On Sat, Oct 23, 2021 at 6:23 PM Jelle Zijlstra <jelle.zijlstra@gmail.com> wrote:

In the PEP's example:

def bisect_right(a, x, lo=0, hi=>len(a), *, key=None):

This reads to me like we're putting "hi" into "len(a)", when it's in fact the reverse.

I think in most cases what's on the right side will be something that's not assignable. Likewise with the proposal to use => for lambda, someone could read (a => a + 1) as putting a into a + 1. I think they're going to get over that.

Every language I am aware of that has adopted a short hand lambda notation (without a keyword) has used => or -> except APL, Ruby, SmallTalk. See https://en.wikipedia.org/wiki/Anonymous_function

APL uses a tacit syntax while Ruby and SmallTalk use explicit syntaxes. The equivalent of x => x + 1 in each of these is

APL ⍺+1 (I think)

Ruby |x| x + 1

SmallTalk [ :x | x + 1 ]

--- Bruce