On 13/05/2018 19:19, Guido van Rossum wrote:
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).
So you would be allowing "second class" identifiers - legal in some
positions where an identifier is allowed, not legal in others.
With respect, that seems like a terrible idea; neither those who want to
use such identifiers, nor those who don't, would be happy. Especially
if it encourages work-arounds such as
def and(x, y):
return ...
# and(1,2) # Oops, SyntaxError. Oh, I know:
globals()['and'](1,2) # Works!
and a zillion others.
[snip] And it would probably cause certain typos be harder to diagnose.
No doubt.
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!
Thanks. :-)
--
--Guido van Rossum (python.org/~guido <http://python.org/%7Eguido>)
Best wishes
Rob Cliffe
_______________________________________________
Python-ideas mailing list
Python-ideas@python.org
https://mail.python.org/mailman/listinfo/python-ideas
Code of Conduct: http://python.org/psf/codeofconduct/
