[Python-ideas] float('∞')=float('inf')

[Serhiy Storchaka]

14.07.13 11:56, Joshua Landau написав(ла):
> On 14 July 2013 09:40, Serhiy Storchaka <storchaka at gmail.com> wrote:
>> 13.07.13 00:55, Joshua Landau wrote:
>>> On 12 July 2013 22:46, Serhiy Storchaka wrote:
>>>> 13.07.13 00:27, Joshua Landau wrote:
>>>>>
>>>>> ½ === 1/2; thus is an expression
>>>>
>>>> 0.5 === 5/10. Isn't it an expression?
>>>
>>> No. That's like saying "1 === 2/2". There is a much more obvious
>>> equivalence between two ways of writing "1/2" than between two ways of
>>> displaying the result of "1/2".
>>
>> 0.5 is 5/10 by definition. The result of 1/2 is a fraction ½.
>
> I don't understand. What are you trying to say?

0.5 is a spelling of 5⁄10 which is a result of expression 5/10. ½ is a 
spelling of 1⁄2 which is a result of expression 1/2. I don't understand 
why you think 1⁄2 is expression while 5⁄10 is not.

>>> Plus, why on earth would you use recurrence for floats? Give me a use
>>> case. There's a good reason for float infinity.
>>
>> This is only a way to spell a general fraction in decimal. On other hand, ∞
>> is even not a real number.
>
> That's not a use-case.

∞ is not a use-case.

>> If you accept ∞ you are bound by law to accept ½ and all of the other
>> fractions — and that's much more code than just allowing ∞.
>
> I was afraid that people would go and take this too literally. But
> either way, if you accept ½ and reject ¾, you have made a really bad
> design decision. If you accept ∞ and reject ½, the atrocity of that
> decision is much less. I would say it's a good choice, you may say it
> is bad. But if you say those are equivalently bad decisions you're
> simply wrong and there's not much more I can say.

The difference between this two bad choices is far less than the 
difference between good and bad. Why should we choose between two bad 
designs?