[Python-Dev] PEP 492 vs. PEP 3152, new round (original) (raw)

Greg greg.ewing at canterbury.ac.nz
Fri May 1 03:13:20 CEST 2015

On 1/05/2015 6:04 a.m., Yury Selivanov wrote:

I still want to see where my current grammar forces to use parens. See [1], there are no useless parens anywhere.

It's not about requiring or not requiring parens. It's about making the simplest possible change to the grammar necessary to achieve the desired goals. Keeping the grammar simple makes it easy for humans to reason about.

The question is whether syntactically disallowing certain constructs that are unlikely to be needed is a desirable enough goal to be worth complicating the grammar. You think it is, some others of us think it's not.

FWIW, I'll fix the 'await (await x)' expression to be parsed without parens.

I don't particularly care whether 'await -x' or 'await await x' can be written without parens or not. The point is that the simplest grammar change necessary to be able to write the things we do want also happens to allow those. I don't see that as a problem worth worrying about.

-- Greg

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