Boolean tests [was Re: Attack a sacred Python Cow]

Antoon Pardon apardon at forel.vub.ac.be
Fri Aug 1 04:35:12 EDT 2008


On 2008-08-01, Erik Max Francis <max at alcyone.com> wrote:
> Antoon Pardon wrote:
>
>> I now have the following question for people who argue that "if x"
>> is more polymorphic. I could subclass list, so that instances
>> of this new sequence would always behave as true, even if they are
>> empty.  I could then rewrite my loop as follows:
>> 
>> while 1:
>>   extra = produce()
>>   if not extra:
>>     break
>>   for el in extra:
>>     adjust_with(el)
>>   calculate()
>> 
>> Is this second loop now more polymorphic as the first?
>
> It's more confusing since you've changed the standard behavior of a 
> standard type, which doesn't really have anything to do with 
> polymorphism.  It's more confusing, if that's a benefit.

So you accept my point that "if x" can be less polymorphic
and in fact can be more confusing than a more specific test.

-- 
Antoon Pardon



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