From: Dave Burt <dave@...>
Date: 2005-05-12T22:30:27+09:00
Subject: Re: Standard Library patches - rational, delegate

"gabriele renzi" <surrender_it@remove-yahoo.it> kindly suggested...
> Dave Burt ha scritto:
>> Hi,
>>
>> I have two small things I would like to see changed in the standard 
>> library:
>> delegate.rb
>> rational.rb
>
> if this is a fix you can point out the bug on the ruby issue tracker on 
> rubyforge, and attach the patch. Or you can post it on ruby-core.

Does ruby-core deal with standard library as well as core?

>> The second are some enhancements to Rational, mainly to make it more 
>> friendly with Floats and Strings, allowing rationals to be made like 
>> Rational("2/3"), Rational("1.2e-10"), Rational(0.5), as well as adding 
>> to_r methods to String and Float.
>
> This sounds more of an RCR, use RCRChive.net .

You've suggested ruby-core and RCR; I thought that as it's not a language 
change, they're not the right avenues. You have to do an explicit "require" 
to get these libraries.

Is it appropriate to submit an RCR for a standard library change?

>> 1.6.to_r  #=> Rational(3602879701896397, 2251799813685248)
>> 1.6.to_r.approximate  #=> Rational(8, 5)
>
> I wonder if this would'nt cause a problem for new users which could get 
> the false sense of security from float operations.
> Also, have you thought of intehration with BigDecimal ?
> And finaly.. I don't love the to_x methods (since there is so little room 
> for them), but in general I think your patch makes sense.

By default, the conversion is exact - the Rational is an exact 
representation of the Float's value. You need to explicitly invoke an 
approximation method.

Reciprocal integration with BigDecimal is a good suggestion, thank you for 
it.

Thanks very much for the feedback, Gabriele.

Dave.