From: Rick DeNatale <rick.denatale@...>
Date: 2008-05-09T01:07:11+09:00
Subject: Re: Why can't I redefine "<<" method to allow two parameters?

On Thu, May 8, 2008 at 10:18 AM, David A. Black <dblack@rubypal.com> wrote:
> Hi --

>  On Thu, 8 May 2008, Iņaki Baz Castillo wrote:

> > 2008/5/8, Jens Wille <jens.wille@uni-koeln.de>:
> >
> > > Jason Roelofs [2008-05-08 14:50]:
> > >
> > >
> > > > On Thu, May 8, 2008 at 8:42 AM, Iņaki Baz Castillo <ibc@aliax.net>
> wrote:
> > > >
> > > the point is that you can't call an operator with multiple
> > >  arguments. maybe something like this will suit you (note that you
> > >  don't need to alias if you inherit from Array):
> > >
> > >  class MyArray < Array
> > >    def <<(*a)
> > >      a = [*(a=*a)]  # a.to_a.flatten_once ;-)
> > >      raise ArgumentError, "wrong number of arguments (#{a.size} for
> > >  2)" if a.size != 2
> > >
> > >      super a.join(': ')
> > >
> > >    end
> > >  end
> > >
> > >  my_array = MyArray.new
> > >
> > >  my_array << ['Header1', 'Value1']  # => ["Header1: Value1"]
> > >  my_array.<<('Header2', 'Value2')   # => ["Header1: Value1",
> > >  "Header2: Value2"]
> > >
> >
> >
> > Thanks to all. Finally I'll just create a "add" method that will call
> > internally to << method using appropiate syntax:
> >  self.<< (k, v)
> >
>
>  I would just use Array#push:
>
>
> >
> > > [1,2,3].push(4,5)
> > >
> >
>  => [1, 2, 3, 4, 5]

We seem to have lost track of what the OP was trying to do,

class MyArray < Array
 alias original_add <<
 def <<(n,k)
   original_add "#{n}: #{k}"
 end
end

He wants

[1,2,3].whatever_the_heck_he_decides_to_call_it(4,5) #=>  [1,2,3, "4:5"]


-- 
Rick DeNatale

My blog on Ruby
http://talklikeaduck.denhaven2.com/