[Python-ideas] [Python-ideos] Dedicated overloadable boolean operators

[Guido van Rossum]

On Mon, Nov 30, 2015 at 8:22 AM, Henry Schreiner <
henryschreineriii at gmail.com> wrote:

> Sorry, the order was incorrect in that last message. It should be:
>
> When x and y is written, if x has __booland__, then x.__booland__(y) is
> returned. If not, then return x if x==False else if x==True, then if y
>  has y.__rbooland__(x), that is returned. If not, then return y
>

This proposal isn't significantly different from PEP 335. In PEP 335, first
you ask the left operand whether to overload 'and' or not (by calling its
__and1__); if it says yes, you evaluate the second arg and ask the first to
evaluate it. In your proposal, the first question is answered by inspecting
whether x defines __booland__. I don't think this makes much practical
difference. The second part of your proposal is just a renaming of
__and2__/__rand2__ to __booland__/__rbooland__. I'm not sure I like this
much; the return type of these methods is almost never going to be an
actual bool, so the 'bool' in the name is somewhat misleading. (The names
chosen in PEP 335 are intentionally free of semantic hints, since the
intuition of someone who encounters these for the first time isn't likely
to be useful.)

-- 
--Guido van Rossum (python.org/~guido)
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