Carl Smith wrote: > I wrote:
The trouble with explicitly overriding keywords is that it still requires old code to be changed whenever a new keyword is added...
>
For the purpose of this discussion, let's say that if any code implicitly enables a new feature (by simply using it), all the code in that file is 'new code' in the context of the specific feature (a bit like how `yield` works). If `until` was a new keyword, any file that used it as a keyword would be new code. Any other files are 'old code'.
Okay, that works because it *doesn't* require old code to explicitly say "I'm using this word the old way". My comment was about the idea of having to use a backslash to escape keywords used as names, or similar schemes.
We would also allow `name.until` and `dance(until="am")` in new code, so that we can still reference names in old code (without them becoming names in new code).
Actually it would be fine if new code had to say "name.\until" etc. The only problem I can see is that it would probably be near-impossible to implement using the current parser generator. It might be doable by keeping multiple versions of the grammar -- try to parse using the most recent grammar, if that doesn't work, try the next most recent, etc. But that would be pretty horrible, and it would require keeping old cruft in the implementation forever, which we don't like doing. -- Greg _______________________________________________ Python-ideas mailing list Python-ideas@python.org https://mail.python.org/mailman/listinfo/python-ideas Code of Conduct: http://python.org/psf/codeofconduct/
