From: mathew <meta@...>
Date: 2011-01-13T01:35:40+09:00
Subject: [ruby-core:34442] Re: ext/bigdecimal/lib/bigdecimal/util.rb

On Tue, Jan 11, 2011 at 01:14, Aaron Patterson
<aaron@tenderlovemaking.com> wrote:
> On Tue, Jan 11, 2011 at 03:11:14PM +0900, Kenta Murata wrote:
>> Float is difficult.
>> The radix of Float may be different from BigDecimal so some Floats
>> aren't able to convert to BigDecimal without error.
>> For example 10.1 isn't represented in Float precisely:
>>
>> � 10.1.to_r #=> (5685794529555251/562949953421312)
>>
>> This is not 10.1.
>> You have to specify a precision for conversion if you convert
>> 10.1 to BigDecimal.
>> For any Float values, we have to specify precisions for converting
>> to BigDecimal.
>
> True, but we still have this problem with String => BigDecimal.

Eh? Surely any string will have finite length, and hence a finite
base-10 representation. Thus it can convert to a BigDecimal without
error.

We're only talking about strings containing base-10 numbers, right?


mathew