Feature #4786: RCR new Feature: Numeric#grouped

• Status: Rejected
• Assignee: mame (Yusuke Endoh)
• Target version: -

[rogerdpack (Roger Pack)]

Hello all.

As discussed in http://www.ruby-forum.com/topic/1060694#new with apparently no objection, this is a request for an easy way to get comma separated string values from numeric types.

Background:
Currently in ruby you can enter large numbers with digit grouping:
a = 1_000_000_000

however there is no convenient way to convert from a number back to digit grouping

Suggestion:

1_000_000_000.grouped
=> "1,000,000,000"

class Numeric
def separate(sep=",")
self.to_s.reverse.scan(/(?:\d*.)?\d{1,3}-?/).join(sep).reverse
end
end

Another option would be to support this extended printf syntax:

"%'d" % 12345678
=> 12,345,678

Though I'd lean toward the former.

Feedback?
Thanks.
-roger-

[nobu (Nobuyoshi Nakada)]

Hi,

At Fri, 27 May 2011 07:22:37 +0900,
Roger Pack wrote in [ruby-core:36494]:

Background:
Currently in ruby you can enter large numbers with digit grouping:
a = 1_000_000_000

however there is no convenient way to convert from a number back to digit grouping

Suggestion:

1_000_000_000.grouped
=> "1,000,000,000"

If you use round-tripping as the base, the separater should be
"_" by default.

class Numeric
def separate(sep=",")
self.e
end
end

It makes 12323.separate("xy") "12yx323", which does not seem
nice.

And not all locales use 3-digits separation.

def separate(n, sep="_")
to_s.gsub(/\G(?<!\d)(?<=\d{#{n}})(?=\d)|(?<=\d)(?=\d{#{n}}+\b)/, sep)
end

--
Nobu Nakada

[shyouhei (Shyouhei Urabe)]

-1.

As nobu said numbering system depends on locales. So far ruby has been strictly avoiding locale-dependent features. It is too careless to introduce such feature.

[shyouhei (Shyouhei Urabe)]

P.S. POSIX does specify printf("%'d"), but this does not define how the numbers are grouped, because of course, by theory they cannot.

[nobu (Nobuyoshi Nakada)]

Hi,

At Fri, 27 May 2011 08:17:52 +0900,
Nobuyoshi Nakada wrote in [ruby-core:36495]:

And not all locales use 3-digits separation.

According to
http://en.wikipedia.org/wiki/Indian_numbering_system, it's
more complicated than I've thought.

Therefore I'm against it now.

--
Nobu Nakada

[naruse (Yui NARUSE)]

Ruby doesn't include Locale depended features on current policy.
So it should be done by ICU or ActiveSupport or something.

[mame (Yusuke Endoh)]

• Status changed from Open to Assigned
• Assignee set to mame (Yusuke Endoh)

[duerst (Martin Dürst)]

• Status changed from Assigned to Rejected

naruse (Yui NARUSE) wrote:

Ruby doesn't include Locale depended features on current policy.
So it should be done by ICU or ActiveSupport or something.

We have looked at this issue today at our Ruby developer meeting in Akihabara, and we agree with Yui. We have therefore rejected this issue.

On 5/26/11, Shyouhei Urabe [e-mail] wrote:

Issue #4786 has been updated by Shyouhei Urabe.

-1.

As nobu said numbering system depends on locales. So far ruby has been
strictly avoiding locale-dependent features. It is too careless to
introduce such feature.

I'd be down with some local independent implementation, like java's
new DecimalFormat( "#,###,###,##0.00" );
basically.
Cheers!
roger