From: Robert Klemme <bob.news@...>
Date: 2003-11-25T19:22:21+09:00
Subject: Re: raise unless RUBY_VERSION[%r/^\s*\d+\.\d+/o].to_f >= 1.8


"T. Onoma" <transami@runbox.com> schrieb im Newsbeitrag
news:200311250144.03230.transami@runbox.com...
> On Tuesday 25 November 2003 10:07 am, Robert Klemme wrote:
> > "T. Onoma" <transami@runbox.com> schrieb im Newsbeitrag
> > news:200311250002.09555.transami@runbox.com...
> >
> > > On Tuesday 25 November 2003 08:07 am, daz wrote:
> > > > RUBY_VERSION = "1.8.1"
> > > > p  RUBY_VERSION >= "1.8"  #-> true
> > > > RUBY_VERSION = "1.10.1"
> > > > p  RUBY_VERSION >= "1.8"  #-> false
> > > >
> > > > .... but MINOR 10 would upset RUBY_VERSION_CODE (in version.h)
> > > > which, incidentally, would be a useful global (eventually).
> > > >
> > > > It might take the pressure off Matz if 1.9 didn't have to be
> > > > followed by 2.0 tho' :-)
> > > >
> > > > > unless someone can think of a reason not to - i'll take it!
> > > >
> > > > Um, because it's crufty (looks like we can't tell the difference
> > > > between Numeric and String sorting sequence - even though I've
> > > > seen it used a lot in Ruby).
> > >
> > > Any one think Ruby needs a Tuple class?
> >
> > It's already there: Array.
>
> No,
>
>   class Tuple < Array
>     include Comparable
>   end
>
>   class Array
>     def to_t
>       return Tuple.new(self)
>     end
>   end

Better define this in Enumerable:

  module Enumerable
    def to_t
      return Tuple.new(self)
    end
  end

> Now is has a Tuple. Try,
>
>   ruby_version = RUBY_VERSION.split('.').collect { |i| i.to_i }.to_t
>
>   puts ruby_version
>   puts ruby_version >= [1,7,1]
>   puts ruby_version >= [1,8]
>   puts ruby_version >= [1,8,1]
>   puts ruby_version >= [1,10]
>
> Although a Tuple  a.b.c ...  literal would look better.

Nothing easier than that.  You can do

module Kernel
  def Tuple(*a)
    a = a[0] if a.size == 1 and a[0].kind_of? Enumerable
    a = a.to_a unless a.kind_of? Array
    a.extend Comparable
  end
end

t1 = Tuple( [1,2,3] )
t2 = Tuple( 1, 3, 4 )

p t1 < t2

    robert