From: Jason Roelofs <jameskilton@...>
Date: 2008-05-08T21:50:25+09:00
Subject: Re: Why can't I redefine "<<" method to allow two parameters?

On Thu, May 8, 2008 at 8:42 AM, Iņaki Baz Castillo <ibc@aliax.net> wrote:
> Hi, very exrtange:
>
>
> class MyArray < Array
>  alias original_add <<
>  def <<(n,k)
>    original_add "#{n}: #{k}"
>  end
> end
>
> my_array = MyArray.new
> => []
>
> my_array << ("Header", "Value")
>
> SyntaxError: compile error
> (irb):25: syntax error, unexpected ',', expecting ')'
> my_array << ("Header", "Value")
>                         ^
>
>
> Any reason for this? It seems that << is a littled "hardcoded", isn't?
>
> --
> Iņaki Baz Castillo
> <ibc@aliax.net>
>

The << operator is a special case handled by the parser, but you can
bypass that handling by calling the method directly:

my_array.<<("Header", "Value")

which will of course look a ton better by just using a custom method:

my_array.add_stuff "Header", "Value"

Jason R.