Microsoft Patents 'IsNot'

[Jeff Shannon]

Peter Maas wrote:

> Isnot is semantically equivalent to the inequality operator which is
> some hundred years old.


Actually, looking at the patent claim, this is *not* semantically 
equivalent to inequality.  It specifically mentions 'isNot' as something 
that compares memory addresses, which in Basic are normally hidden.  In 
other words, they are referring to something with the same semantics as 
Python's 'is not', comparing object identity rather than object equality.

 >>> [] is not []
1
 >>> [] != []
0
 >>>

It's still a pretty questionable patent, though.  Even without anyone 
explicitly having used 'is not' in Basic before, its prevalence in so 
many other languages would seem to fail the "nonobvious" test 
(supposedly) required for patent validity.

Jeff Shannon
Technician/Programmer
Credit International