Re: C-x a C-x C-h

[Deniz Dogan <deniz.a.m.dogan@gmail.com>]

2009/8/27 Drew Adams <drew.adams@oracle.com>:
>> >> When I hit `C-x a C-x' in the latest Emacs, it awaits
>> further input,
>> >> as if it was a prefix key sequence. However, `C-x a C-x
>> C-h' reveals
>> >> that there are no commands bound to anything beginning with that
>> >> prefix. Why?
>> >
>> > Good question. I wonder too. Same thing in Emacs 22, 21, and 20.
>> > And C-x C-x C-x C-x C-x ... just keeps on keepin on.
>>
>> That doesn't happen here, it only gets to `C-x a C-x C-x', after which
>> any further keypresses will say the sequence undefined.
>
> I wasn't quite right.
>
> On Emacs 20 and 21, you can just keep repeating C-x forever, with no apparent
> effect.
>
> On Emac 22 and 23, it seems that C-x a C-x C-x C-x calls
> `exchange-point-and-mark', and every other `C-x' after that calls it again. So
> here too I can keep repeating C-x C-x..., but each such pair invokes
> `exchange-point-and-mark'.
>

You're right, I tried it without having set mark. It wasn't undefined here.

-- 
Deniz Dogan