Old versions support

[Simon Plante]

Hi,

Someone on IRC told me about a quite important lack in lilypond. A file compiled
with an older version CANNOT be compiled on a newer version. 

Well, you might want to tell me "just use the convert-ly script". The result of
that script is generally not satisfacting and often needs much hand code
reformatting.

Personnally, I didn't really experienced that problem, but when I think that
this is an important lack in a program.

Take a look at LaTeX. Using the current versions, we can easily build a 20-years
old file. With lilypond, we need to rewrite it in order to compile a 6-year old
file.

There are some ideas I could propose you:
   -- Update the convert-ly script (not the best solution, since you would need
to do that at each version).
   -- Correct the thing on lilypond, to make sure that old files can still be 
build.
   -- As LaTeX did, "freeze" the lilypond's syntax to make sure that is won't
change, and be compatible.

I cannot really help you with that, since I'm not a pretty advanced programmer.
(I probably look like whining... sorry about that ;-).

Here is the little (french) memo that I recived, that motivated me to write 
this:

"-MemoServ- IMPORTANT : envoyer un message sur mailing-list des développeurs à
propos de convert-ly : impossible de convertir des vieux fichiers, exemple
http://www.mutopiaproject.org/ftp/SatieE/gymnopedie_2/gymnopedie_2.ly Si les
fichiers lilypond ne sont pas pérennes, lilypond ne vaut guère mieux que des
logiciels propriétaires... "

Translation:

"IMPORTANt : please send a message on dev's mailling-lists about convert-ly: it
is impossible to convert old files, as propos de convert-ly : impossible de
convertir des vieux fichiers, exemple
http://www.mutopiaproject.org/ftp/SatieE/gymnopedie_2/gymnopedie_2.ly . If the
lilypond files are not perennial (old files useable on new versions), lilypond
is not better than those propertary (closed-source) software." 

I DID NOT write this, I just recived it, and sent it to you. Do what you want
with that, but it would be really useful/nice/cool to consider it.



Cheers

Simon Plante
admin of http://lilypondwiki.tuxfamily.org
founder of the lilypond's IRC channel, address@hidden