From: Peter Vandenabeele <peter@...>
Date: 2012-01-23T19:51:36+09:00
Subject: Re: Microrant on Ruy's Math Skills

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On Mon, Jan 23, 2012 at 11:40 AM, Robert Klemme
<shortcutter@googlemail.com>wrote:

> On Mon, Jan 23, 2012 at 11:35 AM, Peter Vandenabeele
> <peter@vandenabeele.com> wrote:
> > On Mon, Jan 23, 2012 at 11:33 AM, Peter Vandenabeele <
> peter@vandenabeele.com
>
> >> Feature request:
> >>
> >> Based on this discussion, it would actually be useful to me if I could
> >> shorten this:
> >>
> >>   amount = BigDecimal.new("15.5")
> >>
> >> to
> >>
> >>   amount = 15.5B
>
> Bad idea IMHO because this requires a parser change and also makes all
> programs implicitly require "bigdecimal" which is usually not needed.
>
> > Maybe
> >
> > 15.5D
> >
> > is better naming (maps to "Decimal" and the %d of format string).
>
> Or
>
> amount = 15.4.to_bd
> amount = 15.4.to_decimal
> amount = 15.4.to_dec
> amount = BD(15.4)
>

When writing 15.4 ... and then calling a method on it,
it's already too late.

BD("15.4") would work though ...

1.9.3p0 :001 > def BD(number)
1.9.3p0 :002?>   BigDecimal.new(number)
1.9.3p0 :003?>   end
 => nil
1.9.3p0 :004 > def BD_from_string(string)
1.9.3p0 :005?>   BigDecimal.new(string)
1.9.3p0 :006?>   end
 => nil
1.9.3p0 :007 > BD(15.4)
NameError: uninitialized constant BigDecimal
    from (irb):2:in `BD'
    from (irb):7
    from /home/peterv/.rvm/rubies/ruby-1.9.3-p0/bin/irb:16:in `<main>'
1.9.3p0 :008 > require 'bigdecimal'
 => true
1.9.3p0 :009 > BD(15.4)
ArgumentError: can't omit precision for a Rational.
    from (irb):2:in `new'
    from (irb):2:in `BD'
    from (irb):9
    from /home/peterv/.rvm/rubies/ruby-1.9.3-p0/bin/irb:16:in `<main>'
1.9.3p0 :010 > BD_from_string("15.4")
 => #<BigDecimal:96787bc,'0.154E2',18(18)>

Peter

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