[ESS] [O] Keyboard shortcut - is there a principle behind them?

[Oleh]

Initially the shortcuts were mnemonic, e.g.
C-e: `move-end-of-line'. Obviously the keys ran out pretty quick.
Now only few shortcuts are reserved for user space and plugins,
the most notable of which is the `C-c` prefix.
That's why most custom modes such as org-mode and ESS bind to shortcuts
with `C-c` prefix: there's a convention that Emacs core will not use `C-c`.

A nice way of remembering shortcuts only when you need them is to
call commands by name with `M-x`.
After a while, when you note that you're using one particular command
a lot, you'll want to learn the shortcut for it.

There's one package that might be of good use to you: `smex'.
It uses ido completion for `M-x`. You can install it from MELPA/Marmelade.
It binds automatically to `M-x` when you install, although I recommend:
(global-set-key "\C-t" 'smex)

As an example, say you want to tangle. Here's what you do:
C-t tang
Now you see a bunch of rectangle commands mixed into the bunch.
You can filter them out by noting that tangle commands have `org` in their name.
C-SPC org C-SPC
Now there's only 7 candidates left and you can select the one you want with C-m
either by cycling with C-s or continuing to type part of name.

`smex` logs the commands you use most. For them it usually takes less
than 2-3 characters
from the name to be recognized.
E.g. if you use `org-babel-tangle` a lot, you can usually call it with
C-t bab C-m.

Finally note that no shortcuts are set in stone. You can customize
all of them if you want to do so.
For instance, and probably a lot of people will disagree, it doesn't
make sense for me to have `previous-line' on C-p. So I swap C-p and C-h:
(keyboard-translate ?\C-h ?\C-p)
(keyboard-translate ?\C-p ?\C-h)

Oleh


On Fri, Dec 6, 2013 at 10:02 AM, Rainer M Krug <Rainer at krugs.de> wrote:
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> Hi
>
> one alternative subject could be "because it is Friday"...
>
> I am using org-mode and ess regularly, and I use quite a few keyboard
> shortcuts, but each time I read about a new one, I am wondering: why
> the heck these specific (default!) keyboard shortcuts?
>
> I am not asking why keyboard sequence, but e.g. why "export" in org is
> C-c e and why tangle is C-c C-v t, and so on.
>
> In other words: I am trying to *understand* why C-c and not C-o,
> because I have tremendous problems to remember the shortcuts - if I
> would know that there is s tree structure, where each following key
> narrows it down to further *thematically linked* commands, it would
> make it easier to learn these.
>
> Any insight into this? Or is there a emacs function which returns a
> random keyboard shortcut for a given function (some emacs shortcuts
> really seem to be that way...).
>
> Thanks,
>
> Rainer
>
>
> - --
> Rainer M. Krug, PhD (Conservation Ecology, SUN), MSc (Conservation
> Biology, UCT), Dipl. Phys. (Germany)
>
> Centre of Excellence for Invasion Biology
> Stellenbosch University
> South Africa
>
> Tel :       +33 - (0)9 53 10 27 44
> Cell:       +33 - (0)6 85 62 59 98
> Fax :       +33 - (0)9 58 10 27 44
>
> Fax (D):    +49 - (0)3 21 21 25 22 44
>
> email:      Rainer at krugs.de
>
> Skype:      RMkrug
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