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On Aug 5, 2005, at 3:14:14, Mike Pall wrote:
Python has a fairly elaborate scheme with forwards and backwards compatibility, deprecation warnings and 'from __future__ import' and whatnot. Well, you may ask ... what's wrong with it? (...) Well, there's a chicken-and-egg problem with this one. The parser bails out before you can run the chunk to tell the parser that it shouldn't (and a global flag doesn't cut it).
Doesn't Lua effectively do weak-linking? I.e. couldn't one just compare the function name against NIL? An undeclared global in Lua is NIL, after all. So, if you're running a pre-compatibility-check version of Lua, you have compatmode5_0 being NIL. Otherwise, you can call it to actually query the particular feature, can't you?
Cheers, -- M. Uli Kusterer http://www.zathras.de