[isabelle-dev] Mercurial conversion relaunch

[Makarius]

On Thu, 4 Sep 2008, Lawrence Paulson wrote:

> Changing revision control systems would be a major upheaval, so I hope 
> it will bring clear benefits.

Definitely.  This is also the reason why we did not switch to SVN some 
years ago, because the conversion would have been the same effort, but 
with very few benefits.


> First, as a very obvious point, I assume that there is a way of 
> importing the entire revision history (not just the current snapshot) 
> into the new system.

This is what we have already, and the reason why the relaunch yesterday 
took approx 4 hours, to import 15 years of history. (Some bits of the 
history are actually missing in the CVS: there is no HOL before 1995, 
because the CVS was changed directly at that time to replace HOL by the 
new "Curried HOL".  See 
http://isabelle.in.tum.de/repos/isabelle/rev/ff1574a81019)


> My particular concern would be the state of user interface support for 
> Mercurial.

So far I have mostly used the web interface or the command line.  There is 
full support for Mercurial in the Netbeans editing environment from Sun.  
I have also seen basic VCS support in recent GNU Emacs.  There are some 
generic UI projects for all kinds of version systems.  It will probably 
take a few more years until everybody's editor will be ready.

See also http://www.selenic.com/mercurial/wiki/index.cgi/GUIClients for 
more information.  There are also a few Mac tools, although I have not 
tried any of them yet.


	Makarius