> Python2 -> Python3 would've been a lot less painful if you could mark,
> on a module-by-module basis, whether a module was python2 or python3
> code. It wasn't very practical for Python because python code can reach
> deep into the guts of unrelated objects discovered at runtime - it can
> add/replace member functions, even hot-patch bytecode. That's not
> something we allow in PL/PgSQL, though; from the outside a PL/PgSQL
> function is pretty opaque to callers.
Perl does this with "use <version>". Currently this guarantees that
the compiler is a minimum version and also turns OFF later version's
keywords.
At that point someone could turn on/off the appropriate syntax with
by module or code block. If you never turn on v2.0 you never get the
new behavior; after that people can adjust the amount and location
of later code to their own taste.
--
Steven Lembark 3646 Flora Pl
Workhorse Computing St Louis, MO 63110
lembark@wrkhors.com +1 888 359 3508