Phrogz wrote:
[...]
> Now, I would consider it a valid argument to say "Let's not codify a
> particular interpetation of some syntax that conflicts with another
> reasonable interpretation, because it will be surprising to a notable
> percentage of programmers." Would anyone say that they personally have
> a different expectation for what "a,b += x,y" might mean?

"The same as
   a,b = a,b + x,y
  but with a,b evaluated only once"?

(?)

--