[ESS-bugs] ESS 13.09-1 with old R versions fails pretty badly

[Vitalie Spinu]

 >>> Martin Maechler on Wed, 30 Oct 2013 09:57:59 +0100 wrote:

[...]

 > and sorry, but I've come to the conclusion that I very strongly
 > would like us to revert from ESSR package to the way ESS 13.09
 > worked. 

Let's do that, but with a notable difference. See below.

[...]


 > The advantage of having such non-repository package over what
 > we've had in 13.09 seems really small to me,
 >  - speed in loading, once the package is installed for the correct version of R
 >  - (one help page which still has to be complemented by ESS documentation)
 > compared to the added brittleness and non-robustness in the
 > whole setup.

Actually, the main reason was to make it work on remote
machines. Injecting long code thorough emacs shell is very
unreliable. Otherwise I would definitely not have started the revamp. I
elaborated on this problem on ess-help recently.


[...]

 > Yes, I feel bad about this; I've spent my several hours yesterday
 > that are mostly lost, but of course Vitalie, you've spent more than
 > me on this. But I strongly believe we save ourselves and even more
 > our users much hair tearing in the future if we keep this as simple
 > as we did in ESS 13.09.

Yeh ... things happen. The work is not wasted, we can reuse most of it.

 > The small speed loss (we are talking fractions of a second anyway),
 > could be eliminated in the future by providing optional save()
 > and load()ing of the ESSR code.

Let's do this, let's roll in our own simple version control system. Here
is the plan.

 - Save ESSR environment into ESSR.rda and then attach on startup. This
should be instantious. So we solve the loading speed problem.

 - On remotes we will download the binary image from a web location,
similarly to what we are doing now with ESSR<ver>.tar.gz. Then save it
in ~/.config/ESSR/ESSR.rda and ~/.config/ESSR/version. On next load we
check for "version" and re-download when outdated.

 - If loading fails, for whatever reason, we use
   ess--inject-code-from-file as we did in 13.09. This will assure that
   the stuff works on very old R and if download failed.

This is almost identical to what we have now, it should not take more
than a couple of hours to adjust.

Martin, how far backward compatible save and load is? Can you please
check this part?


   Vitalie