[Python-Dev] Re: ANN: PEP 335: Overloadable Boolean Operators

Tim Hochberg tim.hochberg at ieee.org
Tue Sep 14 21:50:00 CEST 2004


Phillip J. Eby wrote:

[CHOP]
>
> As for the numeric use cases, I'm not at all clear why &, |, and ~ (or 
> special methods/functions) aren't suitable.

They often are, but sometimes you want a logical and/or/not and &/|/~ 
are mapped to bitwise and/or/not, which isn't always what you want. 
Presumably, if Gregs proposal were adopted, and/or/not would get mapped 
to numarray.logical_and/or/not.

What I find more interesting about this proposal is that one could 
probably finagle it so that (A < B < C) worked correctly for arrays. It 
can't work now since it is equivalent to ((A < B) and (B < C)) and 'and' 
  doesn't do anything sensible for arrays at present. This is one I 
always expect to work even though I know that and/or/not don't work for 
arrays.

-tim



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