0 + not 0

Gregory Ewing greg.ewing at canterbury.ac.nz
Sun Jul 12 08:12:00 CEST 2015


Ian Kelly wrote:
> I must concur. The grammar as written does not actually produce 1 +
> not 0. I think it's still worthwhile opening a bug, because the
> behavior is surprising and possibly not intentional.

It's almost certainly intentional. If you want

    not a + b > c

to be interpreted as

    not (a + b > c)

rather than

    (not a) + b > c

then 'not' has to be higher up in the chain of
grammar productions than the arithmetic operations.
Maintaining that while allowing 'a + not b' would
require contortions in the grammar that wouldn't be
worth the very small benefit that would be obtained.

-- 
Greg


More information about the Python-list mailing list