Mark Dickinson wrote:
On Jul 20, 11:34 pm, Ethan Furman <et...@stoneleaf.us> wrote:
Dr. Phillip M. Feldman wrote:
> Suppose that 'xor' returns the value that is true when only one value is
> true, and False otherwise. This definition of xor doesn't have the
standard
> associative property, that is,
>
> (a xor b) xor c
>
> will not necessarily equal
>
> a xor (b xor c)
>
> To see that this is the case, let a= 1, b= 2, and c= 3.
>
> (a xor b) xor c
>
> yields 3, while
>
> a xor (b xor c)
>
> yields 1. So, I'd prefer an xor operator that simply returns True or
False.
>
> Phillip
>
You are, of course, free to write your version however it makes sense to
you and your team. :)
Since the 'and' and 'or' already return objects (and objects evaluate to
true or false), then 'xor' should behave likewise, IMO. I expect that
would be the case if it were ever added to the language.
I'm not so sure. Did you ever wonder why the any() and all()
functions introduced in 2.5 return a boolean rather than returning
one of their arguments? (I did, and I'm still not sure what the
answer is.)
Mark
Very good question -- I likewise do not know the answer. I will only
observe that any() and all() are functions, while 'and' and 'or' are
not. If one wanted the object-returning behavior one could string
together 'or's or 'and's instead.
~Ethan~
--
Thinking out loud here -- YMMV. :)
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