From: Christopher Dicely <cmdicely@...>
Date: 2010-04-19T14:24:56+09:00
Subject: Re: ruby 1.9+ , floats, and decimal

On Sun, Apr 18, 2010 at 8:07 PM, botp <botpena@gmail.com> wrote:
>> 0.2-0.1
> => 0.1
>
>> 1.2-0.1
> => 1.1
>
>> 1.2-1.1
> => 0.0999999999999999
>
> gotcha!
>
> ok, i know what you're thinking. this dead horse is double dead..
>
> in the spirit of advancing to a better computing env, shouldn't it be
> time for ruby to default to "real" decimal instead of float?

I think decimal floating point (as supported in the 2008 version of
IEEE 754) would
be a good idea. OTOH, to reduce the potential impact on existing code
-- including
on performance, where binary floating point, since it has more
prevalent hardware
support, is likely to outperform in most cases -- it might be better
to introduce a
simple syntax for decimal floating point literals, e.g. an integer or
floating point
expression with a trailing (no intervening whitespace) "d" like 1.0d
would be treated
as a decimal floating point value.