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From: Chris Angelico <rosuav@gmail.com>
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Subject: Re: Clean Singleton Docstrings
Date: Sat, 16 Jul 2016 17:27:43 +1000
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On Sat, Jul 16, 2016 at 4:53 PM, Random832 <random832@fastmail.com> wrote:
> On Sat, Jul 16, 2016, at 02:29, Chris Angelico wrote:
>> The difference between ints and floats can lead to bugs, too. Which
>> one should we eliminate?
>
> Eliminate both of them. Move to a single abstract numeric type* a la
> Scheme, with an "inexact" attribute (inexact numbers may or may not be
> represented by a float, or by the same bigint/decimal/rational types as
> exact ones with a flag set to mark them as inexact.)
>
> *which may have multiple concrete representations, just as our single
> abstract unicode string type has different concrete representations for
> ASCII, Latin-1, UCS-2, and UCS-4.

Thing is, a Unicode string could be represented in exactly one way
(UCS-4), with identical semantics. Look at Py2's "wide build" (eg most
Linux builds). The rest is just optimization. With a single abstract
numeric type, what exactly does "inexact" mean, where does it come
from, and how does that affect the expected behaviour and performance
of numbers? Will an "Exact" non-integer be stored as Decimal or
Fraction? How do you know? They have vastly different semantics, and
you should be able to choose.

ChrisA