[Python-ideas] Crazy idea: allow keywords as names in certain positions

[Guido van Rossum]

As anyone still following the inline assignment discussion knows, a problem
with designing new syntax is that it's hard to introduce new keywords into
the language, since all the nice words seem to be used as method names in
popular packages. (E.g. we can't use 'where' because there's numpy.where
<https://docs.scipy.org/doc/numpy-1.14.0/reference/generated/numpy.where.html>,
and we can't use 'given' because it's used in Hypothesis
<http://hypothesis.readthedocs.io/en/latest/quickstart.html>.)

The idea I had (not for the first time :-) is that in many syntactic
positions we could just treat keywords as names, and that would free up
these keywords.

For example, we could allow keywords after 'def' and after a period, and
then the following would become legal:

class C:
    def and(self, other):
        return ...

a = C()
b = C()
print(a.and(b))

This does not create syntactic ambiguities because after 'def' and after a
period the grammar *always* requires a NAME.

There are other positions where we could perhaps allow this, e.g. in a
decorator, immediately after '@' (the only keyword that's *syntactically*
legal here is 'not', though I'm not sure it would ever be useful).

Of course this would still not help for names of functions that might be
imported directly (do people write 'from numpy import where'?). And it
would probably cause certain typos be harder to diagnose.

I should also mention that this was inspired from some messages where Tim
Peters berated the fashion of using "reserved words", waxing nostalgically
about the old days of Fortran (sorry, FORTRAN), which doesn't (didn't?)
have reserved words at all (nor significant whitespace, apart from the
"start in column 7" rule).

Anyway, just throwing this out. Please tear it apart!

-- 
--Guido van Rossum (python.org/~guido)
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