entry for xterm allows the visual editor vi(1) to
switch to the alternate screen for editing and to restore
the screen on exit.
- xterm man page
I don't think this is what is wanted for an interactive shell.
But then someday you'll find a terminal that won't play unless you
send the "ti" string.
Any thoughts on this? (Apart from lynching Bill Joy for giving us all
this nonsense.)
Cheers,
Duncan.
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~1996-11-27 19:13 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
1996-11-26 12:43 Vi insert-mode cursor key bindings Duncan Sinclair
1996-11-26 12:53 ` Zefram
[not found] ` <zefram@dcs.warwick.ac.uk>
1996-11-26 17:33 ` Bart Schaefer
1996-11-26 18:09 ` Zefram
1996-11-27 0:40 ` Bart Schaefer
1996-11-27 18:21 Duncan Sinclair
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