[DGD] Upgrading clones with changed internal representation

[Noah Gibbs]

  The usual solution to this problem is to add fields before removing any.  You
add the new fields, use the upgrade function to put information into them, then
run a second object upgrade to delete the old fields.

  DGD currently has functionality to allow piecewise upgrade -- not everything
has to be done at one time.  So you can upgrade older instances, and the
multiple steps give you a path.

  At least, that's my understanding.  The Skotos folks have put this stuff into
practice, while I have not.  I've only done all-at-once upgrades, which *do*
work like that.

--- Carter Cheng <carter_cheng at yahoo.com> wrote:

> I am not sure I currently understand DGD well enough
> to comment on this but I am interested in getting this
> feature since without it it would be difficult to have
> full persistence. 
> 
> Wouldn't the problem be here (sorry if this sounds a
> bit newbie) that the data inside the object would
> already be potentially lost right after the
> compile_program call is made to the master copy
> forcing you to upgrade all the clones at once? 
> 
> Thanks in advance,
> 
> 
> --- Shentino <shentino at gmail.com> wrote:
> 
> > What I suggest is using call_touch on the clones so
> > that you can
> > upgrade them the instant they're played with.  Sorta
> > like java's
> > "JIT", only with upgrading.  The point is that the
> > clone would be
> > upgraded "just in time".  A background of 0-second
> > callouts to mop up
> > the clone mob in the meantime would keep things neat
> > in any case.
> > 
> > At any rate, you'll need to make sure that any clone
> > can be upgraded
> > on the spot the moment it's been played with after
> > an upgrade.  To do
> > that, you'll either need to catch old clones as they
> > are found (or
> > used), or put the mud on hold while you upgrade
> > everything.
> > 
> > A good solution would probably be something like
> > Skotos's "patch" thingy.
> > ___________________________________________
> > https://mail.dworkin.nl/mailman/listinfo/dgd
> > 
> 
> ___________________________________________
> https://mail.dworkin.nl/mailman/listinfo/dgd
> 





       
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