[Python-Dev] closure semantics
Guido van Rossum
guido at python.org
Thu Nov 6 00:30:51 EST 2003
> >>>So it can't be global, as it must stay a keyword for backwards
> >>>compatibility at least until 3.0.
> >>Why? Removing keywords should be much simpler than adding them. I
> >>have no idea how hard it is to hack the parser to adjust, but I
> >>can't imagine how having 'global' no longer be a keyword as far as
> >>its concerned break b/w compatibility.
> >>What am I missing?
> > I don't recall the context, but I think the real issue with removing
> > 'global' is that there's too much code out there that uses the global
> > syntax to remove the global statement before 3.0.
> I would never have suggested that. Just that we can evolve the parser
> to retain the old usage
> global a,b,c
> while allowing a new usage
> global.a = value
> by removing 'global' from the list of reserved words and doing "fancy
> stuff" in the parser. Note that I very much don't know the details
> of the "fancy stuff".
Ah. *If* we want to parse both it would be easier to keep global as a
keyword and do fancy stuff to recognize the second form...
But I think somewhere in the mega-thread about this topic is hidden
the conclusion that there are better ways to do this.
--Guido van Rossum (home page: http://www.python.org/~guido/)
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