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

[Jonathan Leech-Pepin]

Hello,

On 6 December 2013 05:01, Rainer M Krug <address@hidden> wrote:
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> On 12/06/13, 10:49 , Oleh wrote:
>> Initially the shortcuts were mnemonic, e.g. C-e:
>> `move-end-of-line'. Obviously the keys ran out pretty quick.
>
> I can really imagine. But this explains some - but following your
> example: C-a moves to the beginning of the line - the only "a" there
> is in "Anfang", which is German for "beginning". So only partial luck
> here.

I can't speak for the original developers however my take on this one
is as follows:

C-b (for beginning) is used for "back"
C-s (for start) is used for "search", C-f (find) was "forward".
C-a becomes beginning-of-line by virtue of being the beginning of the alphabet.

Regards,
Jonathan

>> 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`.
>
> Ah - very good to know.
>
>>
>> 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.
>
> That's how I do it - but it involves learning sequences which do not
> make any sense to me - and I am sure there is some sense in the
> sequence, at least within each mode.
>
>>
>> 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)
>
> Yes - smex and ido are *very* useful - I do not know how one can use
> emacs without them.
>
>>
>> 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.
>
> Very true and very useful.
>
>>
>> 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)
>
> Absolutely true - but I usually try to keep the customization to a
> minimum and to use the defaults.
>
> Thanks,
>
> Rainer
>
>>
>> Oleh
>>
>>
>> On Fri, Dec 6, 2013 at 10:02 AM, Rainer M Krug <address@hidden>
>> wrote: 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
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> email:      address@hidden
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