On 21/03/2019 11:34, Antoine Pitrou wrote:
On Wed, 20 Mar 2019 15:46:24 -1000
Christopher Barker <python...@gmail.com>
wrote:
This is precisely why I worded my question this way: what has changed
in the last 20 years that make a "+" dict operator more compelling
today than it was? Do we merge dicts much more frequently than we
did?
The analogy doesn't hold because @ was a new operator -- a MUCH bigger
change than dimply defining the use of + (or | ) for dicts.
But it's less disruptive when reading code, because "x @ y" is
unambiguous: it's a matrix multiplication. "x + y" can be many
different things, and now it can be one more thing.
"x @ y" is unambiguous once you know what it means. Until then, it's
just mysterious.
I wouldn't mind the new operator if its meaning was clear-cut. But
here we have potential for confusion, both for writers and readers of
code.
but it's NOT a new operator, it is making use of an existing one, and sure
you could guess at a couple meanings, but the merge one is probably one of
the most obvious to guess, and one quick test and you know -- I really
can't see it being a ongoing source of confusion.
Did you actually read what I said? The problem is not to understand
what dict.__add__ does. It's to understand what code using the +
operator does, without knowing upfront whether the inputs are dicts.
Welcome to polymorphism.
--
Rhodri James *-* Kynesim Ltd
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