Re: What's your favourite *under_publicized* editing feature ofEmacs?

[Cthun]

On 23/02/2011 12:22 AM, Tim X wrote:
> Cthun<cthun_117@qmail.net.au>  writes:
>
> > On 22/02/2011 2:47 PM, Alan Mackenzie wrote:
> > > There seems to be a contradiction between those last two paragraphs.
> > > Saving buffers and finding files are relatively rare operations which
> > > thus shouldn't be given very easy to press key sequences like C-s and
> > > C-o.
> >
> > Where do you live where software never crashes and the electricity never goes
> > out? Most of us learn to save very frequently to limit how much we'll have to
> > do over again if the power goes out or whatever.
>
> Most of us use smart editors that auto-save regularly and free the user
> form having to do this manually all the time.

Ah, auto-save, another fruitful source of trouble.

Auto-save has two design alternatives. One, it just acts like the user 
hit control-S, every some interval.

This runs into trouble if you do something drastic you later want to 
undo. Sure you can fork the file, but if you forget ... and then there's 
forking it "dangerously" -- first you make a big deletion, and then you 
hit alt, f, a for save-as to save the drastically-changed version under 
a new name, but pow, an autosave happens to occur *after* the deletion 
and *before* the save-as. So much for being able to undo it...

The other option is auto-save to some temporary file, or a sequence of 
numbered files. Of course if you have a power outage or something now 
you have to go hunting for where the darn thing saved these. Depending, 
they may even be vulnerable to being erased by an automatic temp file 
cleanup script before you get to them.

Sequences of numbered files used to risk filling up the filesystem, too, 
but not with text files in this day and age.