From: George Neuner <gneuner2@...>
Date: 2010-05-08T09:40:12+09:00
Subject: Re: ruby 1.9+ , floats, and decimal

On Mon, 19 Apr 2010 00:24:56 -0500, Christopher Dicely
<cmdicely@gmail.com> wrote:

>On Sun, Apr 18, 2010 at 8:07 PM, botp <botpena@gmail.com> wrote:
>
>>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. 

The decimal formats in 754-2008 are *storage* formats only ... the
math specification is still binary.


>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

More prevalent than what?  There is no commercial architecture that
has a decimal FPU.  Even integer BCD support is rare now.


>-- 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.

Just adding syntax won't help - you'd need to automagically activate
the BigDecimal class as well.

George